diff options
| -rw-r--r-- | udevd.c | 30 | ||||
| -rw-r--r-- | udevsend.c | 37 |
2 files changed, 61 insertions, 6 deletions
@@ -222,6 +222,11 @@ static void handle_msg(int sock) { struct hotplug_msg *msg; int retval; + struct msghdr smsg; + struct cmsghdr *cmsg; + struct iovec iov; + struct ucred *cred; + char cred_msg[CMSG_SPACE(sizeof(struct ucred))]; msg = msg_create(); if (msg == NULL) { @@ -229,13 +234,30 @@ static void handle_msg(int sock) return; } - retval = recv(sock, msg, sizeof(struct hotplug_msg), 0); + iov.iov_base = msg; + iov.iov_len = sizeof(struct hotplug_msg); + + memset(&smsg, 0x00, sizeof(struct msghdr)); + smsg.msg_iov = &iov; + smsg.msg_iovlen = 1; + smsg.msg_control = cred_msg; + smsg.msg_controllen = sizeof(cred_msg); + + retval = recvmsg(sock, &smsg, 0); if (retval < 0) { if (errno != EINTR) dbg("unable to receive message"); return; } - + cmsg = CMSG_FIRSTHDR(&smsg); + cred = (struct ucred *) CMSG_DATA(cmsg); + + if (cred->uid != 0) { + dbg("sender uid=%i, message ignored", cred->uid); + free(msg); + return; + } + if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) { dbg("message magic '%s' doesn't match, ignore it", msg->magic); free(msg); @@ -289,6 +311,7 @@ int main(int argc, char *argv[]) struct sockaddr_un saddr; socklen_t addrlen; int retval; + const int on = 1; struct sigaction act; init_logging("udevd"); @@ -324,6 +347,9 @@ int main(int argc, char *argv[]) goto exit; } + /* enable receiving of the sender credentials */ + setsockopt(ssock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); + while (1) { handle_msg(ssock); diff --git a/udevsend.c b/udevsend.c index a24e7d75ed..b26c744422 100644 --- a/udevsend.c +++ b/udevsend.c @@ -119,7 +119,7 @@ static int start_daemon(void) int main(int argc, char* argv[]) { - struct hotplug_msg message; + struct hotplug_msg msg; char *action; char *devpath; char *subsystem; @@ -133,6 +133,13 @@ int main(int argc, char* argv[]) struct sockaddr_un saddr; socklen_t addrlen; int started_daemon = 0; + struct iovec iov; + struct msghdr smsg; + char cred_msg[CMSG_SPACE(sizeof(struct ucred))]; + struct cmsghdr *cmsg; + struct ucred *cred; + + #ifdef DEBUG init_logging("udevsend"); @@ -174,12 +181,34 @@ int main(int argc, char* argv[]) strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH); addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1; - size = build_hotplugmsg(&message, action, devpath, subsystem, seq); - + size = build_hotplugmsg(&msg, action, devpath, subsystem, seq); + + /* prepare message with credentials to authenticate ourself */ + iov.iov_base = &msg; + iov.iov_len = size; + + smsg.msg_name = &saddr; + smsg.msg_namelen = addrlen; + smsg.msg_iov = &iov; + smsg.msg_iovlen = 1; + smsg.msg_control = cred_msg; + smsg.msg_controllen = CMSG_LEN(sizeof(struct ucred));; + smsg.msg_flags = 0; + + cmsg = CMSG_FIRSTHDR(&smsg); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_CREDENTIALS; + cmsg->cmsg_len = sizeof(cred_msg); + cred = (struct ucred *) CMSG_DATA(cmsg); + cred->uid = getuid(); + cred->gid = getgid(); + cred->pid = getpid(); + cred->pid = getpid(); + /* If we can't send, try to start daemon and resend message */ loop = UDEVSEND_CONNECT_RETRY; while (loop--) { - retval = sendto(sock, &message, size, 0, (struct sockaddr *)&saddr, addrlen); + retval = sendmsg(sock, &smsg, 0); if (retval != -1) { retval = 0; goto close_and_exit; |