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 "config.h"
  20
  21 #include <signal.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <errno.h>
  25 #include <sys/stat.h>
  26 #include <sys/resource.h>
  27 #include <sys/socket.h>
  28 #include <netinet/in.h>
  29 #include <arpa/inet.h>
  30 #include <sys/types.h>
  31 #include <unistd.h>
  32 #include <pwd.h>
  33 #include <event.h>
  34 #include <limits.h>
  35
  36 #include "net.h"
  37 #include "util.h"
  38 #include "prot.h"
  39 #include "binlog.h"
  40
  41 static char *user = NULL;
  42 static int detach = 0;
  43 static int port = 11300;
  44 static struct in_addr host_addr;
  45
  46 static void
  47 nullfd(int fd, int flags)
  48 {
  49     int r;
  50
  51     close(fd);
  52     r = open("/dev/null", flags);
  53     if (r != fd) twarn("open(\"/dev/null\")"), exit(1);
  54 }
  55
  56 static void
  57 dfork()
  58 {
  59     pid_t p;
  60
  61     p = fork();
  62     if (p == -1) exit(1);
  63     if (p) exit(0);
  64 }
  65
  66 static void
  67 daemonize()
  68 {
  69     int r;
  70
  71     r = chdir("/");
  72     if (r) return twarn("chdir");
  73
  74     nullfd(0, O_RDONLY);
  75     nullfd(1, O_WRONLY);
  76     nullfd(2, O_WRONLY);
  77     umask(0);
  78     dfork();
  79     setsid();
  80     dfork();
  81 }
  82
  83 static void
  84 su(const char *user) {
  85     int r;
  86     struct passwd *pwent;
  87
  88     errno = 0;
  89     pwent = getpwnam(user);
  90     if (errno) twarn("getpwnam(\"%s\")", user), exit(32);
  91     if (!pwent) twarnx("getpwnam(\"%s\"): no such user", user), exit(33);
  92
  93     r = setgid(pwent->pw_gid);
  94     if (r == -1) twarn("setgid(%d \"%s\")", pwent->pw_gid, user), exit(34);
  95
  96     r = setuid(pwent->pw_uid);
  97     if (r == -1) twarn("setuid(%d \"%s\")", pwent->pw_uid, user), exit(34);
  98 }
  99
 100 void
 101 exit_cleanly(int sig)
 102 {
 103     binlog_shutdown();
 104     exit(0);
 105 }
 106
 107
 108 static void
 109 set_sig_handlers()
 110 {
 111     int r;
 112     struct sigaction sa;
 113
 114     sa.sa_handler = SIG_IGN;
 115     sa.sa_flags = 0;
 116     r = sigemptyset(&sa.sa_mask);
 117     if (r == -1) twarn("sigemptyset()"), exit(111);
 118
 119     r = sigaction(SIGPIPE, &sa, 0);
 120     if (r == -1) twarn("sigaction(SIGPIPE)"), exit(111);
 121
 122     sa.sa_handler = enter_drain_mode;
 123     r = sigaction(SIGUSR1, &sa, 0);
 124     if (r == -1) twarn("sigaction(SIGUSR1)"), exit(111);
 125
 126     sa.sa_handler = exit_cleanly;
 127     r = sigaction(SIGINT, &sa, 0);
 128     if (r == -1) twarn("sigaction(SIGINT)"), exit(111);
 129
 130     sa.sa_handler = exit_cleanly;
 131     r = sigaction(SIGTERM, &sa, 0);
 132     if (r == -1) twarn("sigaction(SIGTERM)"), exit(111);
 133 }
 134
 135 /* This is a workaround for a mystifying workaround in libevent's epoll
 136  * implementation. The epoll_init() function creates an epoll fd with space to
 137  * handle RLIMIT_NOFILE - 1 fds, accompanied by the following puzzling comment:
 138  * "Solaris is somewhat retarded - it's important to drop backwards
 139  * compatibility when making changes. So, don't dare to put rl.rlim_cur here."
