X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevd.c;h=91189eb86153fc52046b104ff4d2523179fe2d1e;hp=9e0f71b58302ae7efa533f4c43ab2db4c3311a04;hb=82ca88904d1c9bf17f4434f54e12754c00eddcbd;hpb=1ceba9360b4de2f9ad3f20c23133bbfec027c036 diff --git a/udevd.c b/udevd.c index 9e0f71b58..91189eb86 100644 --- a/udevd.c +++ b/udevd.c @@ -33,20 +33,22 @@ #include #include #include -#include "klibc_fixups.h" #include #include #include "list.h" #include "udev.h" -#include "udev_lib.h" #include "udev_version.h" +#include "udev_utils.h" #include "udevd.h" #include "logging.h" +/* global variables*/ +static int udevsendsock; + static int pipefds[2]; static unsigned long long expected_seqnum = 0; -static volatile int children_waiting; +static volatile int sigchilds_waiting; static volatile int run_msg_q; static volatile int sig_flag; static int run_exec_q; @@ -58,11 +60,10 @@ static LIST_HEAD(running_list); static void exec_queue_manager(void); static void msg_queue_manager(void); static void user_sighandler(void); -static void reap_kids(void); +static void reap_sigchilds(void); char *udev_bin; #ifdef LOG -unsigned char logname[LOGNAME_SIZE]; void log_message (int level, const char *format, ...) { va_list args; @@ -87,16 +88,6 @@ static void msg_dump_queue(void) #endif } -static struct hotplug_msg *msg_create(void) -{ - struct hotplug_msg *new_msg; - - new_msg = malloc(sizeof(struct hotplug_msg)); - if (new_msg == NULL) - dbg("error malloc"); - return new_msg; -} - static void run_queue_delete(struct hotplug_msg *msg) { list_del(&msg->list); @@ -132,23 +123,16 @@ static void msg_queue_insert(struct hotplug_msg *msg) /* forks event and removes event from run queue when finished */ static void udev_run(struct hotplug_msg *msg) { + char *const argv[] = { "udev", msg->subsystem, NULL }; pid_t pid; - char action[ACTION_SIZE]; - char devpath[DEVPATH_SIZE]; - char seqnum[SEQNUM_SIZE]; - char *env[] = { action, devpath, seqnum, NULL }; - - snprintf(action, ACTION_SIZE-1, "ACTION=%s", msg->action); - action[ACTION_SIZE-1] = '\0'; - snprintf(devpath, DEVPATH_SIZE-1, "DEVPATH=%s", msg->devpath); - devpath[DEVPATH_SIZE-1] = '\0'; - sprintf(seqnum, "SEQNUM=%llu", msg->seqnum); pid = fork(); switch (pid) { case 0: /* child */ - execle(udev_bin, "udev", msg->subsystem, NULL, env); + close(udevsendsock); + logging_close(); + execve(udev_bin, argv, msg->envp); dbg("exec of child failed"); _exit(1); break; @@ -166,17 +150,40 @@ static void udev_run(struct hotplug_msg *msg) } } -/* returns already running task with devpath */ +/* returns still running task for the same event sequence */ static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg) { struct hotplug_msg *loop_msg; - list_for_each_entry(loop_msg, &running_list, list) - if (strncmp(loop_msg->devpath, msg->devpath, sizeof(loop_msg->devpath)) == 0) - return loop_msg; + int i; + + list_for_each_entry(loop_msg, &running_list, list) { + if (loop_msg->devpath == NULL || msg->devpath == NULL) + continue; + + /* is a parent or child device event still running */ + for (i = 0; i < DEVPATH_SIZE; i++) { + if (loop_msg->devpath[i] == '\0' || msg->devpath[i] == '\0') + return loop_msg; + + if (loop_msg->devpath[i] != msg->devpath[i]) + break; + } + + /* is the physical device event still running on an add sequence */ + if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0) + for (i = 0; i < DEVPATH_SIZE; i++) { + if (loop_msg->devpath[i] == '\0' || msg->physdevpath[i] == '\0') + return loop_msg; + + if (loop_msg->devpath[i] != msg->physdevpath[i]) + break; + } + } + return NULL; } -/* exec queue management routine executes the events and delays events for the same devpath */ +/* exec queue management routine executes the events and serializes events in the same sequence */ static void exec_queue_manager(void) { struct hotplug_msg *loop_msg; @@ -191,8 +198,8 @@ static void exec_queue_manager(void) udev_run(loop_msg); dbg("moved seq %llu to running list", loop_msg->seqnum); } else { - dbg("delay seq %llu, cause seq %llu already working on '%s'", - loop_msg->seqnum, msg->seqnum, msg->devpath); + dbg("delay seq %llu (%s), cause seq %llu (%s) is still