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sd-rtnl: use netlink header rather than ucred in socket_recv_message()

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Lets us simplify the function and drop SO_PASSCRED.

Thanks to Alexander Larsson and David Herrmann.
This commit is contained in:
Tom Gundersen
2015-06-11 16:14:59 +02:00
parent 4aa2764cad
commit 2ce8483538
2 changed files with 21 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/libsystemd/sd-rtnl/rtnl-message.c
+21 -27
View File
@@ -24,6 +24,7 @@
#include <unistd.h>
#include "util.h"
#include "socket-util.h"
#include "formats-util.h"
#include "refcnt.h"
#include "missing.h"
@@ -1415,17 +1416,18 @@ int socket_write_message(sd_rtnl *nl, sd_rtnl_message *m) {
}
static int socket_recv_message(int fd, struct iovec *iov, uint32_t *_group, bool peek) {
uint8_t cred_buffer[CMSG_SPACE(sizeof(struct ucred)) +
CMSG_SPACE(sizeof(struct nl_pktinfo))];
union sockaddr_union sender;
uint8_t cmsg_buffer[CMSG_SPACE(sizeof(struct nl_pktinfo))];
struct msghdr msg = {
.msg_iov = iov,
.msg_iovlen = 1,
.msg_control = cred_buffer,
.msg_controllen = sizeof(cred_buffer),
.msg_name = &sender,
.msg_namelen = sizeof(sender),
.msg_control = cmsg_buffer,
.msg_controllen = sizeof(cmsg_buffer),
};
struct cmsghdr *cmsg;
uint32_t group = 0;
bool auth = false;
int r;
assert(fd >= 0);
@@ -1442,29 +1444,10 @@ static int socket_recv_message(int fd, struct iovec *iov, uint32_t *_group, bool
return (errno == EAGAIN || errno == EINTR) ? 0 : -errno;
}
CMSG_FOREACH(cmsg, &msg) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_CREDENTIALS &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
struct ucred *ucred = (void *)CMSG_DATA(cmsg);
/* from the kernel */
if (ucred->pid == 0)
auth = true;
else
log_debug("rtnl: ignoring message from PID "PID_FMT, ucred->pid);
} else if (cmsg->cmsg_level == SOL_NETLINK &&
cmsg->cmsg_type == NETLINK_PKTINFO &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct nl_pktinfo))) {
struct nl_pktinfo *pktinfo = (void *)CMSG_DATA(cmsg);
/* multi-cast group */
group = pktinfo->group;
}
}
if (!auth) {
if (sender.nl.nl_pid != 0) {
/* not from the kernel, ignore */
log_debug("rtnl: ignoring message from portid %"PRIu32, sender.nl.nl_pid);
if (peek) {
/* drop the message */
r = recvmsg(fd, &msg, 0);
@@ -1475,6 +1458,17 @@ static int socket_recv_message(int fd, struct iovec *iov, uint32_t *_group, bool
return 0;
}
CMSG_FOREACH(cmsg, &msg) {
if (cmsg->cmsg_level == SOL_NETLINK &&
cmsg->cmsg_type == NETLINK_PKTINFO &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct nl_pktinfo))) {
struct nl_pktinfo *pktinfo = (void *)CMSG_DATA(cmsg);
/* multi-cast group */
group = pktinfo->group;
}
}
if (_group)
*_group = group;
src/libsystemd/sd-rtnl/sd-rtnl.c
-4
View File
@@ -136,10 +136,6 @@ static int rtnl_open_fd_ap(sd_rtnl **ret, int fd, unsigned n_groups, va_list ap)
if (r < 0)
return r;
r = setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
if (r < 0)
return -errno;
r = setsockopt(fd, SOL_NETLINK, NETLINK_PKTINFO, &one, sizeof(one));
if (r < 0)
return -errno;