[libvirt] [PATCH] build: use gnulib passfd for simpler SCM_RIGHTS code
* bootstrap.conf (gnulib_modules): Add passfd.
* src/util/util.c (virFileOpenAs): Simplify.
---
It's always nice to shove the maintenance burden onto gnulib.
bootstrap.conf | 1 +
src/util/util.c | 38 ++++++++------------------------------
2 files changed, 9 insertions(+), 30 deletions(-)
diff --git a/bootstrap.conf b/bootstrap.conf
index 293f86e..3b3a90f 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -52,6 +52,7 @@ mkstemps
mktempd
netdb
nonblocking
+passfd
perror
physmem
pipe-posix
diff --git a/src/util/util.c b/src/util/util.c
index d4d2610..de4e3b3 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -78,6 +78,7 @@
#include "files.h"
#include "command.h"
#include "nonblocking.h"
+#include "passfd.h"
#ifndef NSIG
# define NSIG 32
@@ -1480,11 +1481,6 @@ virFileOpenAs(const char *path, int openflags, mode_t mode,
int waitret, status, ret = 0;
int fd = -1;
int pair[2] = { -1, -1 };
- struct msghdr msg;
- struct cmsghdr *cmsg;
- char buf[CMSG_SPACE(sizeof(fd))];
- char dummy = 0;
- struct iovec iov;
int forkRet;
if ((!(flags & VIR_FILE_OPEN_AS_UID))
@@ -1506,18 +1502,6 @@ virFileOpenAs(const char *path, int openflags, mode_t mode,
return ret;
}
- memset(&msg, 0, sizeof(msg));
- iov.iov_base = &dummy;
- iov.iov_len = 1;
- msg.msg_iov = &iov;
- msg.msg_iovlen = 1;
- msg.msg_control = buf;
- msg.msg_controllen = sizeof(buf);
- cmsg = CMSG_FIRSTHDR(&msg);
- cmsg->cmsg_level = SOL_SOCKET;
- cmsg->cmsg_type = SCM_RIGHTS;
- cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
-
forkRet = virFork(&pid);
if (pid < 0) {
@@ -1529,26 +1513,20 @@ virFileOpenAs(const char *path, int openflags, mode_t mode,
VIR_FORCE_CLOSE(pair[1]);
do {
- ret = recvmsg(pair[0], &msg, 0);
+ ret = recvfd(pair[0], 0);
} while (ret < 0 && errno == EINTR);
- if (ret < 0) {
+ if (ret < 0 && errno != EACCES) {
ret = -errno;
VIR_FORCE_CLOSE(pair[0]);
while ((waitret = waitpid(pid, NULL, 0) == -1)
&& (errno == EINTR));
goto parenterror;
+ } else {
+ fd = ret;
}
VIR_FORCE_CLOSE(pair[0]);
- /* See if fd was transferred. */
- cmsg = CMSG_FIRSTHDR(&msg);
- if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(fd)) &&
- cmsg->cmsg_level == SOL_SOCKET &&
- cmsg->cmsg_type == SCM_RIGHTS) {
- memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
- }
-
/* wait for child to complete, and retrieve its exit code */
while ((waitret = waitpid(pid, &status, 0) == -1)
&& (errno == EINTR));
@@ -1557,12 +1535,14 @@ virFileOpenAs(const char *path, int openflags, mode_t mode,
virReportSystemError(errno,
_("failed to wait for child creating
'%s'"),
path);
+ VIR_FORCE_CLOSE(fd);
goto parenterror;
}
if (!WIFEXITED(status) || (ret = -WEXITSTATUS(status)) == -EACCES ||
fd == -1) {
/* fall back to the simpler method, which works better in
* some cases */
+ VIR_FORCE_CLOSE(fd);
return virFileOpenAsNoFork(path, openflags, mode, uid, gid, flags);
}
if (!ret)
@@ -1627,10 +1607,9 @@ parenterror:
path, mode);
goto childerror;
}
- memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd));
do {
- ret = sendmsg(pair[1], &msg, 0);
+ ret = sendfd(pair[1], fd);
} while (ret < 0 && errno == EINTR);
if (ret < 0) {
@@ -1638,7 +1617,6 @@ parenterror:
goto childerror;
}
- ret = 0;
childerror:
/* ret tracks -errno on failure, but exit value must be positive.
* If the child exits with EACCES, then the parent tries again. */
--
1.7.1