X-Git-Url: http://git.ipfire.org/?a=blobdiff_plain;f=src%2Finotify.c;h=f3e5c3d1689f1e66a95bce7e702c62b805ae8bf6;hb=362c9303da25640ce8e73ee0b2902005f862c84f;hp=818fe8eddda47bf2b2c7a548a6066a1675de3933;hpb=0491805d2ff6e7727f0272c94fd97d9897d1e22c;p=people%2Fms%2Fdnsmasq.git

diff --git a/src/inotify.c b/src/inotify.c
index 818fe8e..f3e5c3d 100644
--- a/src/inotify.c
+++ b/src/inotify.c
@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2014 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2015 Simon Kelley
  
    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
@@ -18,11 +18,7 @@
 #ifdef HAVE_INOTIFY
 
 #include <sys/inotify.h>
-
-#ifdef HAVE_DHCP
-static void check_for_dhcp_inotify(struct inotify_event *in, time_t now);
-#endif
-
+#include <sys/param.h> /* For MAXSYMLINKS */
 
 /* the strategy is to set a inotify on the directories containing
    resolv files, for any files in the directory which are close-write 
@@ -40,10 +36,56 @@ static void check_for_dhcp_inotify(struct inotify_event *in, time_t now);
 static char *inotify_buffer;
 #define INOTIFY_SZ (sizeof(struct inotify_event) + NAME_MAX + 1)
 
+/* If path is a symbolic link, return the path it
+   points to, made absolute if relative.
+   If path doesn't exist or is not a symlink, return NULL.
+   Return value is malloc'ed */
+static char *my_readlink(char *path)
+{
+  ssize_t rc;
+  size_t size = 64;
+  char *buf;
+
+  while (1)
+    {
+      buf = safe_malloc(size);
+      rc = readlink(path, buf, size);
+      
+      if (rc == -1)
+	{
+	  /* Not link or doesn't exist. */
+	  if (errno == EINVAL || errno == ENOENT)
+	    return NULL;
+	  else
+	    die(_("cannot access path %s: %s"), path, EC_MISC);
+	}
+      else if (rc < size-1)
+	{
+	  char *d;
+	  
+	  buf[rc] = 0;
+	  if (buf[0] != '/' && ((d = strrchr(path, '/'))))
+	    {
+	      /* Add path to relative link */
+	      char *new_buf = safe_malloc((d - path) + strlen(buf) + 2);
+	      *(d+1) = 0;
+	      strcpy(new_buf, path);
+	      strcat(new_buf, buf);
+	      free(buf);
+	      buf = new_buf;
+	    }
+	  return buf;
+	}
+
+      /* Buffer too small, increase and retry */
+      size += 64;
+      free(buf);
+    }
+}
+
 void inotify_dnsmasq_init()
 {
   struct resolvc *res;
-
   inotify_buffer = safe_malloc(INOTIFY_SZ);
   daemon->inotifyfd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
   
@@ -52,19 +94,22 @@ void inotify_dnsmasq_init()
   
   for (res = daemon->resolv_files; res; res = res->next)
     {
-      char *d = NULL, *path;
-      
-      if (!(path = realpath(res->name, NULL)))
+      char *d, *new_path, *path = safe_malloc(strlen(res->name) + 1);
+      int links = MAXSYMLINKS;
+
+      strcpy(path, res->name);
+
+      /* Follow symlinks until we reach a non-symlink, or a non-existant file. */
+      while ((new_path = my_readlink(path)))
 	{
-	  /* realpath will fail if the file doesn't exist, but
-	     dnsmasq copes with missing files, so fall back 
-	     and assume that symlinks are not in use in that case. */
-	  if (errno == ENOENT)
-	    path = res->name;
-	  else
-	    die(_("cannot cannonicalise resolv-file %s: %s"), res->name, EC_MISC); 
+	  if (links-- == 0)
+	    die(_("too many symlinks following %s"), res->name, EC_MISC);
+	  free(path);
+	  path = new_path;
 	}
-      
+
+      res->wd = -1;
+
       if ((d = strrchr(path, '/')))
 	{
 	  *d = 0; /* make path just directory */
@@ -75,74 +120,48 @@ void inotify_dnsmasq_init()
 	  
 	  if (res->wd == -1 && errno == ENOENT)
 	    die(_("directory %s for resolv-file is missing, cannot poll"), res->name, EC_MISC);
-	  
-	  if (res->wd == -1)
-	    die(_("failed to create inotify for %s: %s"), res->name, EC_MISC);
-	}
+	}	  
+	 
+      if (res->wd == -1)
+	die(_("failed to create inotify for %s: %s"), res->name, EC_MISC);
+	
     }
 }
 
