[libvirt PATCH v4 00/11] remote: introduce a custom netcat impl for ssh tunnelling
We have long had a problem with use of netcat for ssh tunnelling because there's no guarantee the UNIX socket path the client builds will match the UNIX socket path the remote host uses. We don't even allow session mode SSH tunnelling for this reason. We also can't easily auto-spawn libvirtd in session mode. With the introduction of modular daemons we also have potential for two completely different UNIX socket paths even for system mode, and the client can't know which to use. The solution to all these problems is to introduce a custom netcat impl. Instead passing the UNIX socket path, we pass the libvirt driver URI. The custom netcat then decides which socket path to use based on the remote build host environment. We still have to support netcat for interoperability with legacy libvirt versions, but we can default to the new virt-nc. v4: Now with many fixed bugs to make it actually work v3: Now with more meson and less autotools ! Daniel P. Berrangé (11): rpc: merge logic for generating remote SSH shell script remote: push logic for default netcat binary into common helper remote: split off enums into separate source file remote: split out function for parsing URI scheme remote: parse the remote transport string earlier remote: split out function for constructing socket path remote: extract logic for determining daemon to connect to remote: introduce virt-ssh-helper binary rpc: switch order of args in virNetClientNewSSH rpc: use new virt-ssh-helper binary for remote tunnelling remote: fix error reporting for invalid daemon mode build-aux/syntax-check.mk | 2 +- docs/uri.html.in | 24 +- libvirt.spec.in | 2 + po/POTFILES.in | 2 + src/libvirt_remote.syms | 1 + src/remote/meson.build | 18 ++ src/remote/remote_driver.c | 331 +++++-------------------- src/remote/remote_sockets.c | 277 +++++++++++++++++++++ src/remote/remote_sockets.h | 70 ++++++ src/remote/remote_ssh_helper.c | 425 +++++++++++++++++++++++++++++++++ src/rpc/virnetclient.c | 167 +++++++++---- src/rpc/virnetclient.h | 29 ++- src/rpc/virnetsocket.c | 37 +-- src/rpc/virnetsocket.h | 4 +- tests/virnetsockettest.c | 12 +- 15 files changed, 1030 insertions(+), 371 deletions(-) create mode 100644 src/remote/remote_sockets.c create mode 100644 src/remote/remote_sockets.h create mode 100644 src/remote/remote_ssh_helper.c -- 2.26.2
Three parts of the code all build up the same SSH shell script snippet for remote tunneling the RPC protocol, but in slightly different ways. Combine them all into one helper method in the virNetClient code, since this logic doesn't really belong in the virNetSocket code. Note that the this change means the shell snippet is passed to the SSH binary as a single arg, instead of three separate args, but this is functionally identical, as the three separate args were combined into one already when passed to the remote system. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/libvirt_remote.syms | 1 + src/rpc/virnetclient.c | 108 ++++++++++++++++++++------------------- src/rpc/virnetclient.h | 3 ++ src/rpc/virnetsocket.c | 37 +------------- src/rpc/virnetsocket.h | 3 +- tests/virnetsockettest.c | 9 +++- 6 files changed, 69 insertions(+), 92 deletions(-) diff --git a/src/libvirt_remote.syms b/src/libvirt_remote.syms index 0018a0c41d..0b00bce1fa 100644 --- a/src/libvirt_remote.syms +++ b/src/libvirt_remote.syms @@ -42,6 +42,7 @@ virNetClientSendStream; virNetClientSendWithReply; virNetClientSetCloseCallback; virNetClientSetTLSSession; +virNetClientSSHHelperCommand; # rpc/virnetclientprogram.h diff --git a/src/rpc/virnetclient.c b/src/rpc/virnetclient.c index 441f1502a6..bd818df953 100644 --- a/src/rpc/virnetclient.c +++ b/src/rpc/virnetclient.c @@ -391,28 +391,74 @@ virNetClientPtr virNetClientNewTCP(const char *nodename, return virNetClientNew(sock, nodename); } + +/* + * The SSH Server uses shell to spawn the command we give + * it. Our command then invokes shell again. Thus we need + * to apply two levels of escaping, so that commands with + * whitespace in their path get correctly interpreted. + */ +static char * +virNetClientDoubleEscapeShell(const char *str) +{ + virBuffer buf = VIR_BUFFER_INITIALIZER; + g_autofree char *tmp = NULL; + + virBufferEscapeShell(&buf, str); + + tmp = virBufferContentAndReset(&buf); + + virBufferEscapeShell(&buf, tmp); + + return virBufferContentAndReset(&buf); +} + +char * +virNetClientSSHHelperCommand(const char *netcatPath, + const char *socketPath) +{ + g_autofree char *netcatPathSafe = virNetClientDoubleEscapeShell(netcatPath); + + return g_strdup_printf( + "sh -c " + "'if '%s' -q 2>&1 | grep \"requires an argument\" >/dev/null 2>&1; then " + "ARG=-q0;" + "else " + "ARG=;" + "fi;" + "'%s' $ARG -U %s'", + netcatPathSafe, netcatPathSafe, socketPath); +} + + +#define DEFAULT_VALUE(VAR, VAL) \ + if (!VAR) \ + VAR = VAL; + virNetClientPtr virNetClientNewSSH(const char *nodename, const char *service, const char *binary, const char *username, bool noTTY, bool noVerify, - const char *netcat, + const char *netcatPath, const char *keyfile, - const char *path) + const char *socketPath) { virNetSocketPtr sock; + g_autofree char *command = NULL; + + DEFAULT_VALUE(netcatPath, "nc"); + + command = virNetClientSSHHelperCommand(netcatPath, socketPath); if (virNetSocketNewConnectSSH(nodename, service, binary, username, noTTY, - noVerify, netcat, keyfile, path, &sock) < 0) + noVerify, keyfile, command, &sock) < 0) return NULL; return virNetClientNew(sock, NULL); } -#define DEFAULT_VALUE(VAR, VAL) \ - if (!VAR) \ - VAR = VAL; virNetClientPtr virNetClientNewLibSSH2(const char *host, const char *port, int family, @@ -427,11 +473,7 @@ virNetClientPtr virNetClientNewLibSSH2(const char *host, virURIPtr uri) { virNetSocketPtr sock = NULL; - - g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER; - g_autofree char *nc = NULL; g_autofree char *command = NULL; - g_autofree char *homedir = NULL; g_autofree char *confdir = NULL; g_autofree char *knownhosts = NULL; @@ -442,9 +484,7 @@ virNetClientPtr virNetClientNewLibSSH2(const char *host, knownhosts = g_strdup(knownHostsPath); } else { confdir = virGetUserConfigDirectory(); - virBufferAsprintf(&buf, "%s/known_hosts", confdir); - if (!(knownhosts = virBufferContentAndReset(&buf))) - return NULL; + knownhosts = g_strdup_printf("%s/known_hosts", confdir); } if (privkeyPath) { @@ -468,26 +508,7 @@ virNetClientPtr virNetClientNewLibSSH2(const char *host, DEFAULT_VALUE(netcatPath, "nc"); DEFAULT_VALUE(knownHostsVerify, "normal"); - virBufferEscapeShell(&buf, netcatPath); - if (!(nc = virBufferContentAndReset(&buf))) - return NULL; - virBufferEscapeShell(&buf, nc); - VIR_FREE(nc); - if (!(nc = virBufferContentAndReset(&buf))) - return NULL; - - virBufferAsprintf(&buf, - "sh -c " - "'if '%s' -q 2>&1 | grep \"requires an argument\" >/dev/null 2>&1; then " - "ARG=-q0;" - "else " - "ARG=;" - "fi;" - "'%s' $ARG -U %s'", - nc, nc, socketPath); - - if (!(command = virBufferContentAndReset(&buf))) - return NULL; + command = virNetClientSSHHelperCommand(netcatPath, socketPath); if (virNetSocketNewConnectLibSSH2(host, port, family, @@ -498,11 +519,7 @@ virNetClientPtr virNetClientNewLibSSH2(const char *host, return virNetClientNew(sock, NULL); } -#undef DEFAULT_VALUE -#define DEFAULT_VALUE(VAR, VAL) \ - if (!VAR) \ - VAR = VAL; virNetClientPtr virNetClientNewLibssh(const char *host, const char *port, int family, @@ -517,11 +534,7 @@ virNetClientPtr virNetClientNewLibssh(const char *host, virURIPtr uri) { virNetSocketPtr sock = NULL; - - g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER; - g_autofree char *nc = NULL; g_autofree char *command = NULL; - g_autofree char *homedir = NULL; g_autofree char *confdir = NULL; g_autofree char *knownhosts = NULL; @@ -556,18 +569,7 @@ virNetClientPtr virNetClientNewLibssh(const char *host, DEFAULT_VALUE(netcatPath, "nc"); DEFAULT_VALUE(knownHostsVerify, "normal"); - virBufferEscapeShell(&buf, netcatPath); - if (!(nc = virBufferContentAndReset(&buf))) - return NULL; - virBufferEscapeShell(&buf, nc); - VIR_FREE(nc); - if (!