running", + loop_msg->seqnum, loop_msg->devpath, msg->seqnum, msg->devpath); } } } @@ -246,24 +253,23 @@ recheck: } /* receive the msg, do some basic sanity checks, and queue it */ -static void handle_msg(int sock) +static void handle_udevsend_msg(int sock) { + static struct udevsend_msg usend_msg; struct hotplug_msg *msg; - int retval; + int bufpos; + int i; + ssize_t size; struct msghdr smsg; struct cmsghdr *cmsg; struct iovec iov; struct ucred *cred; char cred_msg[CMSG_SPACE(sizeof(struct ucred))]; + int envbuf_size; - msg = msg_create(); - if (msg == NULL) { - dbg("unable to store message"); - return; - } - - iov.iov_base = msg; - iov.iov_len = sizeof(struct hotplug_msg); + memset(&usend_msg, 0x00, sizeof(struct udevsend_msg)); + iov.iov_base = &usend_msg; + iov.iov_len = sizeof(struct udevsend_msg); memset(&smsg, 0x00, sizeof(struct msghdr)); smsg.msg_iov = &iov; @@ -271,8 +277,8 @@ static void handle_msg(int sock) smsg.msg_control = cred_msg; smsg.msg_controllen = sizeof(cred_msg); - retval = recvmsg(sock, &smsg, 0); - if (retval < 0) { + size = recvmsg(sock, &smsg, 0); + if (size < 0) { if (errno != EINTR) dbg("unable to receive message"); return; @@ -282,18 +288,55 @@ static void handle_msg(int sock) if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) { dbg("no sender credentials received, message ignored"); - goto skip; + goto exit; } if (cred->uid != 0) { dbg("sender uid=%i, message ignored", cred->uid); - goto skip; + goto exit; } - if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) { - dbg("message magic '%s' doesn't match, ignore it", msg->magic); - goto skip; + if (strncmp(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) { + dbg("message magic '%s' doesn't match, ignore it", usend_msg.magic); + goto exit; + } + + envbuf_size = size - offsetof(struct udevsend_msg, envbuf); + dbg("envbuf_size=%i", envbuf_size); + msg = malloc(sizeof(struct hotplug_msg) + envbuf_size); + memset(msg, 0x00, sizeof(struct hotplug_msg) + envbuf_size); + + /* copy environment buffer and reconstruct envp */ + memcpy(msg->envbuf, usend_msg.envbuf, envbuf_size); + bufpos = 0; + for (i = 0; (bufpos < envbuf_size) && (i < HOTPLUG_NUM_ENVP-2); i++) { + int keylen; + char *key; + + key = &msg->envbuf[bufpos]; + keylen = strlen(key); + msg->envp[i] = key; + bufpos += keylen + 1; + dbg("add '%s' to msg.envp[%i]", msg->envp[i], i); + + /* remember some keys for further processing */ + if (strncmp(key, "ACTION=", 7) == 0) + msg->action = &key[7]; + + if (strncmp(key, "DEVPATH=", 8) == 0) + msg->devpath = &key[8]; + + if (strncmp(key, "SUBSYSTEM=", 10) == 0) + msg->subsystem = &key[10]; + + if (strncmp(key, "SEQNUM=", 7) == 0) + msg->seqnum = strtoull(&key[7], NULL, 10); + + if (strncmp(key, "PHYSDEVPATH=", 12) == 0) + msg->physdevpath = &key[12]; } + msg->envp[i++] = "MANAGED_EVENT=1"; + msg->envp[i] = NULL; /* if no seqnum is given, we move straight to exec queue */ if (msg->seqnum == 0) { @@ -302,10 +345,8 @@ static void handle_msg(int sock) } else { msg_queue_insert(msg); } - return; -skip: - free(msg); +exit: return; } @@ -325,23 +366,18 @@ static void asmlinkage sig_handler(int signum) break; case SIGCHLD: /* set flag, then write to pipe if needed */ - children_waiting = 1; + sigchilds_waiting = 1; goto do_write; break; - default: - dbg("unhandled signal %d", signum); - return; } - + do_write: /* if pipe is empty, write to pipe to force select to return * immediately when it gets called */ if (!sig_flag) { rc = write(pipefds[1],&signum,sizeof(signum)); - if (rc < 0) - dbg("unable to write to pipe"); - else + if (rc >= 0) sig_flag = 1; } } @@ -366,9 +402,8 @@ static void udev_done(int pid) } } -static void reap_kids(void) +static void reap_sigchilds(void) { - /* reap all dead children */ while(1) { int pid = waitpid(-1, NULL, WNOHANG); if ((pid == -1) || (pid == 0)) @@ -378,13 +413,13 @@ static void reap_kids(void) } /* just read everything from the pipe and clear the flag, - * the useful flags were set in the signal handler + * the flags was set in the signal handler */ static void user_sighandler(void) { int sig; while(1) { - int rc = read(pipefds[0],&sig,sizeof(sig)); + int rc = read(pipefds[0], &sig, sizeof(sig)); if (rc < 0) break; @@ -392,14 +427,13 @@ static void user_sighandler(void) } } - -int main(int argc, char *argv[]) +int main(int argc, char *argv[], char *envp[]) { - int ssock, maxsockplus; + int maxsockplus; struct sockaddr_un saddr; socklen_t addrlen; int retval, fd; - const int on = 1; + const int feature_on = 1; struct sigaction act; fd_set readfds; @@ -408,55 +442,57 @@ int main(int argc, char *argv[]) if (getuid() != 0) { dbg("need to be root, exit"); - exit(1); + goto exit; } - /* make sure we are at top of dir */ + + /* make sure we don't lock any path */ chdir("/"); - umask( umask( 077 ) | 022 ); + umask(umask(077) | 022); + /* Set fds to dev/null */ fd = open( "/dev/null", O_RDWR ); if ( fd < 0 ) { dbg("error opening /dev/null %s", strerror(errno)); - exit(1); + goto exit; } dup2(fd, 0); dup2(fd, 1); dup2(fd, 2); if (fd > 2) close(fd); - /* Get new session id so stray signals don't come our way. */ + + /* become session leader */ setsid(); /* setup signal handler pipe */ retval = pipe(pipefds); if (retval < 0) { dbg("error getting pipes: %s", strerror(errno)); - exit(1); + goto exit; } retval = fcntl(pipefds[0], F_SETFL, O_NONBLOCK); if (retval < 0) { dbg("error fcntl on read pipe: %s", strerror(errno)); - exit(1); + goto exit; } retval = fcntl(pipefds[0], F_SETFD, FD_CLOEXEC); if (retval < 0) { dbg("error fcntl on read pipe: %s", strerror(errno)); - exit(1); + goto exit; } retval = fcntl(pipefds[1], F_SETFL, O_NONBLOCK); if (retval < 0) { dbg("error fcntl on write pipe: %s", strerror(errno)); - exit(1); + goto exit; } retval = fcntl(pipefds[1], F_SETFD, FD_CLOEXEC); if (retval < 0) { dbg("error fcntl on write pipe: %s", strerror(errno)); - exit(1); + goto exit; } - /* set signal handlers */ act.sa_handler = (void (*) (int))sig_handler; sigemptyset(&act.sa_mask); @@ -472,28 +508,22 @@ 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; - ssock = socket(AF_LOCAL, SOCK_DGRAM, 0); - if (ssock == -1) { + udevsendsock = socket(AF_LOCAL, SOCK_DGRAM, 0); + if (udevsendsock == -1) { dbg("error getting socket, exit"); - exit(1); + goto exit; } - set_cloexec_flag(ssock, 1); - /* the bind takes care of ensuring only one copy running */ - retval = bind(ssock, (struct sockaddr *) &saddr, addrlen); + retval = bind(udevsendsock, (struct sockaddr *) &saddr, addrlen); if (retval < 0) { dbg("bind failed, exit"); + close(udevsendsock); goto exit; } - retval = fcntl(ssock, F_SETFD, FD_CLOEXEC); - if (retval < 0) { - dbg("error fcntl on ssock: %s", strerror(errno)); - exit(1); - } /* enable receiving of the sender credentials */ - setsockopt(ssock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); + setsockopt(udevsendsock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on)); /* possible override of udev binary, used for testing */ udev_bin = getenv("UDEV_BIN"); @@ -503,9 +533,9 @@ int main(int argc, char *argv[]) udev_bin = UDEV_BIN; FD_ZERO(&readfds); - FD_SET(ssock, &readfds); + FD_SET(udevsendsock, &readfds); FD_SET(pipefds[0], &readfds); - maxsockplus = ssock+1; + maxsockplus = udevsendsock+1; while (1) { fd_set workreadfds = readfds; retval = select(maxsockplus, &workreadfds, NULL, NULL, NULL); @@ -516,15 +546,15 @@ int main(int argc, char *argv[]) continue; } - if (FD_ISSET(ssock, &workreadfds)) - handle_msg(ssock); + if (FD_ISSET(udevsendsock, &workreadfds)) + handle_udevsend_msg(udevsendsock); if (FD_ISSET(pipefds[0], &workreadfds)) user_sighandler(); - if (children_waiting) { - children_waiting = 0; - reap_kids(); + if (sigchilds_waiting) { + sigchilds_waiting = 0; + reap_sigchilds(); } if (run_msg_q) { @@ -533,22 +563,18 @@ int main(int argc, char *argv[]) } if (run_exec_q) { - /* this is tricky. exec_queue_manager() loops over exec_list, and - * calls running_with_devpath(), which loops over running_list. This gives - * O(N*M), which can get *nasty*. Clean up running_list before - * calling exec_queue_manager(). - */ - if (children_waiting) { - children_waiting = 0; - reap_kids(); + /* clean up running_list before calling exec_queue_manager() */ + if (sigchilds_waiting) { + sigchilds_waiting = 0; + reap_sigchilds(); } run_exec_q = 0; exec_queue_manager(); } } + exit: - close(ssock); logging_close(); - exit(1); + return 1; }