X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;ds=sidebyside;f=cprogs%2Fcgi-fcgi-interp.c;h=602ffa62d274a8165a95b3ee65dfed0a911c478b;hb=30e5907e11ada349dc2a63c1933067c0068b9c19;hp=9df31034aa8da607297ea67dff618b86c5c5e755;hpb=71eaa17c0ac8118db72b3ba7a24ad45345608694;p=chiark-utils.git

diff --git a/cprogs/cgi-fcgi-interp.c b/cprogs/cgi-fcgi-interp.c
index 9df3103..602ffa6 100644
--- a/cprogs/cgi-fcgi-interp.c
+++ b/cprogs/cgi-fcgi-interp.c
@@ -7,6 +7,7 @@
  * cgi-fcgi-interp.[ch] - C helpers common to the whole of chiark-utils
  *
  * Copyright 2016 Ian Jackson
+ * Copyright 1982,1986,1993 The Regents of the University of California
  *
  * 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
@@ -22,6 +23,8 @@
  * License along with this file; if not, consult the Free Software
  * Foundation's website at www.fsf.org, or the GNU Project website at
  * www.gnu.org.
+ *
+ * See below for a BSD 3-clause notice regarding timespeccmp.
  */
 /*
  * The result is a program which looks, when executed via the #!
@@ -47,6 +50,14 @@
  *         speedy, the specified number of servers is started
  *         right away.)  The default is 4.
  *
+ *  -c<interval>
+ *         Stale server check interval, in seconds.  The worker
+ *         process group will get a SIGTERM when it is no longer
+ *         needed to process new requests.  Ideally it would continue
+ *         to serve any existing requests.  The SIGTERM will arrive no
+ *         earlier than <interval> after the last request arrived at
+ *         the containing webserver.  Default is 300.
+ *
  *  -D
  *         Debug mode.  Do not actually run program.  Instead, print
  *         out what we would do.
@@ -65,7 +76,7 @@
  *   ~/.cgi-fcgi-interp/<node>/
  * and inside there uses these paths
  *   s<ident>
- *   g<inum>
+ *   l<ident>    used to lock around garbage collection
  *
  * If -M<ident> is not specified then an initial substricg of the
  * lowercase hex of the sha256 of the <script> (ie, our argv[1]) is
@@ -87,10 +98,22 @@
  *  - check for and maybe create <base>
  *  - stat and lstat the <script>
  *  - stat the socket and check its timestamp
- *       if it is too hold, rename it to g<inum> (where
- *       <inum> is in decimal)
- *       and run garbage collection
- *  - run  cgi-fcgi -connect SOCKET SCRIPT
+ *       if it is too old, unlink it
+ *  - dup2 stderr, mark no cloexec
+ *  - run     cgi-fcgi -connect SOCKET \
+ *                cgi-fcgi-interp -c<check-interval> \
+ *                --stage2 <was-stderr> <socket> \
+ *                <interp> <script>
+ *
+ * --stage2 does this:
+ *  - dup2 <was-stderr> to fd 2
+ *  - open /dev/null and expect fd 1 (and if not, close it)
+ *  - become a new process group
+ *  - lstat <socket> to find its inum, mtime
+ *  - fork/exec <interp> <script>
+ *  - periodically lstat <socket> and
+ *      if inum, mtime have changed
+ *      kill process group (at second iteration)
  */
 
 #include "common.h"
@@ -161,6 +184,7 @@ static const struct cmdinfo cmdinfos[]= {
 
 static uid_t us;
 static const char *run_base, *script, *socket_path;
+static struct stat sock_stab;
 
 static bool find_run_base_var_run(void) {
   struct stat stab;
@@ -264,10 +288,63 @@ static void find_socket_path(void) {
   socket_path = m_asprintf("%s/g%s",run_base,ident);
 }  
 