(nc = virBufferContentAndReset(&buf))) - return NULL; - - command = g_strdup_printf("sh -c " - "'if '%s' -q 2>&1 | grep \"requires an argument\" >/dev/null 2>&1; then " - "ARG=-q0;" "else " "ARG=;" "fi;" "'%s' $ARG -U %s'", nc, nc, - socketPath); + command = virNetClientSSHHelperCommand(netcatPath, socketPath); if (virNetSocketNewConnectLibssh(host, port, family, diff --git a/src/rpc/virnetclient.h b/src/rpc/virnetclient.h index 778910b575..0005de46f3 100644 --- a/src/rpc/virnetclient.h +++ b/src/rpc/virnetclient.h @@ -30,6 +30,9 @@ #include "virobject.h" #include "viruri.h" +char * +virNetClientSSHHelperCommand(const char *netcatPath, + const char *socketPath); virNetClientPtr virNetClientNewUNIX(const char *path, bool spawnDaemon, diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c index 977d2875fe..485e8229a8 100644 --- a/src/rpc/virnetsocket.c +++ b/src/rpc/virnetsocket.c @@ -862,14 +862,11 @@ int virNetSocketNewConnectSSH(const char *nodename, const char *username, bool noTTY, bool noVerify, - const char *netcat, const char *keyfile, - const char *path, + const char *command, virNetSocketPtr *retsock) { - char *quoted; virCommandPtr cmd; - g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER; *retsock = NULL; @@ -894,38 +891,8 @@ int virNetSocketNewConnectSSH(const char *nodename, if (noVerify) virCommandAddArgList(cmd, "-o", "StrictHostKeyChecking=no", NULL); - if (!netcat) - netcat = "nc"; - - virCommandAddArgList(cmd, "--", nodename, "sh", "-c", NULL); - - virBufferEscapeShell(&buf, netcat); - quoted = virBufferContentAndReset(&buf); + virCommandAddArgList(cmd, "--", nodename, command, NULL); - virBufferEscapeShell(&buf, quoted); - VIR_FREE(quoted); - quoted = virBufferContentAndReset(&buf); - - /* - * This ugly thing is a shell script to detect availability of - * the -q option for 'nc': debian and suse based distros need this - * flag to ensure the remote nc will exit on EOF, so it will go away - * when we close the connection tunnel. If it doesn't go away, subsequent - * connection attempts will hang. - * - * Fedora's 'nc' doesn't have this option, and defaults to the desired - * behavior. - */ - virCommandAddArgFormat(cmd, - "'if '%s' -q 2>&1 | grep \"requires an argument\" >/dev/null 2>&1; then " - "ARG=-q0;" - "else " - "ARG=;" - "fi;" - "'%s' $ARG -U %s'", - quoted, quoted, path); - - VIR_FREE(quoted); return virNetSocketNewConnectCommand(cmd, retsock); } diff --git a/src/rpc/virnetsocket.h b/src/rpc/virnetsocket.h index f2b74f3ccb..d39b270480 100644 --- a/src/rpc/virnetsocket.h +++ b/src/rpc/virnetsocket.h @@ -78,9 +78,8 @@ int virNetSocketNewConnectSSH(const char *nodename, const char *username, bool noTTY, bool noVerify, - const char *netcat, const char *keyfile, - const char *path, + const char *command, virNetSocketPtr *addr); int virNetSocketNewConnectLibSSH2(const char *host, diff --git a/tests/virnetsockettest.c b/tests/virnetsockettest.c index 96c582216c..31fe1f86f4 100644 --- a/tests/virnetsockettest.c +++ b/tests/virnetsockettest.c @@ -32,6 +32,7 @@ #include "virstring.h" #include "rpc/virnetsocket.h" +#include "rpc/virnetclient.h" #define VIR_FROM_THIS VIR_FROM_RPC @@ -468,6 +469,8 @@ static int testSocketSSH(const void *opaque) virNetSocketPtr csock = NULL; /* Client socket */ int ret = -1; char buf[1024]; + g_autofree char *command = virNetClientSSHHelperCommand(data->netcat, + data->path); if (virNetSocketNewConnectSSH(data->nodename, data->service, @@ -475,9 +478,8 @@ static int testSocketSSH(const void *opaque) data->username, data->noTTY, data->noVerify, - data->netcat, data->keyfile, - data->path, + command, &csock) < 0) goto cleanup; @@ -575,6 +577,7 @@ mymain(void) struct testSSHData sshData1 = { .nodename = "somehost", .path = "/tmp/socket", + .netcat = "nc", .expectOut = "-T -e none -- somehost sh -c '" "if 'nc' -q 2>&1 | grep \"requires an argument\" >/dev/null 2>&1; then " "ARG=-q0;" @@ -635,6 +638,7 @@ mymain(void) struct testSSHData sshData5 = { .nodename = "crashyhost", .path = "/tmp/socket", + .netcat = "nc", .expectOut = "-T -e none -- crashyhost sh -c " "'if 'nc' -q 2>&1 | grep \"requires an argument\" >/dev/null 2>&1; then " "ARG=-q0;" @@ -650,6 +654,7 @@ mymain(void) struct testSSHData sshData6 = { .nodename = "example.com", .path = "/tmp/socket", + .netcat = "nc", .keyfile = "/root/.ssh/example_key", .noVerify = true, .expectOut = "-i /root/.ssh/example_key -T -e none -o StrictHostKeyChecking=no -- example.com sh -c '" -- 2.26.2
We don't want to repeat the choice of default netcat binary setting in three different places. This will also make it possible to do better error reporting in the helper. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/remote/remote_driver.c | 2 +- src/rpc/virnetclient.c | 5 +++-- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index 0331060a2d..f511a9bc33 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -1226,7 +1226,7 @@ doRemoteOpen(virConnectPtr conn, username, !tty, !verify, - netcat ? netcat : "nc", + netcat, keyfile, sockname))) goto failed; diff --git a/src/rpc/virnetclient.c b/src/rpc/virnetclient.c index bd818df953..f65cda0d7f 100644 --- a/src/rpc/virnetclient.c +++ b/src/rpc/virnetclient.c @@ -419,6 +419,9 @@ virNetClientSSHHelperCommand(const char *netcatPath, { g_autofree char *netcatPathSafe = virNetClientDoubleEscapeShell(netcatPath); + if (!netcatPath) + netcatPath = "nc"; + return g_strdup_printf( "sh -c " "'if '%s' -q 2>&1 | grep \"requires an argument\" >/dev/null 2>&1; then " @@ -505,7 +508,6 @@ virNetClientPtr virNetClientNewLibSSH2(const char *host, DEFAULT_VALUE(host, "localhost"); DEFAULT_VALUE(port, "22"); DEFAULT_VALUE(username, "root"); - DEFAULT_VALUE(netcatPath, "nc"); DEFAULT_VALUE(knownHostsVerify, "normal"); command = virNetClientSSHHelperCommand(netcatPath, socketPath); @@ -566,7 +568,6 @@ virNetClientPtr virNetClientNewLibssh(const char *host, DEFAULT_VALUE(host, "localhost"); DEFAULT_VALUE(port, "22"); DEFAULT_VALUE(username, "root"); - DEFAULT_VALUE(netcatPath, "nc"); DEFAULT_VALUE(knownHostsVerify, "normal"); command = virNetClientSSHHelperCommand(netcatPath, socketPath); -- 2.26.2
The remoteDriverTransport and remoteDriverMode enums are going to be needed by source files beyond the remote driver client. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/remote/meson.build | 1 + src/remote/remote_driver.c | 41 +----------------------------- src/remote/remote_sockets.c | 39 +++++++++++++++++++++++++++++ src/remote/remote_sockets.h | 50 +++++++++++++++++++++++++++++++++++++ 4 files changed, 91 insertions(+), 40 deletions(-) create mode 100644 src/remote/remote_sockets.c create mode 100644 src/remote/remote_sockets.h diff --git a/src/remote/meson.build b/src/remote/meson.build index 5983238a0a..91dd587cba 100644 --- a/src/remote/meson.build +++ b/src/remote/meson.build @@ -1,5 +1,6 @@ remote_driver_sources = [ 'remote_driver.c', + 'remote_sockets.c', ] remote_driver_generated = [] diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index f511a9bc33..b214632bdf 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -38,6 +38,7 @@ #include "virbuffer.h" #include "remote_driver.h" #include "remote_protocol.h" +#include "remote_sockets.h" #include "lxc_protocol.h" #include "qemu_protocol.h" #include "viralloc.h" @@ -54,46 +55,6 @@ VIR_LOG_INIT("remote.remote_driver"); -typedef enum { - REMOTE_DRIVER_TRANSPORT_TLS, - REMOTE_DRIVER_TRANSPORT_UNIX, - REMOTE_DRIVER_TRANSPORT_SSH, - REMOTE_DRIVER_TRANSPORT_LIBSSH2, - REMOTE_DRIVER_TRANSPORT_EXT, - REMOTE_DRIVER_TRANSPORT_TCP, - REMOTE_DRIVER_TRANSPORT_LIBSSH, - - REMOTE_DRIVER_TRANSPORT_LAST, -} remoteDriverTransport; - -VIR_ENUM_DECL(remoteDriverTransport); -VIR_ENUM_IMPL(remoteDriverTransport, - REMOTE_DRIVER_TRANSPORT_LAST, - "tls", - "unix", - "ssh", - "libssh2", - "ext", - "tcp", - "libssh"); - -typedef enum { - /* Try to figure out the "best" choice magically */ - REMOTE_DRIVER_MODE_AUTO, - /* Always use the legacy libvirtd */ - REMOTE_DRIVER_MODE_LEGACY, - /* Always use the per-driver virt*d daemons */ - REMOTE_DRIVER_MODE_DIRECT, - - REMOTE_DRIVER_MODE_LAST -} remoteDriverMode; - -VIR_ENUM_DECL(remoteDriverMode); -VIR_ENUM_IMPL(remoteDriverMode, - REMOTE_DRIVER_MODE_LAST, - "auto", - "legacy", - "direct"); #if SIZEOF_LONG < 8 # define HYPER_TO_TYPE(_type, _to, _from) \ diff --git a/src/remote/remote_sockets.c b/src/remote/remote_sockets.c new file mode 100644 index 0000000000..0662cbad14 --- /dev/null +++ b/src/remote/remote_sockets.c @@ -0,0 +1,39 @@ +/* + * remote_sockets.c: helpers for getting remote driver socket paths + * + * Copyright (C) 2007-2019 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>. + */ + +#include <config.h> + +#include "remote_sockets.h" + +VIR_ENUM_IMPL(remoteDriverTransport, + REMOTE_DRIVER_TRANSPORT_LAST, + "tls", + "unix", + "ssh", + "libssh2", + "ext", + "tcp", + "libssh"); + +VIR_ENUM_IMPL(remoteDriverMode, + REMOTE_DRIVER_MODE_LAST, + "auto", + "legacy", + "direct"); diff --git a/src/remote/remote_sockets.h b/src/remote/remote_sockets.h new file mode 100644 index 0000000000..1d4ae3f9c1 --- /dev/null +++ b/src/remote/remote_sockets.h @@ -0,0 +1,50 @@ +/* + * remote_sockets.h: helpers for getting remote driver socket paths + * + * Copyright (C) 2007-2020 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>. + */ + +#pragma once + +#include "virenum.h" + +typedef enum { + REMOTE_DRIVER_TRANSPORT_TLS, + REMOTE_DRIVER_TRANSPORT_UNIX, + REMOTE_DRIVER_TRANSPORT_SSH, + REMOTE_DRIVER_TRANSPORT_LIBSSH2, + REMOTE_DRIVER_TRANSPORT_EXT, + REMOTE_DRIVER_TRANSPORT_TCP, + REMOTE_DRIVER_TRANSPORT_LIBSSH, + + REMOTE_DRIVER_TRANSPORT_LAST, +} remoteDriverTransport; + +VIR_ENUM_DECL(remoteDriverTransport); + +typedef enum { + /* Try to figure out the "best" choice magically */ + REMOTE_DRIVER_MODE_AUTO, + /* Always use the legacy libvirtd */ + REMOTE_DRIVER_MODE_LEGACY, + /* Always use the per-driver virt*d daemons */ + REMOTE_DRIVER_MODE_DIRECT, + + REMOTE_DRIVER_MODE_LAST +} remoteDriverMode; + +VIR_ENUM_DECL(remoteDriverMode); -- 2.26.2
