with a few exceptions, never return directly on failure, always goto fail by invoking fail_if

Signed-off-by: Mattias Andrée <maandree@operamail.com>

9 files changed, 93 insertions, 90 deletions

diff --git a/src/mds-server/interceptors.c b/src/mds-server/interceptors.c
index 6d798d9..8a24e33 100644
--- a/src/mds-server/interceptors.c
+++ b/src/mds-server/interceptors.c
@@ -140,19 +140,10 @@ void add_intercept_condition(client_t* client, char* condition, int64_t priority
   else
     {
       /* Duplicate condition string. */
-      if ((condition = strdup(condition)) == NULL)
-	{
-	  xperror(*argv);
-	  return;
-	}
+      fail_if ((condition = strdup(condition)) == NULL);
       
       /* Grow the interception condition list. */
-      if (xrealloc(conds, n + 1, interception_condition_t))
-	{
-	  xperror(*argv);
-	  free(condition);
-	  return;
-	}
+      fail_if (xrealloc(conds, n + 1, interception_condition_t));
       client->interception_conditions = conds; 
       /* Store condition. */
       client->interception_conditions_count++;
@@ -174,6 +165,12 @@ void add_intercept_condition(client_t* client, char* condition, int64_t priority
 	  conds[n] = temp;
 	}
     }
+  
+  return;
+ fail:
+  xperror(*argv);
+  free(condition);
+  return;
 }
 
 
@@ -220,9 +217,7 @@ int find_matching_condition(client_t* client, size_t* hashes, char** keys, char*
   interception_condition_t* conds = client->interception_conditions;
   size_t n = 0, i;
   
-  errno = pthread_mutex_lock(&(mutex));
-  if (errno)
-    return -1;
+  fail_if ((errno = pthread_mutex_lock(&(mutex))));
   
   /* Look for a matching condition. */
   if (client->open)
@@ -240,6 +235,8 @@ int find_matching_condition(client_t* client, size_t* hashes, char** keys, char*
   pthread_mutex_unlock(&(mutex));
   
   return i < n;
+ fail:
+  return -1;
 }
 
 
@@ -252,23 +249,22 @@ int find_matching_condition(client_t* client, size_t* hashes, char** keys, char*
  * @param   headers                  The header name–value pairs
  * @param   count                    The number of accepted patterns
  * @param   interceptions_count_out  Slot at where to store the number of found interceptors
- * @return                           The found interceptors, NULL on error
+ * @return                           The found interceptors, `NULL` on error
  */
 queued_interception_t* get_interceptors(client_t* sender, size_t* hashes, char** keys, char** headers,
 					size_t count, size_t* interceptions_count_out)
 {
   queued_interception_t* interceptions = NULL;
-  size_t interceptions_count = 0;
-  size_t n = 0;
+  size_t interceptions_count = 0, n = 0;
   ssize_t node;
+  int saved_errno;
   
   /* Count clients. */
   foreach_linked_list_node (client_list, node)
     n++;
   
   /* Allocate interceptor list. */
-  if (xmalloc(interceptions, n, queued_interception_t))
-    return NULL;
+  fail_if (xmalloc(interceptions, n, queued_interception_t));
   
   /* Search clients. */
   foreach_linked_list_node (client_list, node)
@@ -280,11 +276,7 @@ queued_interception_t* get_interceptors(client_t* sender, size_t* hashes, char**
 	{
 	  int r = find_matching_condition(client, hashes, keys, headers, count,
 					  interceptions + interceptions_count);
-	  if (r == -1)
-	    {
-	      free(interceptions);
-	      return NULL;
-	    }
+	  fail_if (r == -1);
 	  if (r)
 	    /* List client of there was a matching condition. */
 	    interceptions_count++;
@@ -293,5 +285,10 @@ queued_interception_t* get_interceptors(client_t* sender, size_t* hashes, char**
   