-int inotify_check(time_t now)
+
+/* initialisation for dynamic-dir. Set inotify watch for each directory, and read pre-existing files */
+void set_dynamic_inotify(int flag, int total_size, struct crec **rhash, int revhashsz)
 {
-  int hit = 0;
+  struct hostsfile *ah;
   
-  while (1)
+  for (ah = daemon->dynamic_dirs; ah; ah = ah->next)
     {
-      int rc;
-      char *p;
-      struct resolvc *res;
-      struct inotify_event *in;
-
-      while ((rc = read(daemon->inotifyfd, inotify_buffer, INOTIFY_SZ)) == -1 && errno == EINTR);
-      
-      if (rc <= 0)
-	break;
-      
-      for (p = inotify_buffer; rc - (p - inotify_buffer) >= (int)sizeof(struct inotify_event); p += sizeof(struct inotify_event) + in->len) 
+      DIR *dir_stream = NULL;
+      struct dirent *ent;
+      struct stat buf;
+     
+      if (!(ah->flags & flag))
+	continue;
+ 
+      if (stat(ah->fname, &buf) == -1 || !(S_ISDIR(buf.st_mode)))
 	{
-	  in = (struct inotify_event*)p;
-	  
-	  for (res = daemon->resolv_files; res; res = res->next)
-	    if (res->wd == in->wd && in->len != 0 && strcmp(res->file, in->name) == 0)
-	      hit = 1;
-
-#ifdef HAVE_DHCP
-	  if (daemon->dhcp || daemon->doing_dhcp6)
-	    check_for_dhcp_inotify(in, now);
-#endif
+	  my_syslog(LOG_ERR, _("bad dynamic directory %s: %s"), 
+		    ah->fname, strerror(errno));
+	  continue;
 	}
-    }
-  return hit;
-}
-
-#ifdef HAVE_DHCP 
-/* initialisation for dhcp-hostdir. Set inotify watch for each directory, and read pre-existing files */
-void set_dhcp_inotify(void)
-{
-  struct hostsfile *ah;
-
-  for (ah = daemon->inotify_hosts; ah; ah = ah->next)
-    {
-       DIR *dir_stream = NULL;
-       struct dirent *ent;
-       struct stat buf;
-
-       if (stat(ah->fname, &buf) == -1 || !(S_ISDIR(buf.st_mode)))
-	 {
-	   my_syslog(LOG_ERR, _("bad directory in dhcp-hostsdir %s"), ah->fname);
-	   continue;
-	 }
-
+      
        if (!(ah->flags & AH_WD_DONE))
 	 {
 	   ah->wd = inotify_add_watch(daemon->inotifyfd, ah->fname, IN_CLOSE_WRITE | IN_MOVED_TO);
 	   ah->flags |= AH_WD_DONE;
 	 }
-       /* Read contents of dir _after_ calling add_watch, in the ho[e of avoiding
+
+       /* Read contents of dir _after_ calling add_watch, in the hope of avoiding
 	  a race which misses files being added as we start */
        if (ah->wd == -1 || !(dir_stream = opendir(ah->fname)))
 	 {
-	   my_syslog(LOG_ERR, _("failed to create inotify for %s"), ah->fname);
+	   my_syslog(LOG_ERR, _("failed to create inotify for %s: %s"),
+		     ah->fname, strerror(errno));
 	   continue;
 	 }
 
@@ -167,54 +186,104 @@ void set_dhcp_inotify(void)
 	       
 	       /* ignore non-regular files */
 	       if (stat(path, &buf) != -1 && S_ISREG(buf.st_mode))
-		 option_read_hostsfile(path);
-	       
+		 {
+		   if (ah->flags & AH_HOSTS)
+		     total_size = read_hostsfile(path, ah->index, total_size, rhash, revhashsz);
+#ifdef HAVE_DHCP
+		   else if (ah->flags & (AH_DHCP_HST | AH_DHCP_OPT))
+		     option_read_dynfile(path, ah->flags);
+#endif		   
+		 }
+
 	       free(path);
 	     }
 	 }
     }
 }
 