The remoteSplitURISCheme method will be needed by source files beyond the remote driver client. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/remote/remote_driver.c | 25 ------------------------- src/remote/remote_sockets.c | 28 ++++++++++++++++++++++++++++ src/remote/remote_sockets.h | 6 ++++++ 3 files changed, 34 insertions(+), 25 deletions(-) diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index b214632bdf..8952484b8e 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -165,31 +165,6 @@ static void make_nonnull_domain_snapshot(remote_nonnull_domain_snapshot *snapsho /*----------------------------------------------------------------------*/ /* Helper functions for remoteOpen. */ -static int remoteSplitURIScheme(virURIPtr uri, - char **driver, - char **transport) -{ - char *p = strchr(uri->scheme, '+'); - - *driver = *transport = NULL; - - if (p) - *driver = g_strndup(uri->scheme, p - uri->scheme); - else - *driver = g_strdup(uri->scheme); - - if (p) { - *transport = g_strdup(p + 1); - - p = *transport; - while (*p) { - *p = g_ascii_tolower(*p); - p++; - } - } - - return 0; -} static int diff --git a/src/remote/remote_sockets.c b/src/remote/remote_sockets.c index 0662cbad14..976124d0ed 100644 --- a/src/remote/remote_sockets.c +++ b/src/remote/remote_sockets.c @@ -37,3 +37,31 @@ VIR_ENUM_IMPL(remoteDriverMode, "auto", "legacy", "direct"); + + +int +remoteSplitURIScheme(virURIPtr uri, + char **driver, + char **transport) +{ + char *p = strchr(uri->scheme, '+'); + + *driver = *transport = NULL; + + if (p) + *driver = g_strndup(uri->scheme, p - uri->scheme); + else + *driver = g_strdup(uri->scheme); + + if (p) { + *transport = g_strdup(p + 1); + + p = *transport; + while (*p) { + *p = g_ascii_tolower(*p); + p++; + } + } + + return 0; +} diff --git a/src/remote/remote_sockets.h b/src/remote/remote_sockets.h index 1d4ae3f9c1..bef3cdada9 100644 --- a/src/remote/remote_sockets.h +++ b/src/remote/remote_sockets.h @@ -21,6 +21,7 @@ #pragma once #include "virenum.h" +#include "viruri.h" typedef enum { REMOTE_DRIVER_TRANSPORT_TLS, @@ -48,3 +49,8 @@ typedef enum { } remoteDriverMode; VIR_ENUM_DECL(remoteDriverMode); + +int +remoteSplitURIScheme(virURIPtr uri, + char **driver, + char **transport); -- 2.26.2
We delay converting the remote transport string to enum form until fairly late. As a result we're doing string comparisons when we could be just doing enum comparisons. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- po/POTFILES.in | 1 + src/remote/remote_driver.c | 51 ++++++++++--------------------------- src/remote/remote_sockets.c | 35 +++++++++++++++++++++---- src/remote/remote_sockets.h | 2 +- 4 files changed, 45 insertions(+), 44 deletions(-) diff --git a/po/POTFILES.in b/po/POTFILES.in index c5b43df7b5..c4197604ef 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -181,6 +181,7 @@ @SRCDIR@src/remote/remote_daemon_dispatch.c @SRCDIR@src/remote/remote_daemon_stream.c @SRCDIR@src/remote/remote_driver.c +@SRCDIR@src/remote/remote_sockets.c @SRCDIR@src/rpc/virkeepalive.c @SRCDIR@src/rpc/virnetclient.c @SRCDIR@src/rpc/virnetclientprogram.c diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index 8952484b8e..66d66c1284 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -863,12 +863,11 @@ static int doRemoteOpen(virConnectPtr conn, struct private_data *priv, const char *driver_str, - const char *transport_str, + remoteDriverTransport transport, virConnectAuthPtr auth G_GNUC_UNUSED, virConfPtr conf, unsigned int flags) { - int transport; #ifndef WIN32 g_autofree char *daemonPath = NULL; #endif @@ -903,34 +902,6 @@ doRemoteOpen(virConnectPtr conn, /* We handle *ALL* URIs here. The caller has rejected any * URIs we don't care about */ - if (conn->uri) { - if (!transport_str) { - if (conn->uri->server) - transport = REMOTE_DRIVER_TRANSPORT_TLS; - else - transport = REMOTE_DRIVER_TRANSPORT_UNIX; - } else { - if ((transport = remoteDriverTransportTypeFromString(transport_str)) < 0) { - virReportError(VIR_ERR_INVALID_ARG, "%s", - _("remote_open: transport in URL not recognised " - "(should be tls|unix|ssh|ext|tcp|libssh2|libssh)")); - return VIR_DRV_OPEN_ERROR; - } - - if (transport == REMOTE_DRIVER_TRANSPORT_UNIX && - conn->uri->server) { - virReportError(VIR_ERR_INVALID_ARG, - _("using unix socket and remote " - "server '%s' is not supported."), - conn->uri->server); - return VIR_DRV_OPEN_ERROR; - } - } - } else { - /* No URI, then must be probing so use UNIX socket */ - transport = REMOTE_DRIVER_TRANSPORT_UNIX; - } - /* Remote server defaults to "localhost" if not specified. */ if (conn->uri && conn->uri->port != 0) { port = g_strdup_printf("%d", conn->uri->port); @@ -1352,11 +1323,16 @@ remoteConnectOpen(virConnectPtr conn, int rflags = 0; const char *autostart = getenv("LIBVIRT_AUTOSTART"); char *driver = NULL; - char *transport = NULL; + remoteDriverTransport transport; + + if (conn->uri) { + if (remoteSplitURIScheme(conn->uri, &driver, &transport) < 0) + goto cleanup; + } else { + /* No URI, then must be probing so use UNIX socket */ + transport = REMOTE_DRIVER_TRANSPORT_UNIX; + } - if (conn->uri && - remoteSplitURIScheme(conn->uri, &driver, &transport) < 0) - goto cleanup; if (inside_daemon) { if (!conn->uri) { @@ -1398,12 +1374,12 @@ remoteConnectOpen(virConnectPtr conn, rflags |= VIR_DRV_OPEN_REMOTE_USER; /* - * Furthermore if no servername is given, and no +XXX - * transport is listed, or transport is unix, + * Furthermore if no servername is given, + * and the transport is unix, * and uid is unprivileged then auto-spawn a daemon. */ if (!conn->uri->server && - (transport == NULL || STREQ(transport, "unix")) && + (transport == REMOTE_DRIVER_TRANSPORT_UNIX) && (!autostart || STRNEQ(autostart, "0"))) { VIR_DEBUG("Try daemon autostart"); @@ -1438,7 +1414,6 @@ remoteConnectOpen(virConnectPtr conn, cleanup: VIR_FREE(driver); - VIR_FREE(transport); return ret; } diff --git a/src/remote/remote_sockets.c b/src/remote/remote_sockets.c index 976124d0ed..cdc0a00293 100644 --- a/src/remote/remote_sockets.c +++ b/src/remote/remote_sockets.c @@ -21,6 +21,9 @@ #include <config.h> #include "remote_sockets.h" +#include "virerror.h" + +#define VIR_FROM_THIS VIR_FROM_REMOTE VIR_ENUM_IMPL(remoteDriverTransport, REMOTE_DRIVER_TRANSPORT_LAST, @@ -42,25 +45,47 @@ VIR_ENUM_IMPL(remoteDriverMode, int remoteSplitURIScheme(virURIPtr uri, char **driver, - char **transport) + remoteDriverTransport *transport) { char *p = strchr(uri->scheme, '+'); - *driver = *transport = NULL; - if (p) *driver = g_strndup(uri->scheme, p - uri->scheme); else *driver = g_strdup(uri->scheme); if (p) { - *transport = g_strdup(p + 1); + g_autofree char *tmp = g_strdup(p + 1); + int val; - p = *transport; + p = tmp; while (*p) { *p = g_ascii_tolower(*p); p++; } + + if ((val = remoteDriverTransportTypeFromString(tmp)) < 0) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("remote_open: transport in URL not recognised " + "(should be tls|unix|ssh|ext|tcp|libssh2|libssh)")); + return -1; + } + + if (val == REMOTE_DRIVER_TRANSPORT_UNIX && + uri->server) { + virReportError(VIR_ERR_INVALID_ARG, + _("using unix socket and remote " + "server '%s' is not supported."), + uri->server); + return -1; + } + + *transport = val; + } else { + if (uri->server) + *transport = REMOTE_DRIVER_TRANSPORT_TLS; + else + *transport = REMOTE_DRIVER_TRANSPORT_UNIX; } return 0; diff --git a/src/remote/remote_sockets.h b/src/remote/remote_sockets.h index bef3cdada9..ade3feab88 100644 --- a/src/remote/remote_sockets.h +++ b/src/remote/remote_sockets.h @@ -53,4 +53,4 @@ VIR_ENUM_DECL(remoteDriverMode); int remoteSplitURIScheme(virURIPtr uri, char **driver, - char **transport); + remoteDriverTransport *transport); -- 2.26.2
The remoteGetUNIXSocketHelper method will be needed by source files beyond the remote driver client. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/remote/remote_driver.c | 129 +--------------------------------- src/remote/remote_sockets.c | 134 ++++++++++++++++++++++++++++++++++++ src/remote/remote_sockets.h | 8 +++ 3 files changed, 145 insertions(+), 126 deletions(-) diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index 66d66c1284..6ab0d67854 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -697,131 +697,6 @@ remoteConnectSupportsFeatureUnlocked(virConnectPtr conn, } -static char * -remoteGetUNIXSocketHelper(remoteDriverTransport transport, - const char *sock_prefix, - unsigned int flags) -{ - char *sockname = NULL; - g_autofree char *userdir = NULL; - - if (flags & VIR_DRV_OPEN_REMOTE_USER) { - if (transport != REMOTE_DRIVER_TRANSPORT_UNIX) { - virReportError(VIR_ERR_OPERATION_UNSUPPORTED, - _("Connecting to session instance without " - "socket path is not supported by the %s " - "transport"), - remoteDriverTransportTypeToString(transport)); - return NULL; - } - userdir = virGetUserRuntimeDirectory(); - - sockname = g_strdup_printf("%s/%s-sock", userdir, sock_prefix); - } else { - /* Intentionally do *NOT* use RUNSTATEDIR here. We might - * be connecting to a remote machine, and cannot assume - * the remote host has /run. The converse is ok though, - * any machine with /run will have a /var/run symlink. - * The portable option is to thus use $LOCALSTATEDIR/run - */ - sockname = g_strdup_printf("%s/run/libvirt/%s-%s", LOCALSTATEDIR, - sock_prefix, - flags & VIR_DRV_OPEN_REMOTE_RO ? "sock-ro" : "sock"); - } - - VIR_DEBUG("Built UNIX sockname %s for transport %s prefix %s flags=0x%x", - sockname, remoteDriverTransportTypeToString(transport), - sock_prefix, flags); - return sockname; -} - - -static char * -remoteGetUNIXSocket(remoteDriverTransport transport, - remoteDriverMode mode, - const char *driver, - char **daemon, - unsigned int flags) -{ - char *sock_name = NULL; - g_autofree char *direct_daemon = NULL; - g_autofree char *legacy_daemon = NULL; - g_autofree char *direct_sock_name = NULL; - g_autofree char *legacy_sock_name = NULL; - - if (driver) - direct_daemon = g_strdup_printf("virt%sd", driver); - - legacy_daemon = g_strdup("libvirtd"); - - if (driver && - !