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tree-wide: port more code to use send_one_fd() and receive_one_fd()

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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.
This commit is contained in:
Lennart Poettering 2015-09-23 01:00:04 +02:00
parent 400f1a33cf
commit 3ee897d6c2
8 changed files with 47 additions and 136 deletions
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84
src/basic/util.c
View File

@ -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);
}

4
src/basic/util.h
View File

@ -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);

44
src/core/namespace.c
View File

@ -643,16 +643,7 @@ int setup_tmp_dirs(const char *id, char **tmp_dir, char **var_tmp_dir) {
int setup_netns(int netns_storage_socket[2]) {
_cleanup_close_ int netns = -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;
int r;
int r, q;
assert(netns_storage_socket);
assert(netns_storage_socket[0] >= 0);
@ -669,12 +660,8 @@ int setup_netns(int netns_storage_socket[2]) {
if (lockf(netns_storage_socket[0], F_LOCK, 0) < 0)
return -errno;
if (recvmsg(netns_storage_socket[0], &mh, MSG_DONTWAIT|MSG_CMSG_CLOEXEC) < 0) {
if (errno != EAGAIN) {
r = -errno;
goto fail;
}
netns = receive_one_fd(netns_storage_socket[0], MSG_DONTWAIT);
if (netns == -EAGAIN) {
/* Nothing stored yet, so let's create a new namespace */
if (unshare(CLONE_NEWNET) < 0) {
@ -691,15 +678,13 @@ int setup_netns(int netns_storage_socket[2]) {
}
r = 1;
} else if (netns < 0) {
r = netns;
goto fail;
} else {
/* Yay, found something, so let's join the namespace */
CMSG_FOREACH(cmsg, &mh)
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
assert(cmsg->cmsg_len == CMSG_LEN(sizeof(int)));
netns = *(int*) CMSG_DATA(cmsg);
}
if (setns(netns, CLONE_NEWNET) < 0) {
r = -errno;
goto fail;
@ -708,21 +693,14 @@ int setup_netns(int netns_storage_socket[2]) {
r = 0;
}
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), &netns, sizeof(int));
mh.msg_controllen = cmsg->cmsg_len;
if (sendmsg(netns_storage_socket[1], &mh, MSG_DONTWAIT|MSG_NOSIGNAL) < 0) {
r = -errno;
q = send_one_fd(netns_storage_socket[1], netns, MSG_DONTWAIT);
if (q < 0) {
r = q;
goto fail;
}
fail:
lockf(netns_storage_socket[0], F_ULOCK, 0);
return r;
}

8
src/import/importd.c
View File

@ -600,11 +600,11 @@ static int manager_on_notify(sd_event_source *s, int fd, uint32_t revents, void
cmsg_close_all(&msghdr);
CMSG_FOREACH(cmsg, &msghdr) {
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_CREDENTIALS && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
CMSG_FOREACH(cmsg, &msghdr)
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_CREDENTIALS &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
ucred = (struct ucred*) CMSG_DATA(cmsg);
}
if (msghdr.msg_flags & MSG_TRUNC) {
log_warning("Got overly long notification datagram, ignoring.");

26
src/journal/journal-send.c
View File

@ -212,11 +212,6 @@ _public_ int sd_journal_sendv(const struct iovec *iov, int n) {
.msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(sa.sun_path),
};
ssize_t k;
union {
struct cmsghdr cmsghdr;
uint8_t buf[CMSG_SPACE(sizeof(int))];
} control;
struct cmsghdr *cmsg;
bool have_syslog_identifier = false;
bool seal = true;
@ -335,26 +330,7 @@ _public_ int sd_journal_sendv(const struct iovec *iov, int n) {
return r;
}
mh.msg_iov = NULL;
mh.msg_iovlen = 0;
zero(control);
mh.msg_control = &control;
mh.msg_controllen = sizeof(control);
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), &buffer_fd, sizeof(int));
mh.msg_controllen = cmsg->cmsg_len;
k = sendmsg(fd, &mh, MSG_NOSIGNAL);
if (k < 0)
return -errno;
return 0;
return send_one_fd(fd, buffer_fd, 0);
}
static int fill_iovec_perror_and_send(const char *message, int skip, struct iovec iov[]) {

11
src/libsystemd/sd-bus/bus-container.c
View File

@ -217,15 +217,8 @@ int bus_container_connect_kernel(sd_bus *b) {
_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), &fd, sizeof(int));
mh.msg_controllen = cmsg->cmsg_len;
if (sendmsg(pair[1], &mh, MSG_NOSIGNAL) < 0)
r = send_one_fd(pair[1], fd, 0);
if (r < 0)
_exit(EXIT_FAILURE);
_exit(EXIT_SUCCESS);

4
src/nspawn/nspawn-expose-ports.c
View File

@ -194,7 +194,7 @@ int expose_port_send_rtnl(int send_fd) {
/* Store away the fd in the socket, so that it stays open as
* long as we run the child */
r = send_one_fd(send_fd, fd);
r = send_one_fd(send_fd, fd, 0);
if (r < 0)
return log_error_errno(r, "Failed to send netlink fd: %m");
@ -214,7 +214,7 @@ int expose_port_watch_rtnl(
assert(recv_fd >= 0);
assert(ret);
fd = receive_one_fd(recv_fd);
fd = receive_one_fd(recv_fd, 0);
if (fd < 0)
return log_error_errno(fd, "Failed to recv netlink fd: %m");

2
src/nspawn/nspawn.c
View File

@ -1291,7 +1291,7 @@ static int setup_kmsg(const char *dest, int kmsg_socket) {
/* Store away the fd in the socket, so that it stays open as
* long as we run the child */
r = send_one_fd(kmsg_socket, fd);
r = send_one_fd(kmsg_socket, fd, 0);
safe_close(fd);
if (r < 0)