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authorLennart Poettering <lennart@poettering.net>2015-09-23 01:00:04 +0200
committerLennart Poettering <lennart@poettering.net>2015-09-29 21:08:37 +0200
commit3ee897d6c2401effbc82f5eef35fce405781d6c8 (patch)
tree86d1d6e0c432a22aba4d51dee56015f8b85d8b9b /src/basic
parent400f1a33cf63ddaa41af5d5b0bcd5be73e0404a6 (diff)
tree-wide: port more code to use send_one_fd() and receive_one_fd()
Also, make it slightly more powerful, by accepting a flags argument, and make it safe for handling if more than one cmsg attribute happens to be attached.
Diffstat (limited to 'src/basic')
-rw-r--r--src/basic/util.c84
-rw-r--r--src/basic/util.h4
2 files changed, 26 insertions, 62 deletions
diff --git a/src/basic/util.c b/src/basic/util.c
index bc61ec0115..c788a1d58b 100644
--- a/src/basic/util.c
+++ b/src/basic/util.c
@@ -6201,15 +6201,6 @@ int ptsname_malloc(int fd, char **ret) {
int openpt_in_namespace(pid_t pid, int flags) {
_cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
_cleanup_close_pair_ int pair[2] = { -1, -1 };
- union {
- struct cmsghdr cmsghdr;
- uint8_t buf[CMSG_SPACE(sizeof(int))];
- } control = {};
- struct msghdr mh = {
- .msg_control = &control,
- .msg_controllen = sizeof(control),
- };
- struct cmsghdr *cmsg;
siginfo_t si;
pid_t child;
int r;
@@ -6243,15 +6234,7 @@ int openpt_in_namespace(pid_t pid, int flags) {
if (unlockpt(master) < 0)
_exit(EXIT_FAILURE);
- cmsg = CMSG_FIRSTHDR(&mh);
- cmsg->cmsg_level = SOL_SOCKET;
- cmsg->cmsg_type = SCM_RIGHTS;
- cmsg->cmsg_len = CMSG_LEN(sizeof(int));
- memcpy(CMSG_DATA(cmsg), &master, sizeof(int));
-
- mh.msg_controllen = cmsg->cmsg_len;
-
- if (sendmsg(pair[1], &mh, MSG_NOSIGNAL) < 0)
+ if (send_one_fd(pair[1], master, 0) < 0)
_exit(EXIT_FAILURE);
_exit(EXIT_SUCCESS);
@@ -6265,26 +6248,7 @@ int openpt_in_namespace(pid_t pid, int flags) {
if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
return -EIO;
- if (recvmsg(pair[0], &mh, MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) < 0)
- return -errno;
-
- CMSG_FOREACH(cmsg, &mh)
- if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
- int *fds;
- unsigned n_fds;
-
- fds = (int*) CMSG_DATA(cmsg);
- n_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
-
- if (n_fds != 1) {
- close_many(fds, n_fds);
- return -EIO;
- }
-
- return fds[0];
- }
-
- return -EIO;
+ return receive_one_fd(pair[0], 0);
}
ssize_t fgetxattrat_fake(int dirfd, const char *filename, const char *attribute, void *value, size_t size, int flags) {
@@ -6884,7 +6848,7 @@ int fgetxattr_malloc(int fd, const char *name, char **value) {
}
}
-int send_one_fd(int transport_fd, int fd) {
+int send_one_fd(int transport_fd, int fd, int flags) {
union {
struct cmsghdr cmsghdr;
uint8_t buf[CMSG_SPACE(sizeof(int))];
@@ -6894,7 +6858,6 @@ int send_one_fd(int transport_fd, int fd) {
.msg_controllen = sizeof(control),
};
struct cmsghdr *cmsg;
- ssize_t k;
assert(transport_fd >= 0);
assert(fd >= 0);
@@ -6906,14 +6869,13 @@ int send_one_fd(int transport_fd, int fd) {
memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
mh.msg_controllen = CMSG_SPACE(sizeof(int));
- k = sendmsg(transport_fd, &mh, MSG_NOSIGNAL);
- if (k < 0)
+ if (sendmsg(transport_fd, &mh, MSG_NOSIGNAL | flags) < 0)
return -errno;
return 0;
}
-int receive_one_fd(int transport_fd) {
+int receive_one_fd(int transport_fd, int flags) {
union {
struct cmsghdr cmsghdr;
uint8_t buf[CMSG_SPACE(sizeof(int))];
@@ -6922,33 +6884,35 @@ int receive_one_fd(int transport_fd) {
.msg_control = &control,
.msg_controllen = sizeof(control),
};
- struct cmsghdr *cmsg;
- ssize_t k;
+ struct cmsghdr *cmsg, *found = NULL;
assert(transport_fd >= 0);
/*
- * Receive a single FD via @transport_fd. We don't care for the
- * transport-type, but the caller must assure that no other CMSG types
- * than SCM_RIGHTS is enabled. We also retrieve a single FD at most, so
- * for packet-based transports, the caller must ensure to send only a
- * single FD per packet.
- * This is best used in combination with send_one_fd().
+ * Receive a single FD via @transport_fd. We don't care for
+ * the transport-type. We retrieve a single FD at most, so for
+ * packet-based transports, the caller must ensure to send
+ * only a single FD per packet. This is best used in
+ * combination with send_one_fd().
*/
- k = recvmsg(transport_fd, &mh, MSG_NOSIGNAL | MSG_CMSG_CLOEXEC);
- if (k < 0)
+ if (recvmsg(transport_fd, &mh, MSG_NOSIGNAL | MSG_CMSG_CLOEXEC | flags) < 0)
return -errno;
- cmsg = CMSG_FIRSTHDR(&mh);
- if (!cmsg || CMSG_NXTHDR(&mh, cmsg) ||
- cmsg->cmsg_level != SOL_SOCKET ||
- cmsg->cmsg_type != SCM_RIGHTS ||
- cmsg->cmsg_len != CMSG_LEN(sizeof(int)) ||
- *(const int *)CMSG_DATA(cmsg) < 0) {
+ CMSG_FOREACH(cmsg, &mh) {
+ if (cmsg->cmsg_level == SOL_SOCKET &&
+ cmsg->cmsg_type == SCM_RIGHTS &&
+ cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
+ assert(!found);
+ found = cmsg;
+ break;
+ }
+ }
+
+ if (!found) {
cmsg_close_all(&mh);
return -EIO;
}
- return *(const int *)CMSG_DATA(cmsg);
+ return *(int*) CMSG_DATA(found);
}
diff --git a/src/basic/util.h b/src/basic/util.h
index 56d9f037bf..e6417b4ccd 100644
--- a/src/basic/util.h
+++ b/src/basic/util.h
@@ -942,5 +942,5 @@ int reset_uid_gid(void);
int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink);
int fgetxattr_malloc(int fd, const char *name, char **value);
-int send_one_fd(int transport_fd, int fd);
-int receive_one_fd(int transport_fd);
+int send_one_fd(int transport_fd, int fd, int flags);
+int receive_one_fd(int transport_fd, int flags);