(direct_sock_name = remoteGetUNIXSocketHelper(transport, direct_daemon, flags))) - return NULL; - - if (!(legacy_sock_name = remoteGetUNIXSocketHelper(transport, "libvirt", flags))) - return NULL; - - if (mode == REMOTE_DRIVER_MODE_AUTO) { - if (transport == REMOTE_DRIVER_TRANSPORT_UNIX) { - if (direct_sock_name && virFileExists(direct_sock_name)) { - mode = REMOTE_DRIVER_MODE_DIRECT; - } else if (virFileExists(legacy_sock_name)) { - mode = REMOTE_DRIVER_MODE_LEGACY; - } else if (driver) { - /* - * This constant comes from the configure script and - * maps to either the direct or legacy mode constant - */ - mode = REMOTE_DRIVER_MODE_DEFAULT; - } else { - mode = REMOTE_DRIVER_MODE_LEGACY; - } - } else { - mode = REMOTE_DRIVER_MODE_LEGACY; - } - } - - switch ((remoteDriverMode)mode) { - case REMOTE_DRIVER_MODE_LEGACY: - sock_name = g_steal_pointer(&legacy_sock_name); - *daemon = g_steal_pointer(&legacy_daemon); - break; - - case REMOTE_DRIVER_MODE_DIRECT: - if (transport != REMOTE_DRIVER_TRANSPORT_UNIX) { - virReportError(VIR_ERR_OPERATION_UNSUPPORTED, - _("Cannot use direct socket mode for %s transport"), - remoteDriverTransportTypeToString(transport)); - return NULL; - } - - if (!direct_sock_name) { - virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s", - _("Cannot use direct socket mode if no URI is set")); - return NULL; - } - - sock_name = g_steal_pointer(&direct_sock_name); - *daemon = g_steal_pointer(&direct_daemon); - break; - - case REMOTE_DRIVER_MODE_AUTO: - case REMOTE_DRIVER_MODE_LAST: - default: - virReportEnumRangeError(remoteDriverMode, mode); - return NULL; - } - - VIR_DEBUG("Chosen UNIX sockname %s daemon %s " - "for mode %s transport %s flags=0x%x", - sock_name, NULLSTR(*daemon), - remoteDriverModeTypeToString(mode), - remoteDriverTransportTypeToString(transport), - flags); - return sock_name; -} - - #ifndef WIN32 static const char * remoteGetDaemonPathEnv(void) @@ -1015,7 +890,9 @@ doRemoteOpen(virConnectPtr conn, case REMOTE_DRIVER_TRANSPORT_LIBSSH2: if (!sockname && !(sockname = remoteGetUNIXSocket(transport, mode, driver_str, - &daemon_name, flags))) + flags & VIR_DRV_OPEN_REMOTE_RO, + flags & VIR_DRV_OPEN_REMOTE_USER, + &daemon_name))) goto failed; break; diff --git a/src/remote/remote_sockets.c b/src/remote/remote_sockets.c index cdc0a00293..28e02e24d5 100644 --- a/src/remote/remote_sockets.c +++ b/src/remote/remote_sockets.c @@ -22,9 +22,15 @@ #include "remote_sockets.h" #include "virerror.h" +#include "virlog.h" +#include "virfile.h" +#include "virutil.h" +#include "configmake.h" #define VIR_FROM_THIS VIR_FROM_REMOTE +VIR_LOG_INIT("remote.remote_sockets"); + VIR_ENUM_IMPL(remoteDriverTransport, REMOTE_DRIVER_TRANSPORT_LAST, "tls", @@ -90,3 +96,131 @@ remoteSplitURIScheme(virURIPtr uri, return 0; } + + +static char * +remoteGetUNIXSocketHelper(remoteDriverTransport transport, + const char *sock_prefix, + bool ro, + bool session) +{ + char *sockname = NULL; + g_autofree char *userdir = NULL; + + if (session) { + if (transport != REMOTE_DRIVER_TRANSPORT_UNIX) { + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, + _("Connecting to session instance without " + "socket path is not supported by the %s " + "transport"), + remoteDriverTransportTypeToString(transport)); + return NULL; + } + userdir = virGetUserRuntimeDirectory(); + + sockname = g_strdup_printf("%s/%s-sock", userdir, sock_prefix); + } else { + /* Intentionally do *NOT* use RUNSTATEDIR here. We might + * be connecting to a remote machine, and cannot assume + * the remote host has /run. The converse is ok though, + * any machine with /run will have a /var/run symlink. + * The portable option is to thus use $LOCALSTATEDIR/run + */ + sockname = g_strdup_printf("%s/run/libvirt/%s-%s", LOCALSTATEDIR, + sock_prefix, + ro ? "sock-ro" : "sock"); + } + + VIR_DEBUG("Built UNIX sockname=%s for transport=%s " + "prefix=%s ro=%d session=%d", + sockname, remoteDriverTransportTypeToString(transport), + sock_prefix, ro, session); + return sockname; +} + + +char * +remoteGetUNIXSocket(remoteDriverTransport transport, + remoteDriverMode mode, + const char *driver, + bool ro, + bool session, + char **daemon) +{ + char *sock_name = NULL; + g_autofree char *direct_daemon = NULL; + g_autofree char *legacy_daemon = NULL; + g_autofree char *direct_sock_name = NULL; + g_autofree char *legacy_sock_name = NULL; + + if (driver) + direct_daemon = g_strdup_printf("virt%sd", driver); + + legacy_daemon = g_strdup("libvirtd"); + + if (driver && + !(direct_sock_name = remoteGetUNIXSocketHelper(transport, direct_daemon, ro, session))) + return NULL; + + if (!(legacy_sock_name = remoteGetUNIXSocketHelper(transport, "libvirt", ro, session))) + return NULL; + + if (mode == REMOTE_DRIVER_MODE_AUTO) { + if (transport == REMOTE_DRIVER_TRANSPORT_UNIX) { + if (direct_sock_name && virFileExists(direct_sock_name)) { + mode = REMOTE_DRIVER_MODE_DIRECT; + } else if (virFileExists(legacy_sock_name)) { + mode = REMOTE_DRIVER_MODE_LEGACY; + } else if (driver) { + /* + * This constant comes from the configure script and + * maps to either the direct or legacy mode constant + */ + mode = REMOTE_DRIVER_MODE_DEFAULT; + } else { + mode = REMOTE_DRIVER_MODE_LEGACY; + } + } else { + mode = REMOTE_DRIVER_MODE_LEGACY; + } + } + + switch ((remoteDriverMode)mode) { + case REMOTE_DRIVER_MODE_LEGACY: + sock_name = g_steal_pointer(&legacy_sock_name); + *daemon = g_steal_pointer(&legacy_daemon); + break; + + case REMOTE_DRIVER_MODE_DIRECT: + if (transport != REMOTE_DRIVER_TRANSPORT_UNIX) { + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, + _("Cannot use direct socket mode for %s transport"), + remoteDriverTransportTypeToString(transport)); + return NULL; + } + + if (!direct_sock_name) { + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s", + _("Cannot use direct socket mode if no URI is set")); + return NULL; + } + + sock_name = g_steal_pointer(&direct_sock_name); + *daemon = g_steal_pointer(&direct_daemon); + break; + + case REMOTE_DRIVER_MODE_AUTO: + case REMOTE_DRIVER_MODE_LAST: + default: + virReportEnumRangeError(remoteDriverMode, mode); + return NULL; + } + + VIR_DEBUG("Chosen UNIX sockname=%s daemon=%s " + "for mode=%s transport=%s ro=%d session=%d", + sock_name, NULLSTR(*daemon), + remoteDriverModeTypeToString(mode), + remoteDriverTransportTypeToString(transport), + ro, session); + return sock_name; +} diff --git a/src/remote/remote_sockets.h b/src/remote/remote_sockets.h index ade3feab88..64055f3d44 100644 --- a/src/remote/remote_sockets.h +++ b/src/remote/remote_sockets.h @@ -54,3 +54,11 @@ int remoteSplitURIScheme(virURIPtr uri, char **driver, remoteDriverTransport *transport); + +char * +remoteGetUNIXSocket(remoteDriverTransport transport, + remoteDriverMode mode, + const char *driver, + bool ro, + bool session, + char **daemon); -- 2.26.2
We'll shortly want to reuse code for determining whether to connect to the system or session daemon from places outside the remote driver client. Pulling it out into a self contained function facilitates reuse. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/remote/remote_driver.c | 51 ++++---------------------------- src/remote/remote_sockets.c | 59 +++++++++++++++++++++++++++++++++++++ src/remote/remote_sockets.h | 6 ++++ 3 files changed, 71 insertions(+), 45 deletions(-) diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index 6ab0d67854..df10cfaef6 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -1198,7 +1198,8 @@ remoteConnectOpen(virConnectPtr conn, struct private_data *priv; int ret = VIR_DRV_OPEN_ERROR; int rflags = 0; - const char *autostart = getenv("LIBVIRT_AUTOSTART"); + bool user; + bool autostart; char *driver = NULL; remoteDriverTransport transport; @@ -1233,51 +1234,11 @@ remoteConnectOpen(virConnectPtr conn, if (flags & VIR_CONNECT_RO) rflags |= VIR_DRV_OPEN_REMOTE_RO; - /* - * User session daemon is used for - * - * - Any URI with /session suffix - * - Test driver, if a protocol is given - * - * provided we are running non-root - */ - if (conn->uri && - conn->uri->path && - conn->uri->scheme && - (STREQ(conn->uri->path, "/session") || - STRPREFIX(conn->uri->scheme, "test+")) && - geteuid() > 0) { - VIR_DEBUG("User session daemon required"); + remoteGetURIDaemonInfo(conn->uri, transport, &user, &autostart); + if (user) rflags |= VIR_DRV_OPEN_REMOTE_USER; - - /* - * Furthermore if no servername is given, - * and the transport is unix, - * and uid is unprivileged then auto-spawn a daemon. - */ - if (!conn->uri->server && - (transport == REMOTE_DRIVER_TRANSPORT_UNIX) && - (!autostart || - STRNEQ(autostart, "0"))) { - VIR_DEBUG("Try daemon autostart"); - rflags |= VIR_DRV_OPEN_REMOTE_AUTOSTART; - } - } - - /* - * If URI is NULL, then do a UNIX connection possibly auto-spawning - * unprivileged server and probe remote server for URI. - */ - if (!conn->uri) { - VIR_DEBUG("Auto-probe remote URI"); - if (geteuid() > 0) { - VIR_DEBUG("Auto-spawn user daemon instance"); - rflags |= VIR_DRV_OPEN_REMOTE_USER; - if (!autostart || - STRNEQ(autostart, "0")) - rflags |= VIR_DRV_OPEN_REMOTE_AUTOSTART; - } - } + if (autostart) + rflags |= VIR_DRV_OPEN_REMOTE_AUTOSTART; ret = doRemoteOpen(conn, priv, driver, transport, auth, conf, rflags); if (ret != VIR_DRV_OPEN_SUCCESS) { diff --git a/src/remote/remote_sockets.c b/src/remote/remote_sockets.c index 28e02e24d5..854775f401 100644 --- a/src/remote/remote_sockets.c +++ b/src/remote/remote_sockets.c @@ -224,3 +224,62 @@ remoteGetUNIXSocket(remoteDriverTransport transport, ro, session); return sock_name; } + + +void +remoteGetURIDaemonInfo(virURIPtr uri, + remoteDriverTransport transport, + bool *session, + bool *autostart) +{ + const char *autostart_str = getenv("LIBVIRT_AUTOSTART"); + + *session = false; + *autostart = false; + + /* + * User session daemon is used for + * + * - Any URI with /session suffix + * - Test driver, if a protocol is given + * + * provided we are running non-root + */ + if (uri && + uri->path && + uri->scheme && + (STREQ(uri->path, "/session") || + STRPREFIX(uri->scheme, "test+")) && + geteuid() > 0) { + VIR_DEBUG("User session daemon required"); + *session = true; + + /* + * Furthermore if no servername is given, + * and the transport is unix, + * and uid is unprivileged then auto-spawn a daemon. + */ + if (!uri->server && + (transport == REMOTE_DRIVER_TRANSPORT_UNIX) && + (!autostart_str || + STRNEQ(autostart_str, "0"))) { + VIR_DEBUG("Try daemon autostart"); + *autostart = true; + } + } + + /* + * If URI is NULL, then do a UNIX connection possibly auto-spawning + * unprivileged server and probe remote server for URI. + */ + if (!uri) { + VIR_DEBUG("Auto-probe remote URI"); + if (geteuid() > 0) { + VIR_DEBUG("Auto-spawn user daemon instance"); + *session = true; + if (!autostart_str || + STRNEQ(autostart_str, "0")) + *autostart = true; + } + } +} diff --git a/src/remote/remote_sockets.h b/src/remote/remote_sockets.h index 64055f3d44..7526752835 100644 --- a/src/remote/remote_sockets.h +++ b/src/remote/remote_sockets.h @@ -62,3 +62,9 @@ remoteGetUNIXSocket(remoteDriverTransport transport, bool ro, bool session, char **daemon); + +void +remoteGetURIDaemonInfo(virURIPtr uri, + remoteDriverTransport transport, + bool *session, + bool *autostart); -- 2.26.2
When accessing libvirtd over a SSH tunnel, the remote driver needs a way to proxy the SSH input/output stream to a suitable libvirt daemon. Tihs is currently done by spawning netcat, pointing it to the libvirtd socket path. This is problematic for a number of reasons: - The socket path varies according to the --prefix chosen at build time. The remote client is seeing the local prefix, but what we need is the remote prefix - The socket path varies according to remote env variables, such as the XDG_RUNTIME_DIR location. Again we see the local XDG_RUNTIME_DIR value, but what we need is the remote value (if any) - The remote driver doesn't know whether it must connect to the legacy libvirtd or the modular daemons, so must always assume legacy libvirtd for back-compat. This means we'll always end up using the virtproxyd daemon adding an extra hop in the RPC layer. - We can not able to autospawn the libvirtd daemon for session mode access To address these problems this patch introduces the 'virtd-ssh-helper' program which takes the URI for the remote driver as a CLI parameter. It then figures out which daemon to connect to and its socket path, using the same code that the remote driver client would on the remote host's build of libvirt. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- build-aux/syntax-check.mk | 2 +- libvirt.spec.in | 2 + po/POTFILES.in | 1 + src/remote/meson.build | 17 ++ src/remote/remote_ssh_helper.c | 425 +++++++++++++++++++++++++++++++++ src/rpc/virnetsocket.h | 1 + 6 files changed, 447 insertions(+), 1 deletion(-) create mode 100644 src/remote/remote_ssh_helper.c diff --git a/build-aux/syntax-check.mk b/build-aux/syntax-check.mk index 6eb59cf90e..151f7a4767 100644 --- a/build-aux/syntax-check.mk +++ b/build-aux/syntax-check.mk @@ -1864,7 +1864,7 @@ sc_group-qemu-caps: # List all syntax-check exemptions: exclude_file_name_regexp--sc_avoid_strcase = ^tools/vsh\.h$$ -_src1=libvirt-stream|qemu/qemu_monitor|util/vir(command|file|fdstream)|rpc/virnetsocket|lxc/lxc_controller|locking/lock_daemon|logging/log_daemon +_src1=libvirt-stream|qemu/qemu_monitor|util/vir(command|file|fdstream)|rpc/virnetsocket|lxc/lxc_controller|locking/lock_daemon|logging/log_daemon|remote/remote_ssh_helper _test1=shunloadtest|virnettlscontexttest|virnettlssessiontest|vircgroupmock|commandhelper exclude_file_name_regexp--sc_avoid_write = \ ^(src/($(_src1))|tools/virsh-console|tests/($(_test1)))\.c$$ diff --git a/libvirt.spec.in b/libvirt.spec.in index e64cfdb561..35125e4f8e 100644 --- a/libvirt.spec.in +++ b/libvirt.spec.in @@ -1561,6 +1561,8 @@ exit 0 %attr(0755, root, root) %{_libexecdir}/libvirt_iohelper +%attr(0755, root, root) %{_bindir}/virt-ssh-helper + %attr(0755, root, root) %{_sbindir}/libvirtd %attr(0755, root, root) %{_sbindir}/virtproxyd %attr(0755, root, root) %{_sbindir}/virtlogd diff --git a/po/POTFILES.in b/po/POTFILES.in index c4197604ef..1ab94972c7 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -182,6 +182,7 @@ @SRCDIR@src/remote/remote_daemon_stream.c @SRCDIR@src/remote/remote_driver.c @SRCDIR@src/remote/remote_sockets.c +@SRCDIR@src/remote/remote_ssh_helper.c @SRCDIR@src/rpc/virkeepalive.c @SRCDIR@src/rpc/virnetclient.c @SRCDIR@src/rpc/virnetclientprogram.c diff --git a/src/remote/meson.build b/src/remote/meson.build index 91dd587cba..9ad2f6ab1c 100644 --- a/src/remote/meson.build +++ b/src/remote/meson.build @@ -51,6 +51,15 @@ remote_daemon_sources = files( remote_daemon_generated = [] +virt_ssh_helper_sources = files( + 'remote_sockets.c', + 'remote_ssh_helper.c', +) + +virt_ssh_helper_dep = [ + src_dep, +] + foreach name : [ 'remote', 'qemu', 'lxc' ] protocol_x = '@0@_protocol.x'.format(name) dispatch_h = '@0@_daemon_dispatch_stubs.h'.format(name) @@ -278,6 +287,14 @@ if conf.has('WITH_REMOTE') rename: [ '50-libvirt.rules' ], ) endif + + virt_helpers += { + 'name': 'virt-ssh-helper', + 'sources': [ + virt_ssh_helper_sources + ], + 'install_dir': bindir, + } endif endif diff --git a/src/remote/remote_ssh_helper.c b/src/remote/remote_ssh_helper.c new file mode 100644 index 0000000000..0da55c1d1f --- /dev/null +++ b/src/remote/remote_ssh_helper.c @@ -0,0 +1,425 @@ +/* + * remote_ssh_helper.c: a netcat replacement for proxying ssh tunnel to daemon + * + * Copyright (C) 2020 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>. + */ + +#include <config.h> + +#include <unistd.h> + +#include "rpc/virnetsocket.h" +#include "viralloc.h" +#include "virlog.h" +#include "virgettext.h" +#include "virfile.h" + +#include "remote_sockets.h" + +#define VIR_FROM_THIS VIR_FROM_REMOTE + +VIR_LOG_INIT("remote.remote_ssh_helper"); + +struct virRemoteSSHHelperBuffer { + size_t length; + size_t offset; + char *data; +}; + +typedef struct virRemoteSSHHelper virRemoteSSHHelper; +typedef virRemoteSSHHelper *virRemoteSSHHelperPtr; +struct virRemoteSSHHelper { + bool quit; + virNetSocketPtr sock; + int stdinWatch; + int stdoutWatch; + + struct virRemoteSSHHelperBuffer sockToTerminal; + struct virRemoteSSHHelperBuffer terminalToSock; +}; + + +static void +virRemoteSSHHelperShutdown(virRemoteSSHHelperPtr proxy) +{ + if (proxy->sock) { + virNetSocketRemoveIOCallback(proxy->sock); + virNetSocketClose(proxy->sock); + virObjectUnref(proxy->sock); + proxy->sock = NULL; + } + VIR_FREE(proxy->sockToTerminal.data); + VIR_FREE(proxy->terminalToSock.data); + if (proxy->stdinWatch != -1) + virEventRemoveHandle(proxy->stdinWatch); + if (proxy->stdoutWatch != -1) + virEventRemoveHandle(proxy->stdoutWatch); + proxy->stdinWatch = -1; + proxy->stdoutWatch = -1; + if (!proxy->quit) + proxy->quit = true; +} + + +static void +virRemoteSSHHelperEventOnSocket(virNetSocketPtr sock, + int events, + void *opaque) +{ + virRemoteSSHHelperPtr proxy = opaque; + + /* we got late event after proxy was shutdown */ + if (!proxy->sock) + return; + + if (events & VIR_EVENT_HANDLE_READABLE) { + size_t avail = proxy->sockToTerminal.length - + proxy->sockToTerminal.offset; + int got; + + if (avail < 1024) { + if (VIR_REALLOC_N(proxy->sockToTerminal.data, + proxy->sockToTerminal.length + 1024) < 0) { + virRemoteSSHHelperShutdown(proxy); + return; + } + proxy->sockToTerminal.length += 1024; + avail += 1024; + } + + got = virNetSocketRead(sock, + proxy->sockToTerminal.data + + proxy->sockToTerminal.offset, + avail); + if (got == -2) + return; /* blocking */ + if (got == 0) { + VIR_DEBUG("EOF on socket, shutting down"); + virRemoteSSHHelperShutdown(proxy); + return; + } + if (got < 0) { + virRemoteSSHHelperShutdown(proxy); + return; + } + proxy->sockToTerminal.offset += got; + if (proxy->sockToTerminal.offset) + virEventUpdateHandle(proxy->stdoutWatch, + VIR_EVENT_HANDLE_WRITABLE); + } + + if (events & VIR_EVENT_HANDLE_WRITABLE && + proxy->terminalToSock.offset) { + ssize_t done; + size_t avail; + done = virNetSocketWrite(proxy->sock, + proxy->terminalToSock.data, + proxy->terminalToSock.offset); + if (done == -2) + return; /* blocking */ + if (done < 0) { + virRemoteSSHHelperShutdown(proxy); + return; + } + memmove(proxy->terminalToSock.data, + proxy->terminalToSock.data + done, + proxy->terminalToSock.offset - done); + proxy->terminalToSock.offset -= done; + + avail = proxy->terminalToSock.length - proxy->terminalToSock.offset; + if (avail > 1024) { + ignore_value(VIR_REALLOC_N(proxy->terminalToSock.data, + proxy->terminalToSock.offset + 1024)); + proxy->terminalToSock.length = proxy->terminalToSock.offset + 1024; + } + } + if (!proxy->terminalToSock.offset) + virNetSocketUpdateIOCallback(proxy->sock, + VIR_EVENT_HANDLE_READABLE); + + if (events & VIR_EVENT_HANDLE_ERROR || + events & VIR_EVENT_HANDLE_HANGUP) { + virRemoteSSHHelperShutdown(proxy); + } +} + + +static void +virRemoteSSHHelperEventOnStdin(int watch G_GNUC_UNUSED, + int fd G_GNUC_UNUSED, + int events, + void *opaque) +{ + virRemoteSSHHelperPtr proxy = opaque; + + /* we got late event after console was shutdown */ + if (!proxy->sock) + return; + + if (events & VIR_EVENT_HANDLE_READABLE) { + size_t avail = proxy->terminalToSock.length - + proxy->terminalToSock.offset; + int got; + + if (avail < 1024) { + if (VIR_REALLOC_N(proxy->terminalToSock.data, + proxy->terminalToSock.length + 1024) < 0) { + virRemoteSSHHelperShutdown(proxy); + return; + } + proxy->terminalToSock.length += 1024; + avail += 1024; + } + + got = read(fd, + proxy->terminalToSock.data + + proxy->terminalToSock.offset, + avail); + if (got < 0) { + if (errno != EAGAIN) { + virReportSystemError(errno, "%s", _("cannot read from stdin")); + virRemoteSSHHelperShutdown(proxy); + } + return; + } + if (got == 0) { + VIR_DEBUG("EOF on stdin, shutting down"); + virRemoteSSHHelperShutdown(proxy); + return; + } + + proxy->terminalToSock.offset += got; + if (proxy->terminalToSock.offset) + virNetSocketUpdateIOCallback(proxy->sock, + VIR_EVENT_HANDLE_READABLE | + VIR_EVENT_HANDLE_WRITABLE); + } + + if (events & VIR_EVENT_HANDLE_ERROR) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("IO error on stdin")); + virRemoteSSHHelperShutdown(proxy); + return; + } + + if (events & VIR_EVENT_HANDLE_HANGUP) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("EOF on stdin")); + virRemoteSSHHelperShutdown(proxy); + return; + } +} + + +static void +virRemoteSSHHelperEventOnStdout(int watch G_GNUC_UNUSED, + int fd, + int events, + void *opaque) +{ + virRemoteSSHHelperPtr proxy = opaque; + + /* we got late event after console was shutdown */ + if (!proxy->sock) + return; + + if (events & VIR_EVENT_HANDLE_WRITABLE && + proxy->sockToTerminal.offset) { + ssize_t done; + size_t avail; + done = write(fd, + proxy->sockToTerminal.data, + proxy->sockToTerminal.offset); + if (done < 0) { + if (errno != EAGAIN) { + virReportSystemError(errno, "%s", _("cannot write to stdout")); + virRemoteSSHHelperShutdown(proxy); + } + return; + } + memmove(proxy->sockToTerminal.data, + proxy->sockToTerminal.data + done, + proxy->sockToTerminal.offset - done); + proxy->sockToTerminal.offset -= done; + + avail = proxy->sockToTerminal.length - proxy->sockToTerminal.offset; + if (avail > 1024) { + ignore_value(VIR_REALLOC_N(proxy->sockToTerminal.data, + proxy->sockToTerminal.offset + 1024)); + proxy->sockToTerminal.length = proxy->sockToTerminal.offset + 1024; + } + } + + if (!proxy->sockToTerminal.offset) + virEventUpdateHandle(proxy->stdoutWatch, 0); + + if (events & VIR_EVENT_HANDLE_ERROR) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("IO error stdout")); + virRemoteSSHHelperShutdown(proxy); + return; + } + + if (events & VIR_EVENT_HANDLE_HANGUP) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("EOF on stdout")); + virRemoteSSHHelperShutdown(proxy); + return; + } +} + + +static int +virRemoteSSHHelperRun(virNetSocketPtr sock) +{ + int ret = -1; + virRemoteSSHHelper proxy = { + .sock = sock, + .stdinWatch = -1, + .stdoutWatch = -1, + }; + + virEventRegisterDefaultImpl(); + + if ((proxy.stdinWatch = virEventAddHandle(STDIN_FILENO, + VIR_EVENT_HANDLE_READABLE, + virRemoteSSHHelperEventOnStdin, + &proxy, + NULL)) < 0) + goto cleanup; + + if ((proxy.stdoutWatch = virEventAddHandle(STDOUT_FILENO, + 0, + virRemoteSSHHelperEventOnStdout, + &proxy, + NULL)) < 0) + goto cleanup; + + if (virNetSocketAddIOCallback(proxy.sock, + VIR_EVENT_HANDLE_READABLE, + virRemoteSSHHelperEventOnSocket, + &proxy, + NULL) < 0) + goto cleanup; + + while (!proxy.quit) + virEventRunDefaultImpl(); + + if (virGetLastErrorCode() != VIR_ERR_OK) + goto cleanup; + + ret = 0; + cleanup: + if (proxy.stdinWatch != -1) + virEventRemoveHandle(proxy.stdinWatch); + if (proxy.stdoutWatch != -1) + virEventRemoveHandle(proxy.stdoutWatch); + return ret; +} + +int main(int argc, char **argv) +{ + const char *uri_str = NULL; + g_autoptr(virURI) uri = NULL; + g_autofree char *driver = NULL; + remoteDriverTransport transport; + bool user = false; + bool autostart = false; + gboolean version = false; + gboolean readonly = false; + g_autofree char *sock_path = NULL; + g_autofree char *daemon_name = NULL; + g_autoptr(virNetSocket) sock = NULL; + GError *error = NULL; + g_autoptr(GOptionContext) context = NULL; + GOptionEntry entries[] = { + { "readonly", 'r', 0, G_OPTION_ARG_NONE, &readonly, "Connect read-only", NULL }, + { "version", 'V', 0, G_OPTION_ARG_NONE, &version, "Display version information", NULL }, + { NULL, '\0', 0, 0, NULL, NULL, NULL } + }; + + context = g_option_context_new("- libvirt socket proxy"); + g_option_context_add_main_entries(context, entries, PACKAGE); + if (!g_option_context_parse(context, &argc, &argv, &error)) { + g_printerr(_("option parsing failed: %s\n"), error->message); + exit(EXIT_FAILURE); + } + + if (version) { + g_print("%s (%s) %s\n", argv[0], PACKAGE_NAME, PACKAGE_VERSION); + exit(EXIT_SUCCESS); + } + + virSetErrorFunc(NULL, NULL); + virSetErrorLogPriorityFunc(NULL); + + if (virGettextInitialize() < 0 || + virErrorInitialize() < 0) { + g_printerr(_("%s: initialization failed\n"), argv[0]); + exit(EXIT_FAILURE); + } + + virFileActivateDirOverrideForProg(argv[0]); + + /* Initialize the log system */ + virLogSetFromEnv(); + + if (optind != (argc - 1)) { + g_printerr("%s: expected a URI\n", argv[0]); + exit(EXIT_FAILURE); + } + + uri_str = argv[optind]; + VIR_DEBUG("Using URI %s", uri_str); + + if (!(uri = virURIParse(uri_str))) { + g_printerr(("%s: cannot parse '%s': %s\n"), + argv[0], uri_str, virGetLastErrorMessage()); + exit(EXIT_FAILURE); + } + + if (remoteSplitURIScheme(uri, &driver, &transport) < 0) { + g_printerr(_("%s: cannot parse URI transport '%s': %s\n"), + argv[0], uri_str, virGetLastErrorMessage()); + exit(EXIT_FAILURE); + } + + if (transport != REMOTE_DRIVER_TRANSPORT_UNIX) { + g_printerr(_("%s: unexpected URI transport '%s'\n"), + argv[0], uri_str); + exit(EXIT_FAILURE); + } + + remoteGetURIDaemonInfo(uri, transport, &user, &autostart); + + sock_path = remoteGetUNIXSocket(transport, + REMOTE_DRIVER_MODE_AUTO, + driver, + !!readonly, + user, + &daemon_name); + + if (virNetSocketNewConnectUNIX(sock_path, autostart, daemon_name, &sock) < 0) { + g_printerr(_("%s: cannot connect to '%s': %s\n"), + argv[0], sock_path, virGetLastErrorMessage()); + exit(EXIT_FAILURE); + } + + if (virRemoteSSHHelperRun(sock) < 0) { + g_printerr(_("%s: could not proxy traffic: %s\n"), + argv[0], virGetLastErrorMessage()); + exit(EXIT_FAILURE); + } + + exit(EXIT_SUCCESS); +} diff --git a/src/rpc/virnetsocket.h b/src/rpc/virnetsocket.h index d39b270480..3996d264fb 100644 --- a/src/rpc/virnetsocket.h +++ b/src/rpc/virnetsocket.h @@ -34,6 +34,7 @@ typedef struct _virNetSocket virNetSocket; typedef virNetSocket *virNetSocketPtr; +G_DEFINE_AUTOPTR_CLEANUP_FUNC(virNetSocket, virObjectUnref); typedef void (*virNetSocketIOFunc)(virNetSocketPtr sock, int events, -- 2.26.2
Switch keyfile and netcat parameters, since the netcat path and socket path are a logical pair that belong together. This patches the other constructors. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/remote/remote_driver.c | 2 +- src/rpc/virnetclient.c | 2 +- src/rpc/virnetclient.h | 4 ++-- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index df10cfaef6..d56f4b7260 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -1010,8 +1010,8 @@ doRemoteOpen(virConnectPtr conn, username, !tty, !verify, - netcat, keyfile, + netcat, sockname))) goto failed; diff --git a/src/rpc/virnetclient.c b/src/rpc/virnetclient.c index f65cda0d7f..72ece28f59 100644 --- a/src/rpc/virnetclient.c +++ b/src/rpc/virnetclient.c @@ -444,8 +444,8 @@ virNetClientPtr virNetClientNewSSH(const char *nodename, const char *username, bool noTTY, bool noVerify, - const char *netcatPath, const char *keyfile, + const char *netcatPath, const char *socketPath) { virNetSocketPtr sock; diff --git a/src/rpc/virnetclient.h b/src/rpc/virnetclient.h index 0005de46f3..6fdc370083 100644 --- a/src/rpc/virnetclient.h +++ b/src/rpc/virnetclient.h @@ -48,9 +48,9 @@ virNetClientPtr virNetClientNewSSH(const char *nodename, const char *username, bool noTTY, bool noVerify, - const char *netcat, const char *keyfile, - const char *path); + const char *netcat, + const char *socketPath); virNetClientPtr virNetClientNewLibSSH2(const char *host, const char *port, -- 2.26.2