 140  * This is presumably to work around a bug in Solaris, but it has the
 141  * unfortunate side-effect of causing epoll_ctl() (and, therefore, event_add())
 142  * to fail for a valid fd if we have hit the limit of open fds. That makes it
 143  * hard to provide reasonable behavior in that situation. So, let's reduce the
 144  * real value of RLIMIT_NOFILE by one, after epoll_init() has run. */
 145 static void
 146 nudge_fd_limit()
 147 {
 148     int r;
 149     struct rlimit rl;
 150
 151     r = getrlimit(RLIMIT_NOFILE, &rl);
 152     if (r != 0) twarn("getrlimit(RLIMIT_NOFILE)"), exit(2);
 153
 154     rl.rlim_cur--;
 155
 156     r = setrlimit(RLIMIT_NOFILE, &rl);
 157     if (r != 0) twarn("setrlimit(RLIMIT_NOFILE)"), exit(2);
 158 }
 159
 160 static void
 161 usage(char *msg, char *arg)
 162 {
 163     if (arg) warnx("%s: %s", msg, arg);
 164     fprintf(stderr, "Use: %s [OPTIONS]\n"
 165             "\n"
 166             "Options:\n"
 167             " -d       detach\n"
 168             " -b DIR   binlog directory\n"
 169             " -f MS    fsync at most once every MS milliseconds"
 170                        " (use -f 0 for \"always fsync\")\n"
 171             " -F       never fsync (default)\n"
 172             " -l ADDR  listen on address (default is 0.0.0.0)\n"
 173             " -p PORT  listen on port (default is 11300)\n"
 174             " -u USER  become user and group\n"
 175             " -z SIZE  set the maximum job size in bytes (default is %d)\n"
 176             " -s SIZE  set the size of each binlog file (default is %d)\n"
 177             " -v       show version information\n"
 178             " -h       show this help\n",
 179             progname, JOB_DATA_SIZE_LIMIT_DEFAULT, BINLOG_SIZE_LIMIT_DEFAULT);
 180     exit(arg ? 5 : 0);
 181 }
 182
 183 static size_t
 184 parse_size_t(char *str)
 185 {
 186     char r, x;
 187     size_t size;
 188
 189     r = sscanf(str, "%zu%c", &size, &x);
 190     if (1 != r) usage("invalid size", str);
 191     return size;
 192 }
 193
 194 static char *
 195 require_arg(char *opt, char *arg)
 196 {
 197     if (!arg) usage("option requires an argument", opt);
 198     return arg;
 199 }
 200
 201 static int
 202 parse_port(char *portstr)
 203 {
 204     int port;
 205     char *end;
 206
 207     errno = 0;
 208     port = strtol(portstr, &end, 10);
 209     if (end == portstr) usage("invalid port", portstr);
 210     if (end[0] != 0) usage("invalid port", portstr);
 211     if (errno) usage("invalid port", portstr);
 212
 213    return port;
 214 }
 215
 216 static struct in_addr
 217 parse_host(char *hoststr)
 218 {
 219     int r;
 220     struct in_addr addr;
 221
 222     r = inet_aton(hoststr, &addr);
 223     if (!r) usage("invalid address", hoststr);
 224
 225     return addr;
 226 }
 227
 228 static void
 229 opts(int argc, char **argv)
 230 {
 231     int i;
 232
 233     for (i = 1; i < argc; ++i) {
 234         if (argv[i][0] != '-') usage("unknown option", argv[i]);
 235         if (argv[i][1] == 0 || argv[i][2] != 0) usage("unknown option",argv[i]);
 236         switch (argv[i][1]) {
 237             case 'd':
 238                 detach = 1;
 239                 break;
 240             case 'p':
 241                 port = parse_port(require_arg("-p", argv[++i]));
 242                 break;
 243             case 'l':
 244                 host_addr = parse_host(require_arg("-l", argv[++i]));
 245                 break;
 246             case 'z':
 247                 job_data_size_limit = parse_size_t(require_arg("-z",
 248                                                                argv[++i]));
 249                 break;
 250             case 's':
 251                 binlog_size_limit = parse_size_t(require_arg("-s", argv[++i]));
 252                 break;
 253             case 'f':
 254                 fsync_throttle_ms = parse_size_t(require_arg("-f", argv[++i]));
 255                 enable_fsync = 1;
 256                 break;
 257             case 'F':
 258                 enable_fsync = 0;
 259                 break;
 260             case 'u':
 261                 user = require_arg("-u", argv[++i]);
 262                 break;
 263             case 'b':
 264                 binlog_dir = require_arg("-b", argv[++i]);
 265                 break;
 266             case 'h':
 267                 usage(NULL, NULL);
 268             case 'v':
 269                 printf("beanstalkd %s\n", VERSION);
 270                 exit(0);
 271             default:
 272                 usage("unknown option", argv[i]);
 273         }
 274     }
 275 }
 276
 277 int
 278 main(int argc, char **argv)
 279 {
 280     int r;
 281     struct event_base *ev_base;
 282     struct job binlog_jobs = {};
 283
 284     host_addr.s_addr = INADDR_ANY;
 285
 286     progname = argv[0];
 287     opts(argc, argv);
 288
 289     job_init();
 290     prot_init();
 291
 292     /* We want to make sure that only one beanstalkd tries to use the binlog
 293      * directory at a time. So acquire a lock now and never release it. */
 294     if (binlog_dir) {
 295         r = binlog_lock();
 296         if (!r) twarnx("failed to lock binlog dir %s", binlog_dir), exit(10);
 297     }
 298
 299     r = make_server_socket(host_addr, port);
 300     if (r == -1) twarnx("make_server_socket()"), exit(111);
 301
 302     if (user) su(user);
 303     ev_base = event_init();
 304     set_sig_handlers();
 305     nudge_fd_limit();
 306
 307     unbrake((evh) h_accept);
 308
 309     binlog_jobs.prev = binlog_jobs.next = &binlog_jobs;
 310     binlog_init(&binlog_jobs);
 311     prot_replay_binlog(&binlog_jobs);
 312
 313     if (detach) {
 314         daemonize();
 315         event_reinit(ev_base);
 316     }
 317
 318     event_dispatch();
 319     binlog_shutdown();
 320     twarnx("got here for some reason");
 321     return 0;
 322 }