src/ipc.cc

   1 /*
   2  * DEBUG: section 54    Interprocess Communication
   3  * AUTHOR: Duane Wessels
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  */
  32
  33 #include "squid.h"
  34 #include "comm/Connection.h"
  35 #include "fd.h"
  36 #include "fde.h"
  37 #include "globals.h"
  38 #include "ip/Address.h"
  39 #include "SquidIpc.h"
  40 #include "tools.h"
  41 #include "rfc1738.h"
  42
  43 static const char *hello_string = "hi there\n";
  44 #define HELLO_BUF_SZ 32
  45 static char hello_buf[HELLO_BUF_SZ];
  46
  47 static int
  48 ipcCloseAllFD(int prfd, int pwfd, int crfd, int cwfd)
  49 {
  50     if (prfd >= 0)
  51         comm_close(prfd);
  52
  53     if (prfd != pwfd)
  54         if (pwfd >= 0)
  55             comm_close(pwfd);
  56
  57     if (crfd >= 0)
  58         comm_close(crfd);
  59
  60     if (crfd != cwfd)
  61         if (cwfd >= 0)
  62             comm_close(cwfd);
  63
  64     return -1;
  65 }
  66
  67 static void
  68 PutEnvironment()
  69 {
  70 #if HAVE_PUTENV
  71     char *env_str;
  72     int tmp_s;
  73     env_str = (char *)xcalloc((tmp_s = strlen(Debug::debugOptions) + 32), 1);
  74     snprintf(env_str, tmp_s, "SQUID_DEBUG=%s", Debug::debugOptions);
  75     putenv(env_str);
  76 #endif
  77 }
  78
  79 pid_t
  80 ipcCreate(int type, const char *prog, const char *const args[], const char *name, Ip::Address &local_addr, int *rfd, int *wfd, void **hIpc)
  81 {
  82     pid_t pid;
  83     Ip::Address ChS;
  84     Ip::Address PaS;
  85     struct addrinfo *AI = NULL;
  86     int crfd = -1;
  87     int prfd = -1;
  88     int cwfd = -1;
  89     int pwfd = -1;
  90     int fd;
  91     int t1, t2, t3;
  92     int x;
  93
  94 #if USE_POLL && _SQUID_OSF_
  95     assert(type != IPC_FIFO);
  96 #endif
  97
  98     if (rfd)
  99         *rfd = -1;
 100
 101     if (wfd)
 102         *wfd = -1;
 103
 104     if (hIpc)
 105         *hIpc = NULL;
 106
 107 // NP: no wrapping around d and c usage since we *want* code expansion
 108 #define IPC_CHECK_FAIL(f,d,c) \
 109     if ((f) < 0) { \
 110         debugs(54, DBG_CRITICAL, "ERROR: Failed to create helper " d " FD: " << c); \
 111         return ipcCloseAllFD(prfd, pwfd, crfd, cwfd); \
 112     } else void(0)
 113
 114     if (type == IPC_TCP_SOCKET) {
 115         crfd = cwfd = comm_open(SOCK_STREAM,
 116                                 0,
 117                                 local_addr,
 118                                 COMM_NOCLOEXEC,
 119                                 name);
 120         prfd = pwfd = comm_open(SOCK_STREAM,
 121                                 0,                      /* protocol */
 122                                 local_addr,
 123                                 0,                      /* blocking */
 124                                 name);
 125         IPC_CHECK_FAIL(crfd, "child read", "TCP " << local_addr);
 126         IPC_CHECK_FAIL(prfd, "parent read", "TCP " << local_addr);
 127     } else if (type == IPC_UDP_SOCKET) {
 128         crfd = cwfd = comm_open(SOCK_DGRAM,
 129                                 0,
 130                                 local_addr,
 131                                 COMM_NOCLOEXEC,
 132                                 name);
 133         prfd = pwfd = comm_open(SOCK_DGRAM,
 134                                 0,
 135                                 local_addr,
 136                                 0,
 137                                 name);
 138         IPC_CHECK_FAIL(crfd, "child read", "UDP" << local_addr);
 139         IPC_CHECK_FAIL(prfd, "parent read", "UDP" << local_addr);
 140     } else if (type == IPC_FIFO) {
 141         int p2c[2];
 142         int c2p[2];
 143
 144         if (pipe(p2c) < 0) {
 145             debugs(54, DBG_CRITICAL, "ipcCreate: pipe: " << xstrerror());
 146             return -1; // maybe ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
 147         }
 148         fd_open(prfd = p2c[0], FD_PIPE, "IPC FIFO Parent Read");
 149         fd_open(cwfd = p2c[1], FD_PIPE, "IPC FIFO Child Write");
 150
 151         if (pipe(c2p) < 0) {
 152             debugs(54, DBG_CRITICAL, "ipcCreate: pipe: " << xstrerror());
 153             return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
 154         }
 155         fd_open(crfd = c2p[0], FD_PIPE, "IPC FIFO Child Read");
 156         fd_open(pwfd = c2p[1], FD_PIPE, "IPC FIFO Parent Write");
