X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevd.c;h=c6642f4359b890d1cb63cdf75ddff4739df52fab;hp=f7901cb7529ca39a3873bf6bd561acd801040194;hb=8b72687876747186d5f1a5a45464bf64b1a166f5;hpb=896e5aa9aa6ea467a34b53d5053621b9cfc58548 diff --git a/udevd.c b/udevd.c index f7901cb75..c6642f435 100644 --- a/udevd.c +++ b/udevd.c @@ -28,31 +28,43 @@ #include #include #include -#include +#include #include #include #include -#include +#include +#include +#include #include "list.h" #include "udev.h" #include "udev_version.h" +#include "udev_utils.h" #include "udevd.h" #include "logging.h" -static int expected_seqnum = 0; -volatile static int children_waiting; -volatile static int msg_q_timeout; +/* global variables*/ +static int udevsendsock; -LIST_HEAD(msg_list); -LIST_HEAD(exec_list); -LIST_HEAD(running_list); +static int pipefds[2]; +static long startup_time; +static unsigned long long expected_seqnum = 0; +static volatile int sigchilds_waiting; +static volatile int run_msg_q; +static volatile int sig_flag; +static int run_exec_q; + +static LIST_HEAD(msg_list); +static LIST_HEAD(exec_list); +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_sigchilds(void); +char *udev_bin; #ifdef LOG -unsigned char logname[42]; void log_message (int level, const char *format, ...) { va_list args; @@ -63,54 +75,48 @@ void log_message (int level, const char *format, ...) } #endif +#define msg_dump(msg) \ + dbg("msg_dump: sequence %llu, '%s', '%s', '%s'", \ + msg->seqnum, msg->action, msg->devpath, msg->subsystem); + static void msg_dump_queue(void) { +#ifdef DEBUG struct hotplug_msg *msg; list_for_each_entry(msg, &msg_list, list) - dbg("sequence %d in queue", msg->seqnum); -} - -static void msg_dump(struct hotplug_msg *msg) -{ - dbg("sequence %d, '%s', '%s', '%s'", - msg->seqnum, msg->action, msg->devpath, msg->subsystem); -} - -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; + dbg("sequence %llu in queue", msg->seqnum); +#endif } static void run_queue_delete(struct hotplug_msg *msg) { list_del(&msg->list); free(msg); - exec_queue_manager(); } /* orders the message in the queue by sequence number */ static void msg_queue_insert(struct hotplug_msg *msg) { struct hotplug_msg *loop_msg; + struct sysinfo info; - /* sort message by sequence number into list*/ - list_for_each_entry(loop_msg, &msg_list, list) - if (loop_msg->seqnum > msg->seqnum) + /* sort message by sequence number into list. events + * will tend to come in order, so scan the list backwards + */ + list_for_each_entry_reverse(loop_msg, &msg_list, list) + if (loop_msg->seqnum < msg->seqnum) break; - list_add_tail(&msg->list, &loop_msg->list); - dbg("queued message seq %d", msg->seqnum); /* store timestamp of queuing */ - msg->queue_time = time(NULL); + sysinfo(&info); + msg->queue_time = info.uptime; + + list_add(&msg->list, &loop_msg->list); + dbg("queued message seq %llu", msg->seqnum); /* run msg queue manager */ - msg_queue_manager(); + run_msg_q = 1; return ; } @@ -118,45 +124,68 @@ 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[32]; - char devpath[256]; - char *env[] = { action, devpath, NULL }; - - snprintf(action, sizeof(action), "ACTION=%s", msg->action); - snprintf(devpath, sizeof(devpath), "DEVPATH=%s", msg->devpath); 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); + _exit(1); break; case -1: dbg("fork of child failed"); run_queue_delete(msg); + /* note: we never managed to run, so we had no impact on + * running_with_devpath(), so don't bother setting run_exec_q + */ break; default: /* get SIGCHLD in main loop */ - dbg("==> exec seq %d [%d] working at '%s'", msg->seqnum, pid, msg->devpath); + dbg("==> exec seq %llu [%d] working at '%s'", msg->seqnum, pid, msg->devpath); msg->pid = pid; } } -/* 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 */ -static void exec_queue_manager() +/* 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; struct hotplug_msg *tmp_msg; @@ -168,10 +197,10 @@ static void exec_queue_manager() /* move event to run list */ list_move_tail(&loop_msg->list, &running_list); udev_run(loop_msg); - dbg("moved seq %d to running list", loop_msg->seqnum); + dbg("moved seq %llu to running list", loop_msg->seqnum); } else { - dbg("delay seq %d, cause seq %d 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); } } } @@ -179,20 +208,23 @@ static void exec_queue_manager() static void msg_move_exec(struct hotplug_msg *msg) { list_move_tail(&msg->list, &exec_list); - exec_queue_manager(); + run_exec_q = 1; expected_seqnum = msg->seqnum+1; - dbg("moved seq %d to exec, next expected is %d", + dbg("moved seq %llu to exec, next expected is %llu", msg->seqnum, expected_seqnum); } /* msg queue management routine handles the timeouts and dispatches the events */ -static void msg_queue_manager() +static void msg_queue_manager(void) { struct hotplug_msg *loop_msg; struct hotplug_msg *tmp_msg; - time_t msg_age = 0; + struct sysinfo info; + long msg_age = 0; + static int timeout = EVENT_INIT_TIMEOUT_SEC; + static int init = 1; - dbg("msg queue manager, next expected is %d", expected_seqnum); + dbg("msg queue manager, next expected is %llu", expected_seqnum); recheck: list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) { /* move event with expected sequence to the exec list */ @@ -201,9 +233,18 @@ recheck: continue; } + /* see if we are in the initialization phase and wait for the very first events */ + if (init && (info.uptime - startup_time >= INIT_TIME_SEC)) { + init = 0; + timeout = EVENT_TIMEOUT_SEC; + dbg("initialization phase passed, set timeout to %i seconds", EVENT_TIMEOUT_SEC); + } + /* move event with expired timeout to the exec list */ - msg_age = time(NULL) - loop_msg->queue_time; - if (msg_age > EVENT_TIMEOUT_SEC-1) { + sysinfo(&info); + msg_age = info.uptime - loop_msg->queue_time; + dbg("seq %llu is %li seconds old", loop_msg->seqnum, msg_age); + if (msg_age >= timeout) { msg_move_exec(loop_msg); goto recheck; } else { @@ -213,34 +254,32 @@ recheck: msg_dump_queue(); + /* set timeout for remaining queued events */ if (list_empty(&msg_list) == 0) { - /* set timeout for remaining queued events */ - struct itimerval itv = {{0, 0}, {EVENT_TIMEOUT_SEC - msg_age, 0}}; - dbg("next event expires in %li seconds", - EVENT_TIMEOUT_SEC - msg_age); - setitimer(ITIMER_REAL, &itv, 0); + struct itimerval itv = {{0, 0}, {timeout - msg_age, 0}}; + dbg("next event expires in %li seconds", timeout - msg_age); + setitimer(ITIMER_REAL, &itv, NULL); } } /* 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; @@ -248,8 +287,8 @@ 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; @@ -259,48 +298,97 @@ 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(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) { + dbg("message magic '%s' doesn't match, ignore it", usend_msg.magic); + 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; + 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++] = "UDEVD_EVENT=1"; + msg->envp[i] = NULL; /* if no seqnum is given, we move straight to exec queue */ - if (msg->seqnum == -1) { + if (msg->seqnum == 0) { list_add(&msg->list, &exec_list); - exec_queue_manager(); + run_exec_q = 1; } else { msg_queue_insert(msg); } - return; -skip: - free(msg); +exit: return; } -static void sig_handler(int signum) +static void asmlinkage sig_handler(int signum) { + int rc; + switch (signum) { case SIGINT: case SIGTERM: exit(20 + signum); break; case SIGALRM: - msg_q_timeout = 1; + /* set flag, then write to pipe if needed */ + run_msg_q = 1; + goto do_write; break; case SIGCHLD: - children_waiting = 1; + /* set flag, then write to pipe if needed */ + sigchilds_waiting = 1; + goto do_write; break; - default: - dbg("unhandled signal"); + } + +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) + sig_flag = 1; } } @@ -311,39 +399,117 @@ static void udev_done(int pid) list_for_each_entry(msg, &running_list, list) { if (msg->pid == pid) { - dbg("<== exec seq %d came back", msg->seqnum); + dbg("<== exec seq %llu came back", msg->seqnum); run_queue_delete(msg); + + /* we want to run the exec queue manager since there may + * be events waiting with the devpath of the one that + * just finished + */ + run_exec_q = 1; return; } } } -int main(int argc, char *argv[]) +static void reap_sigchilds(void) { - int ssock; + while(1) { + int pid = waitpid(-1, NULL, WNOHANG); + if ((pid == -1) || (pid == 0)) + break; + udev_done(pid); + } +} + +/* just read everything from the pipe and clear the flag, + * 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)); + if (rc < 0) + break; + + sig_flag = 0; + } +} + +int main(int argc, char *argv[], char *envp[]) +{ + struct sysinfo info; + int maxsockplus; struct sockaddr_un saddr; socklen_t addrlen; - int retval; - const int on = 1; + int retval, fd; + const int feature_on = 1; struct sigaction act; + fd_set readfds; - init_logging("udevd"); + logging_init("udevd"); dbg("version %s", UDEV_VERSION); if (getuid() != 0) { dbg("need to be root, exit"); - exit(1); + goto exit; } - /* set signal handler */ - act.sa_handler = sig_handler; - sigemptyset (&act.sa_mask); + /* make sure we don't lock any path */ + chdir("/"); + 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)); + goto exit; + } + dup2(fd, 0); + dup2(fd, 1); + dup2(fd, 2); + if (fd > 2) + close(fd); + + /* become session leader */ + setsid(); + + /* setup signal handler pipe */ + retval = pipe(pipefds); + if (retval < 0) { + dbg("error getting pipes: %s", strerror(errno)); + goto exit; + } + + retval = fcntl(pipefds[0], F_SETFL, O_NONBLOCK); + if (retval < 0) { + dbg("error fcntl on read pipe: %s", strerror(errno)); + goto exit; + } + retval = fcntl(pipefds[0], F_SETFD, FD_CLOEXEC); + if (retval < 0) { + dbg("error fcntl on read pipe: %s", strerror(errno)); + goto exit; + } + + retval = fcntl(pipefds[1], F_SETFL, O_NONBLOCK); + if (retval < 0) { + dbg("error fcntl on write pipe: %s", strerror(errno)); + goto exit; + } + retval = fcntl(pipefds[1], F_SETFD, FD_CLOEXEC); + if (retval < 0) { + dbg("error fcntl on write pipe: %s", strerror(errno)); + goto exit; + } + + /* set signal handlers */ + act.sa_handler = (void (*) (int))sig_handler; + sigemptyset(&act.sa_mask); act.sa_flags = SA_RESTART; sigaction(SIGINT, &act, NULL); sigaction(SIGTERM, &act, NULL); - - /* we want these two to interrupt system calls */ - act.sa_flags = 0; sigaction(SIGALRM, &act, NULL); sigaction(SIGCHLD, &act, NULL); @@ -353,42 +519,77 @@ 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; } /* 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; } /* 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"); + if (udev_bin != NULL) + dbg("udev binary is set to '%s'", udev_bin); + else + udev_bin = UDEV_BIN; + + /* handle special startup timeout*/ + sysinfo(&info); + startup_time = info.uptime; + + FD_ZERO(&readfds); + FD_SET(udevsendsock, &readfds); + FD_SET(pipefds[0], &readfds); + maxsockplus = udevsendsock+1; while (1) { - handle_msg(ssock); + fd_set workreadfds = readfds; + retval = select(maxsockplus, &workreadfds, NULL, NULL, NULL); + + if (retval < 0) { + if (errno != EINTR) + dbg("error in select: %s", strerror(errno)); + continue; + } + + if (FD_ISSET(udevsendsock, &workreadfds)) + handle_udevsend_msg(udevsendsock); - while(msg_q_timeout) { - msg_q_timeout = 0; + if (FD_ISSET(pipefds[0], &workreadfds)) + user_sighandler(); + + if (sigchilds_waiting) { + sigchilds_waiting = 0; + reap_sigchilds(); + } + + if (run_msg_q) { + run_msg_q = 0; msg_queue_manager(); } - while(children_waiting) { - children_waiting = 0; - /* reap all dead children */ - while(1) { - int pid = waitpid(-1, 0, WNOHANG); - if ((pid == -1) || (pid == 0)) - break; - udev_done(pid); + if (run_exec_q) { + /* 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); - exit(1); + logging_close(); + return 1; }