beanstalkd.c

   1 /* beanstalk - fast, general-purpose work queue */
   2
   3 /* Copyright (C) 2007 Keith Rarick and Philotic Inc.
   4
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <signal.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <errno.h>
  23 #include <sys/stat.h>
  24 #include <sys/resource.h>
  25 #include <sys/socket.h>
  26 #include <netinet/in.h>
  27 #include <arpa/inet.h>
  28 #include <sys/types.h>
  29 #include <unistd.h>
  30 #include <pwd.h>
  31 #include <event.h>
  32
  33 #include "net.h"
  34 #include "util.h"
  35 #include "prot.h"
  36 #include "config.h"
  37 #include "binlog.h"
  38
  39 static char *user = NULL;
  40 static int detach = 0;
  41 static int port = 11300;
  42 static struct in_addr host_addr;
  43
  44 static void
  45 nullfd(int fd, int flags)
  46 {
  47     int r;
  48
  49     close(fd);
  50     r = open("/dev/null", flags);
  51     if (r != fd) twarn("open(\"/dev/null\")"), exit(1);
  52 }
  53
  54 static void
  55 dfork()
  56 {
  57     pid_t p;
  58
  59     p = fork();
  60     if (p == -1) exit(1);
  61     if (p) exit(0);
  62 }
  63
  64 static void
  65 daemonize()
  66 {
  67     int r;
  68
  69     r = chdir("/");
  70     if (r) return twarn("chdir");
  71
  72     nullfd(0, O_RDONLY);
  73     nullfd(1, O_WRONLY);
  74     nullfd(2, O_WRONLY);
  75     umask(0);
  76     dfork();
  77     setsid();
  78     dfork();
  79 }
  80
  81 static void
  82 su(const char *user) {
  83     int r;
  84     struct passwd *pwent;
  85
  86     errno = 0;
  87     pwent = getpwnam(user);
  88     if (errno) twarn("getpwnam(\"%s\")", user), exit(32);
  89     if (!pwent) twarnx("getpwnam(\"%s\"): no such user", user), exit(33);
  90
  91     r = setgid(pwent->pw_gid);
  92     if (r == -1) twarn("setgid(%d \"%s\")", pwent->pw_gid, user), exit(34);
  93
  94     r = setuid(pwent->pw_uid);
  95     if (r == -1) twarn("setuid(%d \"%s\")", pwent->pw_uid, user), exit(34);
  96 }
  97
  98 void
  99 exit_cleanly(int sig)
 100 {
 101     binlog_shutdown();
 102     exit(0);
 103 }
 104
 105
 106 static void
 107 set_sig_handlers()
 108 {
 109     int r;
 110     struct sigaction sa;
 111
 112     sa.sa_handler = SIG_IGN;
 113     sa.sa_flags = 0;
 114     r = sigemptyset(&sa.sa_mask);
 115     if (r == -1) twarn("sigemptyset()"), exit(111);
 116
 117     r = sigaction(SIGPIPE, &sa, 0);
 118     if (r == -1) twarn("sigaction(SIGPIPE)"), exit(111);
 119
 120     sa.sa_handler = enter_drain_mode;
 121     r = sigaction(SIGUSR1, &sa, 0);
 122     if (r == -1) twarn("sigaction(SIGUSR1)"), exit(111);
 123
 124     sa.sa_handler = exit_cleanly;
 125     r = sigaction(SIGINT, &sa, 0);
 126     if (r == -1) twarn("sigaction(SIGINT)"), exit(111);
 127 }
 128
 129 /* This is a workaround for a mystifying workaround in libevent's epoll
 130  * implementation. The epoll_init() function creates an epoll fd with space to
 131  * handle RLIMIT_NOFILE - 1 fds, accompanied by the following puzzling comment:
 132  * "Solaris is somewhat retarded - it's important to drop backwards
 133  * compatibility when making changes. So, don't dare to put rl.rlim_cur here."