This wires up support for using the new virt-ssh-helper binary with the ssh, libssh and libssh2 protocols. The new binary will be used preferentially if it is available in $PATH, otherwise we fall back to traditional netcat. The "proxy" URI parameter can be used to force use of netcat e.g. qemu+ssh://host/system?proxy=netcat or the disable fallback e.g. qemu+ssh://host/system?proxy=native With use of virt-ssh-helper, we can now support remote session URIs qemu+ssh://host/session and this will only use virt-ssh-helper, with no fallback. This also lets the libvirtd process be auto-started, and connect directly to the modular daemons, avoiding use of virtproxyd back-compat tunnelling. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- docs/uri.html.in | 24 +++++++++- src/remote/remote_driver.c | 33 ++++++++++++- src/remote/remote_sockets.c | 8 ---- src/rpc/virnetclient.c | 96 +++++++++++++++++++++++++++++-------- src/rpc/virnetclient.h | 30 ++++++++++-- tests/virnetsockettest.c | 7 ++- 6 files changed, 162 insertions(+), 36 deletions(-) diff --git a/docs/uri.html.in b/docs/uri.html.in index 49f92773f8..27e36e099b 100644 --- a/docs/uri.html.in +++ b/docs/uri.html.in @@ -259,6 +259,24 @@ Note that parameter values must be <td colspan="2"/> <td> Example: <code>mode=direct</code> </td> </tr> + <tr> + <td> + <code>proxy</code> + </td> + <td>auto, netcat, native </td> + <td> + <dl> + <dt><code>auto</code></dt><dd>try native, fallback to netcat</dd> + <dt><code>netcat</code></dt><dd>only use netcat</dd> + <dt><code>native</code></dt><dd>only use native</dd> + </dl> + Can also be set in <code>libvirt.conf</code> as <code>remote_proxy</code> + </td> + </tr> + <tr> + <td colspan="2"/> + <td> Example: <code>proxy=native</code> </td> + </tr> <tr> <td> <code>command</code> @@ -296,8 +314,10 @@ Note that parameter values must be <td> ssh, libssh2, libssh </td> <td> The name of the netcat command on the remote machine. - The default is <code>nc</code>. For ssh transport, libvirt - constructs an ssh command which looks like: + The default is <code>nc</code>. This is not permitted + when using the <code>native</code> proxy mode. For ssh + transport, libvirt constructs an ssh command which looks + like: <pre><i>command</i> -p <i>port</i> [-l <i>username</i>] <i>hostname</i> <i>netcat</i> -U <i>socket</i> </pre> diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index d56f4b7260..88eb52ec4b 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -761,12 +761,14 @@ doRemoteOpen(virConnectPtr conn, g_autofree char *knownHosts = NULL; g_autofree char *mode_str = NULL; g_autofree char *daemon_name = NULL; + g_autofree char *proxy_str = NULL; bool sanity = true; bool verify = true; #ifndef WIN32 bool tty = true; #endif int mode; + int proxy; if (inside_daemon && !conn->uri->server) { mode = REMOTE_DRIVER_MODE_DIRECT; @@ -774,6 +776,14 @@ doRemoteOpen(virConnectPtr conn, mode = REMOTE_DRIVER_MODE_AUTO; } + /* Historically we didn't allow ssh tunnel with session mode, + * since we can't construct the accurate path remotely, + * so we can default to modern virt-ssh-helper */ + if (flags & VIR_DRV_OPEN_REMOTE_USER) + proxy = VIR_NET_CLIENT_PROXY_NATIVE; + else + proxy = VIR_NET_CLIENT_PROXY_AUTO; + /* We handle *ALL* URIs here. The caller has rejected any * URIs we don't care about */ @@ -813,6 +823,7 @@ doRemoteOpen(virConnectPtr conn, EXTRACT_URI_ARG_STR("known_hosts_verify", knownHostsVerify); EXTRACT_URI_ARG_STR("tls_priority", tls_priority); EXTRACT_URI_ARG_STR("mode", mode_str); + EXTRACT_URI_ARG_STR("proxy", proxy_str); EXTRACT_URI_ARG_BOOL("no_sanity", sanity); EXTRACT_URI_ARG_BOOL("no_verify", verify); #ifndef WIN32 @@ -865,6 +876,17 @@ doRemoteOpen(virConnectPtr conn, (mode = remoteDriverModeTypeFromString(mode_str)) < 0) goto failed; + if (conf && !proxy_str && + virConfGetValueString(conf, "remote_proxy", &proxy_str) < 0) + goto failed; + + if (proxy_str && + (proxy = virNetClientProxyTypeFromString(proxy_str)) < 0) { + virReportError(VIR_ERR_INVALID_ARG, + _("Unnkown proxy type '%s'"), proxy_str); + goto failed; + } + /* Sanity check that nothing requested !direct mode by mistake */ if (inside_daemon && !conn->uri->server && mode != REMOTE_DRIVER_MODE_DIRECT) { virReportError(VIR_ERR_INVALID_ARG, "%s", @@ -949,8 +971,11 @@ doRemoteOpen(virConnectPtr conn, knownHosts, knownHostsVerify, sshauth, + proxy, netcat, sockname, + name, + flags & VIR_DRV_OPEN_REMOTE_RO, auth, conn->uri); if (!priv->client) @@ -970,8 +995,11 @@ doRemoteOpen(virConnectPtr conn, knownHosts, knownHostsVerify, sshauth, + proxy, netcat, sockname, + name, + flags & VIR_DRV_OPEN_REMOTE_RO, auth, conn->uri); if (!priv->client) @@ -1011,8 +1039,11 @@ doRemoteOpen(virConnectPtr conn, !tty, !verify, keyfile, + proxy, netcat, - sockname))) + sockname, + name, + flags & VIR_DRV_OPEN_REMOTE_RO))) goto failed; priv->is_secure = 1; diff --git a/src/remote/remote_sockets.c b/src/remote/remote_sockets.c index 854775f401..7c69ed9e7f 100644 --- a/src/remote/remote_sockets.c +++ b/src/remote/remote_sockets.c @@ -108,14 +108,6 @@ remoteGetUNIXSocketHelper(remoteDriverTransport transport, g_autofree char *userdir = NULL; if (session) { - if (transport != REMOTE_DRIVER_TRANSPORT_UNIX) { - virReportError(VIR_ERR_OPERATION_UNSUPPORTED, - _("Connecting to session instance without " - "socket path is not supported by the %s " - "transport"), - remoteDriverTransportTypeToString(transport)); - return NULL; - } userdir = virGetUserRuntimeDirectory(); sockname = g_strdup_printf("%s/%s-sock", userdir, sock_prefix); diff --git a/src/rpc/virnetclient.c b/src/rpc/virnetclient.c index 72ece28f59..46a875a0cb 100644 --- a/src/rpc/virnetclient.c +++ b/src/rpc/virnetclient.c @@ -50,6 +50,10 @@ enum { VIR_NET_CLIENT_MODE_COMPLETE, }; +VIR_ENUM_IMPL(virNetClientProxy, + VIR_NET_CLIENT_PROXY_LAST, + "auto", "netcat", "native"); + struct _virNetClientCall { int mode; @@ -414,23 +418,64 @@ virNetClientDoubleEscapeShell(const char *str) } char * -virNetClientSSHHelperCommand(const char *netcatPath, - const char *socketPath) -{ - g_autofree char *netcatPathSafe = virNetClientDoubleEscapeShell(netcatPath); - - if (!netcatPath) - netcatPath = "nc"; +virNetClientSSHHelperCommand(virNetClientProxy proxy, + const char *netcatPath, + const char *socketPath, + const char *driverURI, + bool readonly) +{ + g_autofree char *netcatPathSafe = virNetClientDoubleEscapeShell(netcatPath ? netcatPath : "nc"); + g_autofree char *driverURISafe = virNetClientDoubleEscapeShell(driverURI); + g_autofree char *nccmd = NULL; + g_autofree char *helpercmd = NULL; + + /* If user gave a 'netcat' path in the URI, we must + * assume they want the legacy 'nc' based proxy, not + * our new virt-ssh-helper + */ + if (proxy == VIR_NET_CLIENT_PROXY_AUTO && + netcatPath != NULL) { + proxy = VIR_NET_CLIENT_PROXY_NETCAT; + } - return g_strdup_printf( - "sh -c " - "'if '%s' -q 2>&1 | grep \"requires an argument\" >/dev/null 2>&1; then " - "ARG=-q0;" + nccmd = g_strdup_printf( + "if '%s' -q 2>&1 | grep \"requires an argument\" >/dev/null 2>&1; then " + "ARG=-q0;" "else " - "ARG=;" + "ARG=;" "fi;" - "'%s' $ARG -U %s'", + "'%s' $ARG -U %s", netcatPathSafe, netcatPathSafe, socketPath); + + helpercmd = g_strdup_printf("virt-ssh-helper%s'%s'", + readonly ? " -r " : " ", + driverURISafe); + + switch (proxy) { + case VIR_NET_CLIENT_PROXY_AUTO: + return g_strdup_printf("sh -c 'which virt-nc 1>/dev/null 2>&1; " + "if test $? = 0; then " + " %s; " + "else" + " %s; " + "fi'", helpercmd, nccmd); + + case VIR_NET_CLIENT_PROXY_NETCAT: + return g_strdup_printf("sh -c '%s'", nccmd); + + case VIR_NET_CLIENT_PROXY_NATIVE: + if (netcatPath) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("netcat path not valid with native proxy mode")); + return NULL; + } + return g_strdup_printf("sh -c '%s'", helpercmd); + + case VIR_NET_CLIENT_PROXY_LAST: + default: + virReportEnumRangeError(virNetClientProxy, proxy); + return NULL; + } } @@ -445,15 +490,18 @@ virNetClientPtr virNetClientNewSSH(const char *nodename, bool noTTY, bool noVerify, const char *keyfile, + virNetClientProxy proxy, const char *netcatPath, - const char *socketPath) + const char *socketPath, + const char *driverURI, + bool readonly) { virNetSocketPtr sock; g_autofree char *command = NULL; - DEFAULT_VALUE(netcatPath, "nc"); - - command = virNetClientSSHHelperCommand(netcatPath, socketPath); + if (!(command = virNetClientSSHHelperCommand(proxy, netcatPath, socketPath, + driverURI, readonly))) + return NULL; if (virNetSocketNewConnectSSH(nodename, service, binary, username, noTTY, noVerify, keyfile, command, &sock) < 0) @@ -470,8 +518,11 @@ virNetClientPtr virNetClientNewLibSSH2(const char *host, const char *knownHostsPath, const char *knownHostsVerify, const char *authMethods, + virNetClientProxy proxy, const char *netcatPath, const char *socketPath, + const char *driverURI, + bool readonly, virConnectAuthPtr authPtr, virURIPtr uri) { @@ -510,7 +561,9 @@ virNetClientPtr virNetClientNewLibSSH2(const char *host, DEFAULT_VALUE(username, "root"); DEFAULT_VALUE(knownHostsVerify, "normal"); - command = virNetClientSSHHelperCommand(netcatPath, socketPath); + if (!