diff options
Diffstat (limited to 'udevd.c')
| -rw-r--r-- | udevd.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/udevd.c b/udevd.c new file mode 100644 index 0000000000..08dede36ee --- /dev/null +++ b/udevd.c @@ -0,0 +1,255 @@ +/* + * udevd.c + * + * Userspace devfs + * + * Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com> + * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> + * + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +#include <sys/types.h> +#include <sys/ipc.h> +#include <sys/msg.h> +#include <signal.h> +#include <unistd.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "udev.h" +#include "udevd.h" +#include "logging.h" + +#define BUFFER_SIZE 1024 +#define TIMEOUT_SECONDS 10 + +static void reset_timer(void); +static void reset_queue(void); + + +static int expect_seqnum = 0; +static int timeout_value = TIMEOUT_SECONDS; +static int timeout = 0; +static struct hotplug_msg *head = NULL; +static char exec_program[100]; + +static void sig_handler(int signum) +{ + dbg("caught signal %d", signum); + switch (signum) { + case SIGHUP: + dbg("reset requested, all waiting events killed"); + reset_timer(); + reset_queue(); + timeout = 0; + expect_seqnum = 0; + break; + + case SIGINT: + case SIGTERM: + case SIGKILL: + exit(20 + signum); + break; + + default: + dbg("unhandled signal"); + } +} + +static void sig_alarmhandler(int signum) +{ + dbg("caught signal %d", signum); + switch (signum) { + case SIGALRM: + timeout = 1; + dbg("event timeout reached"); + break; + + default: + dbg("unhandled signal"); + } +} + +static void dump_queue(void) +{ + struct hotplug_msg *p; + p = head; + + dbg("next expected sequence is %d", expect_seqnum); + while(p) { + dbg("sequence %d in queue", p->seqnum); + p=p->next; + } +} + +static void dump_msg(struct hotplug_msg *pmsg) +{ + dbg("sequence %d, '%s', '%s', '%s'", + pmsg->seqnum, pmsg->action, pmsg->devpath, pmsg->subsystem); +} + +static void dispatch_msg(struct hotplug_msg *pmsg) +{ + dump_msg(pmsg); + dbg("exec '%s'", exec_program); + setenv("ACTION", pmsg->action, 1); + setenv("DEVPATH", pmsg->devpath, 1); + execl(exec_program, pmsg->subsystem); +} + +static void reset_timer(void) +{ + alarm(0); +} + +static void set_timer(void) +{ + signal(SIGALRM, sig_alarmhandler); + alarm(timeout_value); +} + +static void reset_queue(void) +{ + struct hotplug_msg *p; + p = head; + + while(head) { + p = head; + head = head->next; + free(p); + } +} + +static void check_queue(void) +{ + struct hotplug_msg *p; + p = head; + + dump_queue(); + while(head && head->seqnum == expect_seqnum) { + dispatch_msg(head); + expect_seqnum++; + p = head; + head = head->next; + free(p); + } + if (head != NULL) + set_timer(); + else + reset_timer(); +} + +static void add_queue(struct hotplug_msg *pmsg) +{ + struct hotplug_msg *pnewmsg; + struct hotplug_msg *p; + struct hotplug_msg *p1; + + p = head; + p1 = NULL; + pnewmsg = malloc(sizeof(struct hotplug_msg)); + *pnewmsg = *pmsg; + pnewmsg->next = NULL; + while(p && pmsg->seqnum > p->seqnum) { + p1 = p; + p = p->next; + } + pnewmsg->next = p; + if (p1 == NULL) { + head = pnewmsg; + } else { + p1->next = pnewmsg; + } + dump_queue(); +} + +static int process_queue(void) +{ + int msgid; + key_t key; + struct hotplug_msg *pmsg; + char buf[BUFFER_SIZE]; + int ret; + + key = ftok(DEFAULT_EXEC_PROGRAM, IPC_KEY_ID); + pmsg = (struct hotplug_msg *) buf; + msgid = msgget(key, IPC_CREAT); + if (msgid == -1) { + dbg("open message queue error"); + goto exit; + } + while (1) { + ret = msgrcv(msgid, (struct msgbuf *) buf, BUFFER_SIZE-4, HOTPLUGMSGTYPE, 0); + if (ret != -1) { + dbg("current sequence %d, expected sequence %d", pmsg->seqnum, expect_seqnum); + + /* init expected sequence with value from first call */ + if (expect_seqnum == 0) { + expect_seqnum = pmsg->seqnum; + dbg("init next expected sequence number to %d", expect_seqnum); + } + + if (pmsg->seqnum > expect_seqnum) { + add_queue(pmsg); + set_timer(); + } else { + if (pmsg->seqnum == expect_seqnum) { + dispatch_msg(pmsg); + expect_seqnum++; + check_queue(); + } else { + dbg("timeout event for unexpected sequence number %d", pmsg->seqnum); + } + } + } else + if (errno == EINTR) { + if (head != NULL) { + /* timeout, skip all missing, proceed with next queued event */ + dbg("timeout reached, skip events %d - %d", expect_seqnum, head->seqnum-1); + expect_seqnum = head->seqnum; + } + check_queue(); + timeout = 0; + } else { + dbg("ipc message receive error '%s'", strerror(errno)); + } + } + return 0; +exit: + return -1; +} + +int main(int argc, char *argv[]) +{ + /* get program to exec on events */ + if (argc == 2) + strncpy(exec_program, argv[1], sizeof(exec_program)); + else + strcpy(exec_program, DEFAULT_EXEC_PROGRAM); + + /* set up signal handler */ + signal(SIGINT, sig_handler); + signal(SIGTERM, sig_handler); + signal(SIGKILL, sig_handler); + signal(SIGHUP, sig_handler); + + /* main loop */ + process_queue(); + return 0; +} |