 134  * This is presumably to work around a bug in Solaris, but it has the
 135  * unfortunate side-effect of causing epoll_ctl() (and, therefore, event_add())
 136  * to fail for a valid fd if we have hit the limit of open fds. That makes it
 137  * hard to provide reasonable behavior in that situation. So, let's reduce the
 138  * real value of RLIMIT_NOFILE by one, after epoll_init() has run. */
 139 static void
 140 nudge_fd_limit()
 141 {
 142     int r;
 143     struct rlimit rl;
 144
 145     r = getrlimit(RLIMIT_NOFILE, &rl);
 146     if (r != 0) twarn("getrlimit(RLIMIT_NOFILE)"), exit(2);
 147
 148     rl.rlim_cur--;
 149
 150     r = setrlimit(RLIMIT_NOFILE, &rl);
 151     if (r != 0) twarn("setrlimit(RLIMIT_NOFILE)"), exit(2);
 152 }
 153
 154 static void
 155 usage(char *msg, char *arg)
 156 {
 157     if (arg) warnx("%s: %s", msg, arg);
 158     fprintf(stderr, "Use: %s [OPTIONS]\n"
 159             "\n"
 160             "Options:\n"
 161             " -d       detach\n"
 162             " -b DIR   binlog directory\n"
 163             " -l ADDR  listen on address (default is 0.0.0.0)\n"
 164             " -p PORT  listen on port (default is 11300)\n"
 165             " -u USER  become user and group\n"
 166             " -z SIZE  set the maximum job size in bytes (default is %d)\n"
 167             " -v       show version information\n"
 168             " -h       show this help\n",
 169             progname, JOB_DATA_SIZE_LIMIT_DEFAULT);
 170     exit(arg ? 5 : 0);
 171 }
 172
 173 static size_t
 174 parse_size_t(char *str)
 175 {
 176     char r, x;
 177     size_t size;
 178
 179     r = sscanf(str, "%zu%c", &size, &x);
 180     if (1 != r) usage("invalid size", str);
 181     return size;
 182 }
 183
 184 static char *
 185 require_arg(char *opt, char *arg)
 186 {
 187     if (!arg) usage("option requires an argument", opt);
 188     return arg;
 189 }
 190
 191 static int
 192 parse_port(char *portstr)
 193 {
 194     int port;
 195     char *end;
 196
 197     errno = 0;
 198     port = strtol(portstr, &end, 10);
 199     if (end == portstr) usage("invalid port", portstr);
 200     if (end[0] != 0) usage("invalid port", portstr);
 201     if (errno) usage("invalid port", portstr);
 202
 203    return port;
 204 }
 205
 206 static struct in_addr
 207 parse_host(char *hoststr)
 208 {
 209     int r;
 210     struct in_addr addr;
 211
 212     r = inet_aton(hoststr, &addr);
 213     if (!r) usage("invalid address", hoststr);
 214
 215     return addr;
 216 }
 217
 218 static void
 219 opts(int argc, char **argv)
 220 {
 221     int i;
 222
 223     for (i = 1; i < argc; ++i) {
 224         if (argv[i][0] != '-') usage("unknown option", argv[i]);
 225         if (argv[i][1] == 0 || argv[i][2] != 0) usage("unknown option",argv[i]);
 226         switch (argv[i][1]) {
 227             case 'd':
 228                 detach = 1;
 229                 break;
 230             case 'p':
 231                 port = parse_port(require_arg("-p", argv[++i]));
 232                 break;
 233             case 'l':
 234                 host_addr = parse_host(require_arg("-l", argv[++i]));
 235                 break;
 236             case 'z':
 237                 job_data_size_limit = parse_size_t(require_arg("-z",
 238                                                                argv[++i]));
 239                 break;
 240             case 'u':
 241                 user = require_arg("-u", argv[++i]);
 242                 break;
 243             case 'b':
 244                 binlog_dir = require_arg("-b", argv[++i]);
 245                 break;
 246             case 'h':
 247                 usage(NULL, NULL);
 248             case 'v':
 249                 printf("beanstalkd %s\n", VERSION);
 250                 exit(0);
 251             default:
 252                 usage("unknown option", argv[i]);
 253         }
 254     }
 255 }
 256
 257 int
 258 main(int argc, char **argv)
 259 {
 260     int r;
 261     struct event_base *ev_base;
 262     struct job binlog_jobs = {};
 263
 264     host_addr.s_addr = INADDR_ANY;
 265
 266     progname = argv[0];
 267     opts(argc, argv);
 268
 269     job_init();
 270     prot_init();
 271
 272     /* We want to make sure that only one beanstalkd tries to use the binlog
 273      * directory at a time. So acquire a lock now and never release it. */
 274     if (binlog_dir) {
 275         r = binlog_lock();
 276         if (!r) twarnx("failed to lock binlog dir %s", binlog_dir), exit(10);
 277     }
 278
 279     r = make_server_socket(host_addr, port);
 280     if (r == -1) twarnx("make_server_socket()"), exit(111);
 281
 282     if (user) su(user);
 283     ev_base = event_init();
 284     set_sig_handlers();
 285     nudge_fd_limit();
 286
 287     unbrake((evh) h_accept);
 288
 289     binlog_jobs.prev = binlog_jobs.next = &binlog_jobs;
 290     binlog_init(&binlog_jobs);
 291     prot_replay_binlog(&binlog_jobs);
 292
 293     if (detach) {
 294         daemonize();
 295         event_reinit(ev_base);
 296     }
 297
 298     event_dispatch();
 299     binlog_shutdown();
 300     twarnx("got here for some reason");
 301     return 0;
 302 }