 157
 158         IPC_CHECK_FAIL(crfd, "child read", "FIFO pipe");
 159         IPC_CHECK_FAIL(prfd, "parent read", "FIFO pipe");
 160
 161 #if HAVE_SOCKETPAIR && defined(AF_UNIX)
 162
 163     } else if (type == IPC_UNIX_STREAM) {
 164         int fds[2];
 165         int buflen = 32768;
 166
 167         if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) < 0) {
 168             debugs(54, DBG_CRITICAL, "ipcCreate: socketpair: " << xstrerror());
 169             return -1;
 170         }
 171
 172         setsockopt(fds[0], SOL_SOCKET, SO_SNDBUF, (void *) &buflen, sizeof(buflen));
 173         setsockopt(fds[0], SOL_SOCKET, SO_RCVBUF, (void *) &buflen, sizeof(buflen));
 174         setsockopt(fds[1], SOL_SOCKET, SO_SNDBUF, (void *) &buflen, sizeof(buflen));
 175         setsockopt(fds[1], SOL_SOCKET, SO_RCVBUF, (void *) &buflen, sizeof(buflen));
 176         fd_open(prfd = pwfd = fds[0], FD_PIPE, "IPC UNIX STREAM Parent");
 177         fd_open(crfd = cwfd = fds[1], FD_PIPE, "IPC UNIX STREAM Parent");
 178         IPC_CHECK_FAIL(crfd, "child read", "UDS socket");
 179         IPC_CHECK_FAIL(prfd, "parent read", "UDS socket");
 180
 181     } else if (type == IPC_UNIX_DGRAM) {
 182         int fds[2];
 183
 184         if (socketpair(AF_UNIX, SOCK_DGRAM, 0, fds) < 0) {
 185             debugs(54, DBG_CRITICAL, "ipcCreate: socketpair: " << xstrerror());
 186             return -1;
 187         }
 188
 189         fd_open(prfd = pwfd = fds[0], FD_PIPE, "IPC UNIX DGRAM Parent");
 190         fd_open(crfd = cwfd = fds[1], FD_PIPE, "IPC UNIX DGRAM Parent");
 191
 192         IPC_CHECK_FAIL(crfd, "child read", "UDS datagram");
 193         IPC_CHECK_FAIL(prfd, "parent read", "UDS datagram");
 194 #endif
 195
 196     } else {
 197         assert(IPC_NONE);
 198     }
 199
 200     debugs(54, 3, "ipcCreate: prfd FD " << prfd);
 201     debugs(54, 3, "ipcCreate: pwfd FD " << pwfd);
 202     debugs(54, 3, "ipcCreate: crfd FD " << crfd);
 203     debugs(54, 3, "ipcCreate: cwfd FD " << cwfd);
 204
 205     if (type == IPC_TCP_SOCKET || type == IPC_UDP_SOCKET) {
 206         PaS.InitAddrInfo(AI);
 207
 208         if (getsockname(pwfd, AI->ai_addr, &AI->ai_addrlen) < 0) {
 209             PaS.FreeAddrInfo(AI);
 210             debugs(54, DBG_CRITICAL, "ipcCreate: getsockname: " << xstrerror());
 211             return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
 212         }
 213
 214         PaS = *AI;
 215
 216         debugs(54, 3, "ipcCreate: FD " << pwfd << " sockaddr " << PaS);
 217
 218         PaS.FreeAddrInfo(AI);
 219
 220         ChS.InitAddrInfo(AI);
 221
 222         if (getsockname(crfd, AI->ai_addr, &AI->ai_addrlen) < 0) {
 223             ChS.FreeAddrInfo(AI);
 224             debugs(54, DBG_CRITICAL, "ipcCreate: getsockname: " << xstrerror());
 225             return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
 226         }
 227
 228         ChS = *AI;
 229
 230         ChS.FreeAddrInfo(AI);
 231
 232         debugs(54, 3, "ipcCreate: FD " << crfd << " sockaddr " << ChS );
 233
 234     }
 235
 236     if (type == IPC_TCP_SOCKET) {
 237         if (listen(crfd, 1) < 0) {
 238             debugs(54, DBG_IMPORTANT, "ipcCreate: listen FD " << crfd << ": " << xstrerror());
 239             return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
 240         }
 241
 242         debugs(54, 3, "ipcCreate: FD " << crfd << " listening...");
 243     }
 244
 245     /* flush or else we get dup data if unbuffered_logs is set */
 246     logsFlush();
 247
 248     if ((pid = fork()) < 0) {
 249         debugs(54, DBG_IMPORTANT, "ipcCreate: fork: " << xstrerror());
 250         return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
 251     }
 252
 253     if (pid > 0) {              /* parent */
 254         /* close shared socket with child */
 255         comm_close(crfd);
 256
 257         if (cwfd != crfd)
 258             comm_close(cwfd);
 259
 260         cwfd = crfd = -1;
 261
 262         if (type == IPC_TCP_SOCKET || type == IPC_UDP_SOCKET) {
 263             if (comm_connect_addr(pwfd, ChS) == COMM_ERROR)
 264                 return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
 265         }
 266
 267         memset(hello_buf, '\0', HELLO_BUF_SZ);
 268
 269         if (type == IPC_UDP_SOCKET)