-static void check_for_dhcp_inotify(struct inotify_event *in, time_t now)
+int inotify_check(time_t now)
 {
+  int hit = 0;
   struct hostsfile *ah;
 
-  /* ignore emacs backups and dotfiles */
-  if (in->len == 0 || 
-      in->name[in->len - 1] == '~' ||
-      (in->name[0] == '#' && in->name[in->len - 1] == '#') ||
-      in->name[0] == '.')
-    return;
-
-  for (ah = daemon->inotify_hosts; ah; ah = ah->next)
-    if (ah->wd == in->wd)
-      {
-	size_t lendir = strlen(ah->fname);
-	char *path;
-	   
-	if ((path = whine_malloc(lendir + in->len + 2)))
-	  {
-	    strcpy(path, ah->fname);
-	    strcat(path, "/");
-	    strcat(path, in->name);
-	    
-	    if (option_read_hostsfile(path))
+  while (1)
+    {
+      int rc;
+      char *p;
+      struct resolvc *res;
+      struct inotify_event *in;
+
+      while ((rc = read(daemon->inotifyfd, inotify_buffer, INOTIFY_SZ)) == -1 && errno == EINTR);
+      
+      if (rc <= 0)
+	break;
+      
+      for (p = inotify_buffer; rc - (p - inotify_buffer) >= (int)sizeof(struct inotify_event); p += sizeof(struct inotify_event) + in->len) 
+	{
+	  in = (struct inotify_event*)p;
+	  
+	  for (res = daemon->resolv_files; res; res = res->next)
+	    if (res->wd == in->wd && in->len != 0 && strcmp(res->file, in->name) == 0)
+	      hit = 1;
+
+	  /* ignore emacs backups and dotfiles */
+	  if (in->len == 0 || 
+	      in->name[in->len - 1] == '~' ||
+	      (in->name[0] == '#' && in->name[in->len - 1] == '#') ||
+	      in->name[0] == '.')
+	    continue;
+	  
+	  for (ah = daemon->dynamic_dirs; ah; ah = ah->next)
+	    if (ah->wd == in->wd)
 	      {
-		/* Propogate the consequences of loading a new dhcp-host */
-		dhcp_update_configs(daemon->dhcp_conf);
-		lease_update_from_configs(); 
-		lease_update_file(now); 
-		lease_update_dns(1);
+		size_t lendir = strlen(ah->fname);
+		char *path;
+		
+		if ((path = whine_malloc(lendir + in->len + 2)))
+		  {
+		    strcpy(path, ah->fname);
+		    strcat(path, "/");
+		    strcat(path, in->name);
+		     
+		    my_syslog(LOG_INFO, _("inotify, new or changed file %s"), path);
+
+		    if (ah->flags & AH_HOSTS)
+		      {
+			read_hostsfile(path, ah->index, 0, NULL, 0);
+#ifdef HAVE_DHCP
+			if (daemon->dhcp || daemon->doing_dhcp6) 
+			  {
+			    /* Propogate the consequences of loading a new dhcp-host */
+			    dhcp_update_configs(daemon->dhcp_conf);
+			    lease_update_from_configs(); 
+			    lease_update_file(now); 
+			    lease_update_dns(1);
+			  }
+#endif
+		      }
+#ifdef HAVE_DHCP
+		    else if (ah->flags & AH_DHCP_HST)
+		      {
+			if (option_read_dynfile(path, AH_DHCP_HST))
+			  {
+			    /* Propogate the consequences of loading a new dhcp-host */
+			    dhcp_update_configs(daemon->dhcp_conf);
+			    lease_update_from_configs(); 
+			    lease_update_file(now); 
+			    lease_update_dns(1);
+			  }
+		      }
+		    else if (ah->flags & AH_DHCP_OPT)
+		      option_read_dynfile(path, AH_DHCP_OPT);
+#endif
+		    
+		    free(path);
+		  }
 	      }
-	    
-	    free(path);
-	  }
-	
-	return;
-      }
+	}
+    }
+  return hit;
 }
 
-#endif /* DHCP */
-
 #endif  /* INOTIFY */