   *interceptions_count_out = interceptions_count;
   return interceptions;
+  
+ fail:
+  saved_errno = errno;
+  free(interceptions);
+  return errno = saved_errno, NULL;
 }
 
diff --git a/src/mds-server/interceptors.h b/src/mds-server/interceptors.h
index 7bb60e5..e2e6041 100644
--- a/src/mds-server/interceptors.h
+++ b/src/mds-server/interceptors.h
@@ -77,7 +77,7 @@ int find_matching_condition(client_t* client, size_t* hashes, char** keys, char*
  * @param   headers                  The header name–value pairs
  * @param   count                    The number of accepted patterns
  * @param   interceptions_count_out  Slot at where to store the number of found interceptors
- * @return                           The found interceptors, NULL on error
+ * @return                           The found interceptors, `NULL` on error
  */
 queued_interception_t* get_interceptors(client_t* sender, size_t* hashes, char** keys, char** headers,
 					size_t count, size_t* interceptions_count_out);
diff --git a/src/mds-server/mds-server.c b/src/mds-server/mds-server.c
index 8ef44cc..fabdffa 100644
--- a/src/mds-server/mds-server.c
+++ b/src/mds-server/mds-server.c
@@ -130,8 +130,7 @@ int preinitialise_server(void)
 	  close_files((fd > 2) || (fd == socket_fd));
 	  
 	  /* Run mdsinitrc. */
-	  run_initrc(unparsed_args);
-	  return 1;
+	  run_initrc(unparsed_args); /* Does not return. */
 	}
     }
   
@@ -408,11 +407,8 @@ void queue_message_multicast(char* message, size_t length, client_t* sender)
   /* Count the number of headers. */
   for (i = 0; i < n; i++)
     if (message[i] == '\n')
-      {
-	header_count++;
-	if (message[i + 1] == '\n')
-	  break;
-      }
+      if (header_count++, message[i + 1] == '\n')
+	break;
   
   if (header_count == 0)
     return; /* Invalid message. */
@@ -583,5 +579,7 @@ void run_initrc(char** args)
   
   /* Everything failed. */
   eprintf("unable to run %s file, you might as well kill me.", INITRC_FILE);
+  /* (‘me’ actually refers to the parant, whence it will to be coming.) */
+  exit(0);
 }
 
diff --git a/src/mds-server/mds-server.h b/src/mds-server/mds-server.h
index 4d6c5e7..4624761 100644
--- a/src/mds-server/mds-server.h
+++ b/src/mds-server/mds-server.h
@@ -53,7 +53,7 @@ void queue_message_multicast(char* message, size_t length, client_t* sender);
  * 
  * @param  args  The arguments to the child process
  */
-void run_initrc(char** args);
+void run_initrc(char** args) __attribute__((noreturn));
 
 
 #endif
diff --git a/src/mds-server/receiving.c b/src/mds-server/receiving.c
index 71f1210..8571944 100644
--- a/src/mds-server/receiving.c
+++ b/src/mds-server/receiving.c
@@ -116,14 +116,13 @@ static int modifying_notify(client_t* client, mds_message_t message, uint64_t mo
  */
 static int add_intercept_conditions_from_message(client_t* client, int modifying, int64_t priority, int stop)
 {
-  int errno_ = 0;
+  int saved_errno;
   char* payload = client->message.payload;
   size_t payload_size = client->message.payload_size;
   size_t size = 64;
   char* buf;
   
-  if (xmalloc(buf, size + 1, char))
-    return -1;
+  fail_if (xmalloc(buf, size + 1, char));
   
   /* All messages */
   if (client->message.payload_size == 0)
@@ -149,10 +148,10 @@ static int add_intercept_conditions_from_message(client_t* client, int modifying
 	  char* old_buf = buf;
 	  if (xrealloc(buf, (size <<= 1) + 1, char))
 	    {
-	      errno_ = errno;
+	      saved_errno = errno;
 	      free(old_buf);
 	      pthread_mutex_unlock(&(client->mutex));
-	      break;
+	      fail_if (errno = saved_errno, 1);
 	    }
 	}
       memcpy(buf, payload, len);
@@ -166,8 +165,9 @@ static int add_intercept_conditions_from_message(client_t* client, int modifying
   
  done:
   free(buf);
-  errno = errno_;
-  return errno_ ? -1 : 0;
+  return 0;
+ fail:
+  return -1;
 }
 
 
diff --git a/src/mds-server/reexec.c b/src/mds-server/reexec.c
index 981569e..fe8c196 100644
--- a/src/mds-server/reexec.c
+++ b/src/mds-server/reexec.c
@@ -179,15 +179,13 @@ int unmarshal_server(char* state_buf)
   ssize_t node;
   pthread_t slave_thread;
   