(command = virNetClientSSHHelperCommand(proxy, netcatPath, socketPath, + driverURI, readonly))) + return NULL; if (virNetSocketNewConnectLibSSH2(host, port, family, @@ -530,8 +583,11 @@ virNetClientPtr virNetClientNewLibssh(const char *host, const char *knownHostsPath, const char *knownHostsVerify, const char *authMethods, + virNetClientProxy proxy, const char *netcatPath, const char *socketPath, + const char *driverURI, + bool readonly, virConnectAuthPtr authPtr, virURIPtr uri) { @@ -570,7 +626,9 @@ virNetClientPtr virNetClientNewLibssh(const char *host, DEFAULT_VALUE(username, "root"); DEFAULT_VALUE(knownHostsVerify, "normal"); - command = virNetClientSSHHelperCommand(netcatPath, socketPath); + if (!(command = virNetClientSSHHelperCommand(proxy, netcatPath, socketPath, + driverURI, readonly))) + return NULL; if (virNetSocketNewConnectLibssh(host, port, family, diff --git a/src/rpc/virnetclient.h b/src/rpc/virnetclient.h index 6fdc370083..4789316e32 100644 --- a/src/rpc/virnetclient.h +++ b/src/rpc/virnetclient.h @@ -30,9 +30,22 @@ #include "virobject.h" #include "viruri.h" +typedef enum { + VIR_NET_CLIENT_PROXY_AUTO, + VIR_NET_CLIENT_PROXY_NETCAT, + VIR_NET_CLIENT_PROXY_NATIVE, + + VIR_NET_CLIENT_PROXY_LAST, +} virNetClientProxy; + +VIR_ENUM_DECL(virNetClientProxy); + char * -virNetClientSSHHelperCommand(const char *netcatPath, - const char *socketPath); +virNetClientSSHHelperCommand(virNetClientProxy proxy, + const char *netcatPath, + const char *socketPath, + const char *driverURI, + bool readonly); virNetClientPtr virNetClientNewUNIX(const char *path, bool spawnDaemon, @@ -49,8 +62,11 @@ virNetClientPtr virNetClientNewSSH(const char *nodename, bool noTTY, bool noVerify, const char *keyfile, - const char *netcat, - const char *socketPath); + virNetClientProxy proxy, + const char *netcatPath, + const char *socketPath, + const char *driverURI, + bool readonly); virNetClientPtr virNetClientNewLibSSH2(const char *host, const char *port, @@ -60,8 +76,11 @@ virNetClientPtr virNetClientNewLibSSH2(const char *host, const char *knownHostsPath, const char *knownHostsVerify, const char *authMethods, + virNetClientProxy proxy, const char *netcatPath, const char *socketPath, + const char *driverURI, + bool readonly, virConnectAuthPtr authPtr, virURIPtr uri); @@ -73,8 +92,11 @@ virNetClientPtr virNetClientNewLibssh(const char *host, const char *knownHostsPath, const char *knownHostsVerify, const char *authMethods, + virNetClientProxy proxy, const char *netcatPath, const char *socketPath, + const char *driverURI, + bool readonly, virConnectAuthPtr authPtr, virURIPtr uri); diff --git a/tests/virnetsockettest.c b/tests/virnetsockettest.c index 31fe1f86f4..93835af62f 100644 --- a/tests/virnetsockettest.c +++ b/tests/virnetsockettest.c @@ -469,8 +469,11 @@ static int testSocketSSH(const void *opaque) virNetSocketPtr csock = NULL; /* Client socket */ int ret = -1; char buf[1024]; - g_autofree char *command = virNetClientSSHHelperCommand(data->netcat, - data->path); + g_autofree char *command = virNetClientSSHHelperCommand(VIR_NET_CLIENT_PROXY_AUTO, + data->netcat, + data->path, + "qemu:///session", + true); if (virNetSocketNewConnectSSH(data->nodename, data->service, -- 2.26.2
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/remote/remote_driver.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index 88eb52ec4b..cc1a10b775 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -873,8 +873,11 @@ doRemoteOpen(virConnectPtr conn, goto failed; if (mode_str && - (mode = remoteDriverModeTypeFromString(mode_str)) < 0) + (mode = remoteDriverModeTypeFromString(mode_str)) < 0) { + virReportError(VIR_ERR_INVALID_ARG, + _("Unknown remote mode '%s'"), mode_str); goto failed; + } if (conf && !proxy_str && virConfGetValueString(conf, "remote_proxy", &proxy_str) < 0) -- 2.26.2
Ping. On Fri, Aug 07, 2020 at 06:40:48PM +0100, Daniel P. Berrangé wrote:
We have long had a problem with use of netcat for ssh tunnelling because there's no guarantee the UNIX socket path the client builds will match the UNIX socket path the remote host uses. We don't even allow session mode SSH tunnelling for this reason. We also can't easily auto-spawn libvirtd in session mode.
With the introduction of modular daemons we also have potential for two completely different UNIX socket paths even for system mode, and the client can't know which to use.
The solution to all these problems is to introduce a custom netcat impl. Instead passing the UNIX socket path, we pass the libvirt driver URI. The custom netcat then decides which socket path to use based on the remote build host environment.
We still have to support netcat for interoperability with legacy libvirt versions, but we can default to the new virt-nc.
v4: Now with many fixed bugs to make it actually work v3: Now with more meson and less autotools !
Daniel P. Berrangé (11): rpc: merge logic for generating remote SSH shell script remote: push logic for default netcat binary into common helper remote: split off enums into separate source file remote: split out function for parsing URI scheme remote: parse the remote transport string earlier remote: split out function for constructing socket path remote: extract logic for determining daemon to connect to remote: introduce virt-ssh-helper binary rpc: switch order of args in virNetClientNewSSH rpc: use new virt-ssh-helper binary for remote tunnelling remote: fix error reporting for invalid daemon mode
build-aux/syntax-check.mk | 2 +- docs/uri.html.in | 24 +- libvirt.spec.in | 2 + po/POTFILES.in | 2 + src/libvirt_remote.syms | 1 + src/remote/meson.build | 18 ++ src/remote/remote_driver.c | 331 +++++-------------------- src/remote/remote_sockets.c | 277 +++++++++++++++++++++ src/remote/remote_sockets.h | 70 ++++++ src/remote/remote_ssh_helper.c | 425 +++++++++++++++++++++++++++++++++ src/rpc/virnetclient.c | 167 +++++++++---- src/rpc/virnetclient.h | 29 ++- src/rpc/virnetsocket.c | 37 +-- src/rpc/virnetsocket.h | 4 +- tests/virnetsockettest.c | 12 +- 15 files changed, 1030 insertions(+), 371 deletions(-) create mode 100644 src/remote/remote_sockets.c create mode 100644 src/remote/remote_sockets.h create mode 100644 src/remote/remote_ssh_helper.c
-- 2.26.2
Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
On 8/7/20 7:40 PM, Daniel P. Berrangé wrote:
We have long had a problem with use of netcat for ssh tunnelling because there's no guarantee the UNIX socket path the client builds will match the UNIX socket path the remote host uses. We don't even allow session mode SSH tunnelling for this reason. We also can't easily auto-spawn libvirtd in session mode.
With the introduction of modular daemons we also have potential for two completely different UNIX socket paths even for system mode, and the client can't know which to use.
The solution to all these problems is to introduce a custom netcat impl. Instead passing the UNIX socket path, we pass the libvirt driver URI. The custom netcat then decides which socket path to use based on the remote build host environment.
We still have to support netcat for interoperability with legacy libvirt versions, but we can default to the new virt-nc.
v4: Now with many fixed bugs to make it actually work v3: Now with more meson and less autotools !
Daniel P. Berrangé (11): rpc: merge logic for generating remote SSH shell script remote: push logic for default netcat binary into common helper remote: split off enums into separate source file remote: split out function for parsing URI scheme remote: parse the remote transport string earlier remote: split out function for constructing socket path remote: extract logic for determining daemon to connect to remote: introduce virt-ssh-helper binary rpc: switch order of args in virNetClientNewSSH rpc: use new virt-ssh-helper binary for remote tunnelling remote: fix error reporting for invalid daemon mode
build-aux/syntax-check.mk | 2 +- docs/uri.html.in | 24 +- libvirt.spec.in | 2 + po/POTFILES.in | 2 + src/libvirt_remote.syms | 1 + src/remote/meson.build | 18 ++ src/remote/remote_driver.c | 331 +++++-------------------- src/remote/remote_sockets.c | 277 +++++++++++++++++++++ src/remote/remote_sockets.h | 70 ++++++ src/remote/remote_ssh_helper.c | 425 +++++++++++++++++++++++++++++++++ src/rpc/virnetclient.c | 167 +++++++++---- src/rpc/virnetclient.h | 29 ++- src/rpc/virnetsocket.c | 37 +-- src/rpc/virnetsocket.h | 4 +- tests/virnetsockettest.c | 12 +- 15 files changed, 1030 insertions(+), 371 deletions(-) create mode 100644 src/remote/remote_sockets.c create mode 100644 src/remote/remote_sockets.h create mode 100644 src/remote/remote_ssh_helper.c
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Michal
On Fri, 2020-08-07 at 18:40 +0100, Daniel P. Berrangé wrote:
Daniel P. Berrangé (11): rpc: merge logic for generating remote SSH shell script remote: push logic for default netcat binary into common helper remote: split off enums into separate source file remote: split out function for parsing URI scheme remote: parse the remote transport string earlier remote: split out function for constructing socket path remote: extract logic for determining daemon to connect to remote: introduce virt-ssh-helper binary rpc: switch order of args in virNetClientNewSSH rpc: use new virt-ssh-helper binary for remote tunnelling remote: fix error reporting for invalid daemon mode
Can you please mention this in the release notes? It's quite an important change, although hopefully it will be completely transparent to users. -- Andrea Bolognani / Red Hat / Virtualization
participants (3)
-
Andrea Bolognani -
Daniel P. Berrangé -
Michal Prívozník