 270             x = comm_udp_recv(prfd, hello_buf, HELLO_BUF_SZ - 1, 0);
 271         else
 272             x = read(prfd, hello_buf, HELLO_BUF_SZ - 1);
 273
 274         if (x < 0) {
 275             debugs(54, DBG_CRITICAL, "ipcCreate: PARENT: hello read test failed");
 276             debugs(54, DBG_CRITICAL, "--> read: " << xstrerror());
 277             return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
 278         } else if (strcmp(hello_buf, hello_string)) {
 279             debugs(54, DBG_CRITICAL, "ipcCreate: PARENT: hello read test failed");
 280             debugs(54, DBG_CRITICAL, "--> read returned " << x);
 281             debugs(54, DBG_CRITICAL, "--> got '" << rfc1738_escape(hello_buf) << "'");
 282             return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
 283         }
 284
 285         commUnsetFdTimeout(prfd);
 286         commSetNonBlocking(prfd);
 287         commSetNonBlocking(pwfd);
 288
 289         if (rfd)
 290             *rfd = prfd;
 291
 292         if (wfd)
 293             *wfd = pwfd;
 294
 295         fd_table[prfd].flags.ipc = 1;
 296
 297         fd_table[pwfd].flags.ipc = 1;
 298
 299         if (Config.sleep_after_fork) {
 300             /* XXX emulation of usleep() */
 301
 302             struct timeval sl;
 303             sl.tv_sec = Config.sleep_after_fork / 1000000;
 304             sl.tv_usec = Config.sleep_after_fork % 1000000;
 305             select(0, NULL, NULL, NULL, &sl);
 306         }
 307
 308         return pid;
 309     }
 310
 311     /* child */
 312     no_suid();                  /* give up extra priviliges */
 313
 314     /* close shared socket with parent */
 315     close(prfd);
 316
 317     if (pwfd != prfd)
 318         close(pwfd);
 319
 320     pwfd = prfd = -1;
 321
 322     if (type == IPC_TCP_SOCKET) {
 323         debugs(54, 3, "ipcCreate: calling accept on FD " << crfd);
 324
 325         if ((fd = accept(crfd, NULL, NULL)) < 0) {
 326             debugs(54, DBG_CRITICAL, "ipcCreate: FD " << crfd << " accept: " << xstrerror());
 327             _exit(1);
 328         }
 329
 330         debugs(54, 3, "ipcCreate: CHILD accepted new FD " << fd);
 331         close(crfd);
 332         cwfd = crfd = fd;
 333     } else if (type == IPC_UDP_SOCKET) {
 334         if (comm_connect_addr(crfd, PaS) == COMM_ERROR)
 335             return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
 336     }
 337
 338     if (type == IPC_UDP_SOCKET) {
 339         x = comm_udp_send(cwfd, hello_string, strlen(hello_string) + 1, 0);
 340
 341         if (x < 0) {
 342             debugs(54, DBG_CRITICAL, "sendto FD " << cwfd << ": " << xstrerror());
 343             debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: hello write test failed");
 344             _exit(1);
 345         }
 346     } else {
 347         if (write(cwfd, hello_string, strlen(hello_string) + 1) < 0) {
 348             debugs(54, DBG_CRITICAL, "write FD " << cwfd << ": " << xstrerror());
 349             debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: hello write test failed");
 350             _exit(1);
 351         }
 352     }
 353
 354     PutEnvironment();
 355     /*
 356      * This double-dup stuff avoids problems when one of
 357      *  crfd, cwfd, or debug_log are in the rage 0-2.
 358      */
 359
 360     do {
 361         /* First make sure 0-2 is occupied by something. Gets cleaned up later */
 362         x = dup(crfd);
 363         assert(x > -1);
 364     } while (x < 3 && x > -1);
 365
 366     close(x);
 367
 368     t1 = dup(crfd);
 369
 370     t2 = dup(cwfd);
 371
 372     t3 = dup(fileno(debug_log));
 373
 374     assert(t1 > 2 && t2 > 2 && t3 > 2);
 375
 376     close(crfd);
 377
 378     close(cwfd);
 379
 380     close(fileno(debug_log));
 381
 382     dup2(t1, 0);
 383
 384     dup2(t2, 1);
 385
 386     dup2(t3, 2);
 387
 388     close(t1);
 389
 390     close(t2);
 391
 392     close(t3);
 393
 394     /* Make sure all other filedescriptors are closed */
 395     for (x = 3; x < SQUID_MAXFD; ++x)
 396         close(x);
 397
 398 #if HAVE_SETSID
 399     if (opt_no_daemon)
 400         setsid();
 401 #endif
 402
 403     execvp(prog, (char *const *) args);
 404
 405     debug_log = fdopen(2, "a+");
 406
 407     debugs(54, DBG_CRITICAL, "ipcCreate: " << prog << ": " << xstrerror());
 408
 409     _exit(1);
 410
 411     return 0;
 412 }