-  
+#define fail  soft_fail
+
   /* Create memory address remapping table. */
-  if (hash_table_create(&unmarshal_remap_map))
-    {
-      xperror(*argv);
-      hash_table_destroy(&unmarshal_remap_map, NULL, NULL);
-      return -1;
-    }
-  
+  fail_if (hash_table_create(&unmarshal_remap_map));
+
+#undef fail
+#define fail  clients_fail
   
   /* Get the marshal protocal version. Not needed, there is only the one version right now. */
   /* buf_get(state_buf, int, 0, MDS_SERVER_VARS_VERSION); */
@@ -210,20 +208,16 @@ int unmarshal_server(char* state_buf)
       client_t* value;
       
       /* Allocate the client's information. */
-      if (xmalloc(value, 1, client_t))
-	goto clients_fail;
+      fail_if (xmalloc(value, 1, client_t));
       
       /* Unmarshal the address, it is used the the client list and the client map, that are also marshalled. */
       buf_get_next(state_buf, size_t, value_address);
       /* Unmarshal the client information. */
-      n = client_unmarshal(value, state_buf);
-      if (n == 0)
-	goto clients_fail;
+      fail_if (n = client_unmarshal(value, state_buf), n == 0);
       
       /* Populate the remapping table. */
       if (hash_table_put(&unmarshal_remap_map, value_address, (size_t)(void*)value) == 0)
-	if (errno)
-	  goto clients_fail;
+	fail_if (errno);
       
       /* Delayed seeking. */
       state_buf += n / sizeof(char);
@@ -247,14 +241,15 @@ int unmarshal_server(char* state_buf)
       break;
     }
   
+#undef fail
+#define fail  critical_fail
+  
   /* Unmarshal the client list. */
-  if (linked_list_unmarshal(&client_list, state_buf))
-    goto critical_fail;
+  fail_if (linked_list_unmarshal(&client_list, state_buf));
   state_buf += list_size / sizeof(char);
   
   /* Unmarshal the client map. */
-  if (fd_table_unmarshal(&client_map, state_buf, unmarshal_remapper))
-    goto critical_fail;
+  fail_if (fd_table_unmarshal(&client_map, state_buf, unmarshal_remapper));
   
   /* Remove non-found elements from the fd table. */
 #define __bit(I, _OP_)  client_map.used[I / 64] _OP_ ((uint64_t)1 << (I % 64))
@@ -291,8 +286,12 @@ int unmarshal_server(char* state_buf)
   hash_table_destroy(&unmarshal_remap_map, NULL, NULL);
   
   return with_error;
+#undef fail
   
-  
+ soft_fail:
+  xperror(*argv);
+  hash_table_destroy(&unmarshal_remap_map, NULL, NULL);
+  return -1;
  critical_fail:
   xperror(*argv);
   abort();
diff --git a/src/mds-server/slavery.c b/src/mds-server/slavery.c
index 7ff801d..cf5e45d 100644
--- a/src/mds-server/slavery.c
+++ b/src/mds-server/slavery.c
@@ -47,11 +47,15 @@ void* slave_loop(void*);
 int fetch_message(client_t* client)
 {
   int r = mds_message_read(&(client->message), client->socket_fd);
+  
   if (r == 0)
     return 0;
   
   if (r == -2)
-    eprint("corrupt message received.");
+    {
+      eprint("corrupt message received.");
+      fail_if (1);
+    }
   else if (errno == ECONNRESET)
     {
       r = mds_message_read(&(client->message), client->socket_fd);
@@ -60,11 +64,14 @@ int fetch_message(client_t* client)
     }
   else if (errno != EINTR)
     {
-      r = -2;
       xperror(*argv);
+      fail_if (1);
     }
   
+  fail_if (r == -2);
   return r;
+ fail:
+  return -2;
 }
 
 
@@ -81,14 +88,16 @@ int create_slave(pthread_t* thread_slot, int slave_fd)
     {
       xperror(*argv);
       with_mutex (slave_mutex, running_slaves--;);
-      return -1;
+      fail_if (1);
     }
   if ((errno = pthread_detach(*thread_slot)))
     {
       xperror(*argv);
-      return -1;
+      fail_if (1);
     }
   return 0;
+ fail:
+  return -1;
 }
 