+/*
+ * Regarding the macro timespeccmp:
+ *
+ * Copyright (c) 1982, 1986, 1993
+ *      The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *      @(#)time.h      8.5 (Berkeley) 5/4/95
+ * $FreeBSD: head/sys/sys/time.h 275985 2014-12-21 05:07:11Z imp $
+ */
+#ifndef timespeccmp
+#define timespeccmp(tvp, uvp, cmp)                                      \
+        (((tvp)->tv_sec == (uvp)->tv_sec) ?                             \
+            ((tvp)->tv_nsec cmp (uvp)->tv_nsec) :                       \
+            ((tvp)->tv_sec cmp (uvp)->tv_sec))
+#endif /*timespeccmp*/
+
+
+
+static bool stab_isnewer(const struct stat *a, const struct stat *b) {
+#ifdef st_mtime
+  return timespeccmp(&a->st_mtim, &b->st_mtim, >);
+#else
+  return a->st_mtime > &b->st_mtime;
+#endif
+}
+
 static bool check_garbage(void) {
-  struct stat sock_stab, cmd_stab;
+  struct stat script_stab;
   int r;
 
+  r = lstat(script, &script_stab);
+  if (r) err(127,"lstat script (%s)",script);
+
   r = lstat(socket_path, &sock_stab);
   if (r) {
     if ((errno == ENOENT))
@@ -275,12 +352,79 @@ static bool check_garbage(void) {
     err(127,"stat socket (%s)",socket_path);
   }
 
-  r = lstat(script, &cmd_stab);
-  if (r) err(127,"lstat script (%s)",script);
+  if (stab_isnewer(&script_stab, &sock_stab))
+    return 1;
+
+  if (S_ISLNK(script_stab.st_mode)) {
+    r = stat(script, &script_stab);
+    if (r) err(127,"stat script (%s0",script);
+
+    if (stab_isnewer(&script_stab, &sock_stab))
+      return 1;
+  }
 
   return 0;
 }
 
+static void tidy_1_garbage(const char *leaf) {
+  int r;
+  struct sockaddr_un sun;
+
+  int fd = -1;
+
+  memset(&sun,0,sizeof(sun));
+  sun.sun_family = AF_UNIX;
+  r = snprintf(sun.sun_path, sizeof(sun.sun_path), "%s/%s", run_base, leaf);
+  if (r >= sizeof(sun_path))
+    goto cannot;
+
+  fd = socket(AF_UNIX, SOCK_STREAM, 0);
+  if (fd<0) err("create socket for tidying garbage");
+
+  r = fcntl(fd, F_SETFL, O_NONBLOCK);
+  if (r<0) err("set garbage socket nonblocking");
+
+  r = connect(fd, &sun, sizeof(sun));
+  if (r) {
+    if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
+      goto cannot;
+    if (errno != EINPROGRESS)
+      err("connect to garbage socket (%s)", sun.sun_path);
+    /* well, EINPROGRESS, let's just carry on and hope write works */
+  }
+
+  r = write(
+	
+
+static void tidy_garbage(void) {
+  const char *this_garbage =
+    m_asprintf("%s/g%lu.%lu", run_base,
+	       (unsigned long)sock_stab.st_ino,
+	       (unsigned long)getpid());
+
+  r = rename(socket_path, this_garbage);
+  if (r) {
+    if (!(errno == ENOENT))
+      err("rename socket from old runner (from %s to %s)",
+	  socket_path, this_garbage);
+  }
+
+  DIR *d = opendir(run_base);
+  if (!d) err("open run directory (%d) to clean up garbage", run_base);
+  struct dirent *de;
+  while ((errno = 0, de = readdir(d))) {
+    if (de->d_name[0] != 'g')
+      continue;
+    tidy_1_garbage(de->d_name);
+  }
+  if (errno) err("read run directory (%d) to clean up garbage", run_base);
+  /* 
+  (void)r;
+  if (r) {
+
+  printf("this_garb: %s\n", this_garbage);
+}
+
 static void shbang_opts(const char *const **argv_io,
 			const struct cmdinfo *cmdinfos) {
   myopt(argv_io, cmdinfos);
@@ -331,13 +475,18 @@ int main(int argc, const char *const *argv) {
 
   find_socket_path();
 
-  check_garbage();
+  bool havegarbage = check_garbage();
 
   if (debugmode) {
     printf("socket: %s\n",socket_path);
     printf("interp: %s\n",interp);
     printf("script: %s\n",script);
+    printf("garbage: %d\n",havegarbage);
+    exit(0);
   }
 
+  if (havegarbage)
+    tidy_garbage();
+
   exit(0);
 }