[libvirt] [PATCH v2] qemu: unescape HMP commands before converting them to json

QMP commands don't need to be escaped since converting them to json also escapes special characters. When a QMP command fails, however, libvirt falls back to HMP commands. These fallback functions (qemuMonitorText*) do their own escaping, and pass the result directly to qemuMonitorHMPCommandWithFd. If the monitor is in json mode, these pre-escaped commands will be escaped again when converted to json, which can result in the wrong arguments being sent. For example, a filename test\file would be sent in json as test\\file. This prevented attaching an image file with a " or \ in its name in qemu 1.0.50, and also broke rbd attachment (which uses backslashes to escape some internal arguments.) Reported-by: Masuko Tomoya <tomoya.masuko(a)gmail.com&gt; Signed-off-by: Josh Durgin <josh.durgin(a)dreamhost.com&gt; --- Changes since v1: * fix leak of json_cmd * change comments to /* */ instead of // .gitignore | 1 + src/qemu/qemu_monitor.c | 67 ++++++++++++++++++++++++++-- src/qemu/qemu_monitor.h | 1 + tests/Makefile.am | 12 ++++- tests/qemumonitortest.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 188 insertions(+), 7 deletions(-) create mode 100644 tests/qemumonitortest.c diff --git a/.gitignore b/.gitignore index b7561dc..264a419 100644 --- a/.gitignore +++ b/.gitignore @@ -128,6 +128,7 @@ /tests/openvzutilstest /tests/qemuargv2xmltest /tests/qemuhelptest +/tests/qemumonitortest /tests/qemuxmlnstest /tests/qparamtest /tests/reconnect diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index 93f3505..1068280 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -153,6 +153,49 @@ char *qemuMonitorEscapeArg(const char *in) return out; } +char *qemuMonitorUnescapeArg(const char *in) +{ + int i, j; + char *out; + int len = strlen(in) + 1; + char next; + + if (VIR_ALLOC_N(out, len) < 0) + return NULL; + + for (i = j = 0; i < len; ++i) { + next = in[i]; + if (in[i] == '\\') { + if (len < i + 1) { + /* trailing backslash shouldn't be possible */ + VIR_FREE(out); + return NULL; + } + ++i; + switch(in[i]) { + case 'r': + next = '\r'; + break; + case 'n': + next = '\n'; + break; + case '"': + case '\\': + next = in[i]; + break; + default: + /* invalid input */ + VIR_FREE(out); + return NULL; + } + } + out[j++] = next; + } + out[j] = '\0'; + + return out; +} + #if DEBUG_RAW_IO # include <c-ctype.h> static char * qemuMonitorEscapeNonPrintable(const char *text) @@ -852,10 +895,26 @@ int qemuMonitorHMPCommandWithFd(qemuMonitorPtr mon, int scm_fd, char **reply) { - if (mon->json) - return qemuMonitorJSONHumanCommandWithFd(mon, cmd, scm_fd, reply); - else - return qemuMonitorTextCommandWithFd(mon, cmd, scm_fd, reply); + char *json_cmd = NULL; + int ret = -1; + + if (mon->json) { + /* hack to avoid complicating each call to text monitor functions */ + json_cmd = qemuMonitorUnescapeArg(cmd); + if (!json_cmd) { + VIR_DEBUG("Could not unescape command: %s", cmd); + qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Unable to unescape command")); + goto cleanup; + } + ret = qemuMonitorJSONHumanCommandWithFd(mon, json_cmd, scm_fd, reply); + } else { + ret = qemuMonitorTextCommandWithFd(mon, cmd, scm_fd, reply); + } + +cleanup: + VIR_FREE(json_cmd); + return ret; } /* Ensure proper locking around callbacks. */ diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index 7c6c52b..9768457 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -128,6 +128,7 @@ struct _qemuMonitorCallbacks { char *qemuMonitorEscapeArg(const char *in); +char *qemuMonitorUnescapeArg(const char *in); qemuMonitorPtr qemuMonitorOpen(virDomainObjPtr vm, virDomainChrSourceDefPtr config, diff --git a/tests/Makefile.am b/tests/Makefile.am index 9974c2f..3e505a5 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -72,6 +72,7 @@ EXTRA_DIST = \ nwfilterxml2xmlout \ oomtrace.pl \ qemuhelpdata \ + qemumonitortest \ qemuxml2argvdata \ qemuxml2xmloutdata \ qemuxmlnsdata \ @@ -110,7 +111,8 @@ check_PROGRAMS += xml2sexprtest sexpr2xmltest \ endif if WITH_QEMU check_PROGRAMS += qemuxml2argvtest qemuxml2xmltest qemuxmlnstest \ - qemuargv2xmltest qemuhelptest domainsnapshotxml2xmltest + qemuargv2xmltest qemuhelptest domainsnapshotxml2xmltest \ + qemumonitortest endif if WITH_OPENVZ @@ -237,7 +239,8 @@ endif if WITH_QEMU TESTS += qemuxml2argvtest qemuxml2xmltest qemuxmlnstest qemuargv2xmltest \ - qemuhelptest domainsnapshotxml2xmltest nwfilterxml2xmltest + qemuhelptest domainsnapshotxml2xmltest nwfilterxml2xmltest \ + qemumonitortest endif if WITH_OPENVZ @@ -365,6 +368,9 @@ qemuargv2xmltest_LDADD = $(qemu_LDADDS) $(LDADDS) qemuhelptest_SOURCES = qemuhelptest.c testutils.c testutils.h qemuhelptest_LDADD = $(qemu_LDADDS) $(LDADDS) +qemumonitortest_SOURCES = qemumonitortest.c testutils.c testutils.h +qemumonitortest_LDADD = $(qemu_LDADDS) $(LDADDS) + domainsnapshotxml2xmltest_SOURCES = \ domainsnapshotxml2xmltest.c testutilsqemu.c testutilsqemu.h \ testutils.c testutils.h @@ -372,7 +378,7 @@ domainsnapshotxml2xmltest_LDADD = $(qemu_LDADDS) $(LDADDS) else EXTRA_DIST += qemuxml2argvtest.c qemuxml2xmltest.c qemuargv2xmltest.c \ qemuxmlnstest.c qemuhelptest.c domainsnapshotxml2xmltest.c \ - testutilsqemu.c testutilsqemu.h + qemumonitortest.c testutilsqemu.c testutilsqemu.h endif if WITH_OPENVZ diff --git a/tests/qemumonitortest.c b/tests/qemumonitortest.c new file mode 100644 index 0000000..bf90502 --- /dev/null +++ b/tests/qemumonitortest.c @@ -0,0 +1,114 @@ +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#ifdef WITH_QEMU + +# include "internal.h" +# include "memory.h" +# include "testutils.h" +# include "util.h" +# include "qemu/qemu_monitor.h" + +struct testEscapeString +{ + const char* unescaped; + const char* escaped; +}; + +static struct testEscapeString escapeStrings[] = { + { "", "" }, + { " ", " " }, + { "\\", "\\\\" }, + { "\n", "\\n" }, + { "\r", "\\r" }, + { "\"", "\\\"" }, + { "\"\"\"\\\\\n\r\\\\\n\r\"\"\"", "\\\"\\\"\\\"\\\\\\\\\\n\\r\\\\\\\\\\n\\r\\\"\\\"\\\"" }, + { "drive_add dummy file=foo\\", "drive_add dummy file=foo\\\\" }, + { "block info", "block info" }, + { "set_password \":\\\"\"", "set_password \\\":\\\\\\\"\\\"" }, +}; + +static int testEscapeArg(const void *data ATTRIBUTE_UNUSED) +{ + int i; + char *escaped = NULL; + for (i = 0; i < ARRAY_CARDINALITY(escapeStrings); ++i) { + escaped = qemuMonitorEscapeArg(escapeStrings[i].unescaped); + if (!escaped) { + if (virTestGetDebug() > 0) { + fprintf(stderr, "\nUnescaped string [%s]\n", escapeStrings[i].unescaped); + fprintf(stderr, "Expect result [%s]\n", escapeStrings[i].escaped); + fprintf(stderr, "Actual result [%s]\n", escaped); + } + return -1; + } + if (STRNEQ(escapeStrings[i].escaped, escaped)) { + virtTestDifference(stderr, escapeStrings[i].escaped, escaped); + VIR_FREE(escaped); + return -1; + } + VIR_FREE(escaped); + } + + return 0; +} + +static int testUnescapeArg(const void *data ATTRIBUTE_UNUSED) +{ + int i; + char *unescaped = NULL; + for (i = 0; i < ARRAY_CARDINALITY(escapeStrings); ++i) { + unescaped = qemuMonitorUnescapeArg(escapeStrings[i].escaped); + if (!unescaped) { + if (virTestGetDebug() > 0) { + fprintf(stderr, "\nEscaped string [%s]\n", escapeStrings[i].escaped); + fprintf(stderr, "Expect result [%s]\n", escapeStrings[i].unescaped); + fprintf(stderr, "Actual result [%s]\n", unescaped); + } + return -1; + } + if (STRNEQ(escapeStrings[i].unescaped, unescaped)) { + virtTestDifference(stderr, escapeStrings[i].unescaped, unescaped); + VIR_FREE(unescaped); + return -1; + } + VIR_FREE(unescaped); + } + + return 0; +} + +static int +mymain(void) +{ + int result = 0; + +#define DO_TEST(_name) \ + do { \ + if (virtTestRun("qemu monitor "#_name, 1, test##_name, \ + NULL) < 0) { \ + result = -1; \ + } \ + } while (0) + + DO_TEST(EscapeArg); + DO_TEST(UnescapeArg); + + return result == 0 ? EXIT_SUCCESS : EXIT_FAILURE; +} + +VIRT_TEST_MAIN(mymain) + +#else +# include "testutils.h" + +int main(void) +{ + return EXIT_AM_SKIP; +} + +#endif /* WITH_QEMU */ -- 1.7.1