/* * $Id: unlinkd.c,v 1.53 2006/09/08 19:41:24 serassio Exp $ * * DEBUG: section 2 Unlink Daemon * AUTHOR: Duane Wessels * * SQUID Web Proxy Cache http://www.squid-cache.org/ * ---------------------------------------------------------- * * Squid is the result of efforts by numerous individuals from * the Internet community; see the CONTRIBUTORS file for full * details. Many organizations have provided support for Squid's * development; see the SPONSORS file for full details. Squid is * Copyrighted (C) 2001 by the Regents of the University of * California; see the COPYRIGHT file for full details. Squid * incorporates software developed and/or copyrighted by other * sources; see the CREDITS file for full details. * * 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; either version 2 of the License, or * (at your option) any later version. * * 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., 59 Temple Place, Suite 330, Boston, MA 02111, USA. * */ #include "squid.h" #ifdef UNLINK_DAEMON /* This is the external unlinkd process */ #define UNLINK_BUF_LEN 1024 int main(int argc, char *argv[]) { char buf[UNLINK_BUF_LEN]; char *t; int x; setbuf(stdin, NULL); setbuf(stdout, NULL); close(2); open(_PATH_DEVNULL, O_RDWR); while (fgets(buf, UNLINK_BUF_LEN, stdin)) { if ((t = strchr(buf, '\n'))) *t = '\0'; #if USE_TRUNCATE x = truncate(buf, 0); #else x = unlink(buf); #endif if (x < 0) printf("ERR\n"); else printf("OK\n"); } exit(0); } #else /* UNLINK_DAEMON */ /* This code gets linked to Squid */ static int unlinkd_wfd = -1; static int unlinkd_rfd = -1; static void *hIpc; static pid_t pid; #define UNLINKD_QUEUE_LIMIT 20 void unlinkdUnlink(const char *path) { char buf[MAXPATHLEN]; int l; int x; static int queuelen = 0; if (unlinkd_wfd < 0) { debug_trap("unlinkdUnlink: unlinkd_wfd < 0"); safeunlink(path, 0); return; } /* * If the queue length is greater than our limit, then * we pause for up to 10ms, hoping that unlinkd * has some feedback for us. Maybe it just needs a slice * of the CPU's time. */ if (queuelen >= UNLINKD_QUEUE_LIMIT) xusleep(10000); /* * If there is at least one outstanding unlink request, then * try to read a response. If there's nothing to read we'll * get an EWOULDBLOCK or whatever. If we get a response, then * decrement the queue size by the number of newlines read. */ if (queuelen > 0) { int x; int i; char rbuf[512]; #ifdef _SQUID_MSWIN_ x = recv(unlinkd_rfd, rbuf, 511, 0); #else x = read(unlinkd_rfd, rbuf, 511); #endif if (x > 0) { rbuf[x] = '\0'; for (i = 0; i < x; i++) if ('\n' == rbuf[i]) queuelen--; assert(queuelen >= 0); } } l = strlen(path); assert(l < MAXPATHLEN); xstrncpy(buf, path, MAXPATHLEN); buf[l++] = '\n'; #ifdef _SQUID_MSWIN_ x = send(unlinkd_wfd, buf, l, 0); #else x = write(unlinkd_wfd, buf, l); #endif if (x < 0) { debug(2, 1) ("unlinkdUnlink: write FD %d failed: %s\n", unlinkd_wfd, xstrerror()); safeunlink(path, 0); return; } else if (x != l) { debug(2, 1) ("unlinkdUnlink: FD %d only wrote %d of %d bytes\n", unlinkd_wfd, x, l); safeunlink(path, 0); return; } statCounter.unlink.requests++; statCounter.syscalls.disk.unlinks++; queuelen++; } void unlinkdClose(void) { #ifdef _SQUID_MSWIN_ if (unlinkd_wfd > -1) { debug(2, 1) ("Closing unlinkd pipe on FD %d\n", unlinkd_wfd); shutdown(unlinkd_wfd, SD_BOTH); comm_close(unlinkd_wfd); if (unlinkd_wfd != unlinkd_rfd) comm_close(unlinkd_rfd); unlinkd_wfd = -1; unlinkd_rfd = -1; } else debug(2, 0) ("unlinkdClose: WARNING: unlinkd_wfd is %d\n", unlinkd_wfd); if (hIpc) { if (WaitForSingleObject(hIpc, 5000) != WAIT_OBJECT_0) { getCurrentTime(); debug(2, 1) ("unlinkdClose: WARNING: (unlinkd,%ld) didn't exit in 5 seconds\n", pid); } CloseHandle(hIpc); } #else if (unlinkd_wfd < 0) return; debug(2, 1) ("Closing unlinkd pipe on FD %d\n", unlinkd_wfd); file_close(unlinkd_wfd); if (unlinkd_wfd != unlinkd_rfd) file_close(unlinkd_rfd); unlinkd_wfd = -1; unlinkd_rfd = -1; #endif } void unlinkdInit(void) { const char *args[2]; struct timeval slp; args[0] = "(unlinkd)"; args[1] = NULL; #if (HAVE_POLL && defined(_SQUID_OSF_)) || defined(_SQUID_MSWIN_) /* pipes and poll() don't get along on DUNIX -DW */ /* On Windows select() will fail on a pipe */ pid = ipcCreate(IPC_STREAM, #else /* We currently need to use FIFO.. see below */ pid = ipcCreate(IPC_FIFO, #endif Config.Program.unlinkd, args, "unlinkd", &unlinkd_rfd, &unlinkd_wfd, &hIpc); if (pid < 0) fatal("Failed to create unlinkd subprocess"); slp.tv_sec = 0; slp.tv_usec = 250000; select(0, NULL, NULL, NULL, &slp); fd_note(unlinkd_wfd, "squid -> unlinkd"); fd_note(unlinkd_rfd, "unlinkd -> squid"); commSetTimeout(unlinkd_rfd, -1, NULL, NULL); commSetTimeout(unlinkd_wfd, -1, NULL, NULL); /* * unlinkd_rfd should already be non-blocking because of * ipcCreate. We change unlinkd_wfd to blocking mode because * we never want to lose an unlink request, and we don't have * code to retry if we get EWOULDBLOCK. Unfortunately, we can * do this only for the IPC_FIFO case. */ assert(fd_table[unlinkd_rfd].flags.nonblocking); if (FD_PIPE == fd_table[unlinkd_wfd].type) commUnsetNonBlocking(unlinkd_wfd); debug(2, 1) ("Unlinkd pipe opened on FD %d\n", unlinkd_wfd); } #endif /* ndef UNLINK_DAEMON */