X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevsend.c;h=5fe0f456a1d7e4dc65e8c3e2c989fc5aebaf93ed;hp=748c8f22173e8d17a621bc4aa605f158f43f5bc9;hb=915a12adc2ea28dc2391788c66b829caefefcfb4;hpb=90c210eb6bfc2ae294202fffb080315f3c47a57b diff --git a/udevsend.c b/udevsend.c index 748c8f221..5fe0f456a 100644 --- a/udevsend.c +++ b/udevsend.c @@ -23,130 +23,198 @@ */ #include -#include -#include +#include +#include +#include +#include #include #include #include +#include #include +#include +#include #include "udev.h" +#include "udev_version.h" #include "udevd.h" #include "logging.h" -static inline char *get_action(void) -{ - char *action; - - action = getenv("ACTION"); - return action; -} - -static inline char *get_devpath(void) -{ - char *devpath; - - devpath = getenv("DEVPATH"); - return devpath; -} +/* global variables */ +static int sock = -1; -static inline char *get_seqnum(void) +#ifdef LOG +void log_message (int level, const char *format, ...) { - char *seqnum; + va_list args; - seqnum = getenv("SEQNUM"); - return seqnum; + va_start(args, format); + vsyslog(level, format, args); + va_end(args); } +#endif -static int build_hotplugmsg(struct hotplug_msg **ppmsg, char *action, - char *devpath, char *subsystem, int seqnum) +static int start_daemon(void) { - struct hotplug_msg *pmsg; - - pmsg = malloc(sizeof(struct hotplug_msg)); - pmsg->mtype = HOTPLUGMSGTYPE; - pmsg->seqnum = seqnum; - strncpy(pmsg->action, action, 8); - strncpy(pmsg->devpath, devpath, 128); - strncpy(pmsg->subsystem, subsystem, 16); - *ppmsg = pmsg; - return sizeof(struct hotplug_msg); + pid_t pid; + pid_t child_pid; + char *const argv[] = { "udevd", NULL }; + char *const envp[] = { NULL }; + + pid = fork(); + switch (pid) { + case 0: + /* helper child */ + child_pid = fork(); + switch (child_pid) { + case 0: + /* daemon with empty environment */ + close(sock); + execve(UDEVD_BIN, argv, envp); + dbg("exec of daemon failed"); + _exit(1); + case -1: + dbg("fork of daemon failed"); + return -1; + default: + exit(0); + } + break; + case -1: + dbg("fork of helper failed"); + return -1; + default: + waitpid(pid, NULL, 0); + } + return 0; } -static void free_hotplugmsg(struct hotplug_msg *pmsg) +static void run_udev(const char *subsystem) { - free(pmsg); + char *const argv[] = { "udev", (char *)subsystem, NULL }; + pid_t pid; + + pid = fork(); + switch (pid) { + case 0: + /* child */ + execv(UDEV_BIN, argv); + dbg("exec of child failed"); + _exit(1); + break; + case -1: + dbg("fork of child failed"); + break; + default: + waitpid(pid, NULL, 0); + } } -int main(int argc, char* argv[]) +int main(int argc, char *argv[], char *envp[]) { - int msgid; - key_t key; - struct msqid_ds msg_queue; - struct msgbuf *pmsg; - char *action; - char *devpath; - char *subsystem; - char *seqnum; - int seq; - int retval = -EINVAL; - int size; - - subsystem = argv[1]; - if (subsystem == NULL) { - dbg("no subsystem"); - goto exit; + static struct udevsend_msg usend_msg; + int usend_msg_len; + int i; + int loop; + struct sockaddr_un saddr; + socklen_t addrlen; + int bufpos = 0; + int retval = 1; + int started_daemon = 0; + const char *subsystem = NULL; + + logging_init("udevsend"); + dbg("version %s", UDEV_VERSION); + + sock = socket(AF_LOCAL, SOCK_DGRAM, 0); + if (sock == -1) { + dbg("error getting socket"); + goto fallback; } - devpath = get_devpath(); - if (devpath == NULL) { - dbg("no devpath"); - goto exit; + memset(&saddr, 0x00, sizeof(struct sockaddr_un)); + saddr.sun_family = AF_LOCAL; + /* use abstract namespace for socket path */ + strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH); + addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1; + + memset(&usend_msg, 0x00, sizeof(struct udevsend_msg)); + strcpy(usend_msg.magic, UDEV_MAGIC); + + /* copy all keys to send buffer */ + for (i = 0; envp[i]; i++) { + const char *key; + int keylen; + + key = envp[i]; + keylen = strlen(key); + + /* prevent loops in the scripts we execute */ + if (strncmp(key, "UDEVD_EVENT=", 12) == 0) { + dbg("seems that the event source is not the kernel, just exit"); + goto exit; + } + + if (bufpos + keylen >= HOTPLUG_BUFFER_SIZE-1) { + dbg("environment buffer too small, probably not called by the kernel"); + continue; + } + + /* remember the SUBSYSTEM */ + if (strncmp(key, "SUBSYSTEM=", 10) == 0) + subsystem = &key[10]; + + dbg("add '%s' to env[%i] buffer", key, i); + strcpy(&usend_msg.envbuf[bufpos], key); + bufpos += keylen + 1; } - - action = get_action(); - if (action == NULL) { - dbg("no action"); - goto exit; + /* older kernels passed the SUBSYSTEM only as the first argument */ + if (!subsystem && argc == 2) { + bufpos += sprintf(&usend_msg.envbuf[bufpos], "SUBSYSTEM=%s", argv[1]) + 1; + dbg("add 'SUBSYSTEM=%s' to env[%i] buffer from argv", argv[1], i); } - seqnum = get_seqnum(); - if (seqnum == NULL) { - dbg("no seqnum"); - goto exit; - } - seq = atoi(seqnum); - - /* create ipc message queue or get id of our existing one */ - key = ftok(DEFAULT_EXEC_PROGRAM, IPC_KEY_ID); - size = build_hotplugmsg( (struct hotplug_msg**) &pmsg, action, devpath, subsystem, seq); - msgid = msgget(key, IPC_CREAT); - if (msgid == -1) { - dbg("error open ipc queue"); - goto exit; + usend_msg_len = offsetof(struct udevsend_msg, envbuf) + bufpos; + dbg("usend_msg_len=%i", usend_msg_len); + + /* If we can't send, try to start daemon and resend message */ + loop = SEND_WAIT_MAX_SECONDS * SEND_WAIT_LOOP_PER_SECOND; + while (--loop) { + retval = sendto(sock, &usend_msg, usend_msg_len, 0, (struct sockaddr *)&saddr, addrlen); + if (retval != -1) { + retval = 0; + goto exit; + } + + if (errno != ECONNREFUSED) { + dbg("error sending message (%s)", strerror(errno)); + goto fallback; + } + + if (!started_daemon) { + dbg("try to start udevd daemon"); + retval = start_daemon(); + if (retval) { + dbg("error starting daemon"); + goto fallback; + } + dbg("udevd daemon started"); + started_daemon = 1; + } else { + dbg("retry to connect %d", SEND_WAIT_MAX_SECONDS * SEND_WAIT_LOOP_PER_SECOND - loop); + usleep(1000 * 1000 / SEND_WAIT_LOOP_PER_SECOND); + } } - /* get state of ipc queue */ - retval = msgctl(msgid, IPC_STAT, &msg_queue); - if (retval == -1) { - dbg("error getting info on ipc queue"); - goto exit; - } - if (msg_queue.msg_qnum > 0) - dbg("%li messages already in the ipc queue", msg_queue.msg_qnum); - - /* send ipc message to the daemon */ - retval = msgsnd(msgid, pmsg, size, 0); - free_hotplugmsg( (struct hotplug_msg*) pmsg); - if (retval == -1) { - dbg("error sending ipc message"); - goto exit; - } - return 0; +fallback: + info("unable to connect to event daemon, try to call udev directly"); + run_udev(subsystem); exit: - if (retval > 0) - retval = 0; + if (sock != -1) + close(sock); + + logging_close(); return retval; }