multipathd/uxlsnr.c

   1 /*
   2  * Original author : tridge@samba.org, January 2002
   3  *
   4  * Copyright (c) 2005 Christophe Varoqui
   5  * Copyright (c) 2005 Benjamin Marzinski, Redhat
   6  */
   7
   8 /*
   9  * A simple domain socket listener
  10  */
  11 #define _GNU_SOURCE
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <stdarg.h>
  16 #include <fcntl.h>
  17 #include <errno.h>
  18 #include <sys/ioctl.h>
  19 #include <sys/types.h>
  20 #include <sys/socket.h>
  21 #include <sys/un.h>
  22 #include <sys/poll.h>
  23 #include <sys/time.h>
  24 #include <signal.h>
  25 #include <checkers.h>
  26 #include <memory.h>
  27 #include <debug.h>
  28 #include <vector.h>
  29 #include <structs.h>
  30 #include <structs_vec.h>
  31 #include <uxsock.h>
  32 #include <defaults.h>
  33 #include <config.h>
  34
  35 #include "main.h"
  36 #include "cli.h"
  37 #include "uxlsnr.h"
  38
  39 struct timespec sleep_time = {5, 0};
  40
  41 struct client {
  42         int fd;
  43         struct client *next, *prev;
  44 };
  45
  46 static struct client *clients;
  47 static unsigned num_clients;
  48 struct pollfd *polls;
  49 volatile sig_atomic_t reconfig_sig = 0;
  50 volatile sig_atomic_t log_reset_sig = 0;
  51
  52 /*
  53  * handle a new client joining
  54  */
  55 static void new_client(int ux_sock)
  56 {
  57         struct client *c;
  58         struct sockaddr addr;
  59         socklen_t len = sizeof(addr);
  60         int fd;
  61
  62         fd = accept(ux_sock, &addr, &len);
  63
  64         if (fd == -1)
  65                 return;
  66
  67         /* put it in our linked list */
  68         c = (struct client *)MALLOC(sizeof(*c));
  69         memset(c, 0, sizeof(*c));
  70         c->fd = fd;
  71         c->next = clients;
  72         if (c->next) c->next->prev = c;
  73         clients = c;
  74         num_clients++;
  75 }
  76
  77 /*
  78  * kill off a dead client
  79  */
  80 static void dead_client(struct client *c)
  81 {
  82         close(c->fd);
  83         if (c->prev) c->prev->next = c->next;
  84         if (c->next) c->next->prev = c->prev;
  85         if (c == clients) clients = c->next;
  86         FREE(c);
  87         num_clients--;
  88 }
  89
  90 void free_polls (void)
  91 {
  92         if (polls)
  93                 FREE(polls);
  94 }
  95
  96 void check_timeout(struct timeval start_time, char *inbuf,
  97                    unsigned int timeout)
  98 {
  99         struct timeval diff_time, end_time;
 100
 101         if (start_time.tv_sec && gettimeofday(&end_time, NULL) == 0) {
 102                 timersub(&end_time, &start_time, &diff_time);
 103                 unsigned long msecs;
 104
 105                 msecs = diff_time.tv_sec * 1000 +
 106                         diff_time.tv_usec / 1000;
 107                 if (msecs > timeout)
 108                         condlog(2, "cli cmd '%s' timeout reached "
 109                                 "after %lu.%06lu secs", inbuf,
 110                                 diff_time.tv_sec, diff_time.tv_usec);
 111         }
 112 }
 113
 114 void uxsock_cleanup(void *arg)
 115 {
 116         cli_exit();
 117         free_polls();
 118 }
 119
 120 /*
 121  * entry point
 122  */
 123 void * uxsock_listen(int (*uxsock_trigger)(char *, char **, int *, void *),
 124                         void * trigger_data)
 125 {
 126         int ux_sock;
 127         size_t len;
 128         int rlen, timeout;
 129         char *inbuf;
 130         char *reply;
 131         sigset_t mask;
 132
 133         ux_sock = ux_socket_listen(DEFAULT_SOCKET);
 134
 135         if (ux_sock == -1) {
 136                 condlog(1, "could not create uxsock: %d", errno);
 137                 return NULL;
 138         }
 139
 140         if (!conf) {
 141                 condlog(1, "configuration changed");
 142                 return NULL;
 143         }
 144
 145         timeout = conf->uxsock_timeout;
 146
 147         pthread_cleanup_push(uxsock_cleanup, NULL);
 148
 149         polls = (struct pollfd *)MALLOC(0);
 150         pthread_sigmask(SIG_SETMASK, NULL, &mask);
 151         sigdelset(&mask, SIGHUP);
 152         sigdelset(&mask, SIGUSR1);
 153         while (1) {
 154                 struct client *c;
 155                 int i, poll_count;
 156
 157                 /*
 158                  * Store configuration timeout;
 159                  * configuration might change during
 160                  * the call to 'reconfigure'.
 161                  */
 162                 if (conf)
 163                         timeout = conf->uxsock_timeout;
 164
 165                 /* setup for a poll */
 166                 polls = REALLOC(polls, (1+num_clients) * sizeof(*polls));
 167                 polls[0].fd = ux_sock;
 168                 polls[0].events = POLLIN;
 169
 170                 /* setup the clients */
 171                 for (i=1, c = clients; c; i++, c = c->next) {
 172                         polls[i].fd = c->fd;
 173                         polls[i].events = POLLIN;
 174                 }
 175
 176                 /* most of our life is spent in this call */
 177                 poll_count = ppoll(polls, i, &sleep_time, &mask);
 178
 179                 if (poll_count == -1) {
 180                         if (errno == EINTR) {
 181                                 handle_signals();
 182                                 continue;
 183                         }
 184
 185                         /* something went badly wrong! */
 186                         condlog(0, "poll");
 187                         pthread_exit(NULL);
 188                 }
 189
 190                 if (poll_count == 0)
 191                         continue;
 192
 193                 /* see if a client wants to speak to us */
 194                 for (i=1, c = clients; c; i++) {
 195                         struct client *next = c->next;
 196
 197                         if (polls[i].revents & POLLIN) {
 198                                 struct timeval start_time;
 199
 200                                 if (gettimeofday(&start_time, NULL) != 0)
 201                                         start_time.tv_sec = 0;
 202
 203                                 if (recv_packet(c->fd, &inbuf, &len,
 204                                                 timeout) != 0) {
 205                                         dead_client(c);
 206                                 } else {
 207                                         inbuf[len - 1] = 0;
 208                                         condlog(4, "Got request [%s]", inbuf);
 209                                         uxsock_trigger(inbuf, &reply, &rlen,
 210                                                        trigger_data);
 211                                         if (reply) {
 212                                                 if (send_packet(c->fd, reply,
 213                                                                 rlen) != 0) {
 214                                                         dead_client(c);
 215                                                 }
 216                                                 condlog(4, "Reply [%d bytes]",
 217                                                         rlen);
 218                                                 FREE(reply);
 219                                                 reply = NULL;
 220                                         }
 221                                         check_timeout(start_time, inbuf,
 222                                                       timeout);
 223                                         FREE(inbuf);
 224                                 }
 225                         }
 226                         c = next;
 227                 }
 228
 229                 /* see if we got a new client */
 230                 if (polls[0].revents & POLLIN) {
 231                         new_client(ux_sock);
 232                 }
 233         }
 234
 235         pthread_cleanup_pop(1);
 236         close(ux_sock);
 237         return NULL;
 238 }