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authorTom Gundersen <teg@jklm.no>2014-05-10 19:55:00 +0200
committerTom Gundersen <teg@jklm.no>2014-05-10 20:56:37 +0200
commit26349add97c8e9bfd26f2f16d61dd80a324f504e (patch)
tree673567fb1ae1adeae15813bd0b828c022175d2f2 /src/libsystemd/sd-rtnl
parent127dc4ea9487397b1ab70447e2f44d091e44ab5f (diff)
rtnl: message - verify that we read the pending message size from the kernel
Reuse the auth-checking for both the peek and the real read.
Diffstat (limited to 'src/libsystemd/sd-rtnl')
-rw-r--r--src/libsystemd/sd-rtnl/rtnl-message.c89
1 files changed, 50 insertions, 39 deletions
diff --git a/src/libsystemd/sd-rtnl/rtnl-message.c b/src/libsystemd/sd-rtnl/rtnl-message.c
index fb429864b9..9558e112af 100644
--- a/src/libsystemd/sd-rtnl/rtnl-message.c
+++ b/src/libsystemd/sd-rtnl/rtnl-message.c
@@ -1098,61 +1098,28 @@ int socket_write_message(sd_rtnl *nl, sd_rtnl_message *m) {
return k;
}
-/* On success, the number of bytes received is returned and *ret points to the received message
- * which has a valid header and the correct size.
- * If nothing useful was received 0 is returned.
- * On failure, a negative error code is returned.
- */
-int socket_read_message(sd_rtnl *rtnl) {
- _cleanup_rtnl_message_unref_ sd_rtnl_message *first = NULL;
+static int socket_recv_message(int fd, struct iovec *iov, bool peek) {
uint8_t cred_buffer[CMSG_SPACE(sizeof(struct ucred))];
- struct iovec iov = {};
struct msghdr msg = {
- .msg_iov = &iov,
+ .msg_iov = iov,
.msg_iovlen = 1,
.msg_control = cred_buffer,
.msg_controllen = sizeof(cred_buffer),
};
struct cmsghdr *cmsg;
- bool auth = false, multi_part = false, done = false;
- struct nlmsghdr *new_msg;
- size_t len;
+ bool auth = false;
int r;
- unsigned i = 0;
-
- assert(rtnl);
- assert(rtnl->rbuffer);
- assert(rtnl->rbuffer_allocated >= sizeof(struct nlmsghdr));
-
- /* read nothing, just get the pending message size */
- r = recvmsg(rtnl->fd, &msg, MSG_PEEK | MSG_TRUNC);
- if (r < 0)
- /* no data */
- return (errno == EAGAIN) ? 0 : -errno;
- else if (r == 0)
- /* connection was closed by the kernel */
- return -ECONNRESET;
- else
- len = (size_t)r;
-
- /* make room for the pending message */
- if (!greedy_realloc((void **)&rtnl->rbuffer,
- &rtnl->rbuffer_allocated,
- len, sizeof(uint8_t)))
- return -ENOMEM;
- iov.iov_base = rtnl->rbuffer;
- iov.iov_len = rtnl->rbuffer_allocated;
+ assert(fd >= 0);
+ assert(iov);
- r = recvmsg(rtnl->fd, &msg, MSG_TRUNC);
+ r = recvmsg(fd, &msg, MSG_TRUNC | (peek ? MSG_PEEK : 0));
if (r < 0)
/* no data */
return (errno == EAGAIN) ? 0 : -errno;
else if (r == 0)
/* connection was closed by the kernel */
return -ECONNRESET;
- else
- len = (size_t)r;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
@@ -1172,6 +1139,50 @@ int socket_read_message(sd_rtnl *rtnl) {
/* not from the kernel, ignore */
return 0;
+ return r;
+}
+
+/* On success, the number of bytes received is returned and *ret points to the received message
+ * which has a valid header and the correct size.
+ * If nothing useful was received 0 is returned.
+ * On failure, a negative error code is returned.
+ */
+int socket_read_message(sd_rtnl *rtnl) {
+ _cleanup_rtnl_message_unref_ sd_rtnl_message *first = NULL;
+ struct iovec iov = {};
+ bool multi_part = false, done = false;
+ struct nlmsghdr *new_msg;
+ size_t len;
+ int r;
+ unsigned i = 0;
+
+ assert(rtnl);
+ assert(rtnl->rbuffer);
+ assert(rtnl->rbuffer_allocated >= sizeof(struct nlmsghdr));
+
+ /* read nothing, just get the pending message size */
+ r = socket_recv_message(rtnl->fd, &iov, true);
+ if (r <= 0)
+ return r;
+ else
+ len = (size_t)r;
+
+ /* make room for the pending message */
+ if (!greedy_realloc((void **)&rtnl->rbuffer,
+ &rtnl->rbuffer_allocated,
+ len, sizeof(uint8_t)))
+ return -ENOMEM;
+
+ iov.iov_base = rtnl->rbuffer;
+ iov.iov_len = rtnl->rbuffer_allocated;
+
+ /* read the pending message */
+ r = socket_recv_message(rtnl->fd, &iov, false);
+ if (r <= 0)
+ return r;
+ else
+ len = (size_t)r;
+
if (len > rtnl->rbuffer_allocated)
/* message did not fit in read buffer */
return -EIO;