 
@@ -96,7 +105,7 @@ int create_slave(pthread_t* thread_slot, int slave_fd)
  * Initialise a client, except for threading
  * 
  * @param   client_fd  The file descriptor of the client's socket
- * @return             The client information, NULL on error
+ * @return             The client information, `NULL` on error
  */
 client_t* initialise_client(int client_fd)
 {
diff --git a/src/mds-server/slavery.h b/src/mds-server/slavery.h
index 92144fd..00f6084 100644
--- a/src/mds-server/slavery.h
+++ b/src/mds-server/slavery.h
@@ -45,7 +45,7 @@ int create_slave(pthread_t* thread_slot, int slave_fd);
  * Initialise a client, except for threading
  * 
  * @param   client_fd  The file descriptor of the client's socket
- * @return             The client information, NULL on error
+ * @return             The client information, `NULL` on error
  */
 client_t* initialise_client(int client_fd);
 
diff --git a/src/mds.c b/src/mds.c
index bad0060..8dce0d1 100644
--- a/src/mds.c
+++ b/src/mds.c
@@ -73,7 +73,7 @@ int main(int argc_, char** argv_)
   struct sockaddr_un address;
   char pathname[PATH_MAX];
   char piddata[64];
-  unsigned int display;
+  unsigned int display = DISPLAY_MAX;
   FILE* f;
   int rc;
   int j, r;
@@ -116,8 +116,7 @@ int main(int argc_, char** argv_)
   saved_umask = umask(0);
   
   /* Create directory for socket files, PID files and such. */
-  if (create_directory_root(MDS_RUNTIME_ROOT_DIRECTORY))
-    return 1;
+  fail_if (create_directory_root(MDS_RUNTIME_ROOT_DIRECTORY));
   
   
   /* Determine display index. */
@@ -148,14 +147,12 @@ int main(int argc_, char** argv_)
            /* Yes, the directory could have been removed, but it probably was not. */
   
   /* Create PID file. */
-  fail_if ((f = fopen(pathname, "w")) == NULL);
+  fail_if (f = fopen(pathname, "w"), f == NULL);
   xsnprintf(piddata, "%u\n", getpid());
   if (fwrite(piddata, 1, strlen(piddata), f) < strlen(piddata))
     {
       fclose(f);
-      if (unlink(pathname) < 0)
-	xperror(*argv);
-      return 1;
+      fail_if (1);
     }
   fflush(f);
   fclose(f);
@@ -205,6 +202,9 @@ int main(int argc_, char** argv_)
       unlink(pathname);
     }
   
+  if (display == DISPLAY_MAX)
+    return rc;
+  
   /* Remove PID file. */
   xsnprintf(pathname, "%s/%u.pid", MDS_RUNTIME_ROOT_DIRECTORY, display);
   unlink(pathname);
@@ -236,9 +236,8 @@ int is_pid_file_reusable(FILE* f)
   size_t read_len;
   
   read_len = fread(piddata, 1, sizeof(piddata) / sizeof(char), f);
-  if (ferror(f)) /* Failed to read. */
-    xperror(*argv);
-  else if (feof(f) == 0) /* Did not read everything. */
+  fail_if (ferror(f)); /* Failed to read. */
+  if (feof(f) == 0) /* Did not read everything. */
     eprint("the content of a PID file is larger than expected.");
   else
     {
@@ -251,6 +250,9 @@ int is_pid_file_reusable(FILE* f)
     }
   
   return 0;
+ fail:
+  xperror(*argv);
+  return 0;
 }
 
 
@@ -293,11 +295,13 @@ static void exec_master_server(char** child_args)
 {
   /* Drop privileges. They most not be propagated non-authorised components. */
   /* setgid should not be set, but just to be safe we are restoring both user and group. */
-  if (drop_privileges())
-    return;
+  fail_if (drop_privileges());
   
   /* Start master server. */
   execv(master_server, child_args);
+  fail_if (1);
+ fail:
+  return;
 }
 
 
@@ -442,7 +446,8 @@ int create_directory_root(const char* pathname)
     /* Directory is missing, create it. */
     if (mkdir(pathname, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) < 0)
       {
-	fail_if (errno != EEXIST); /* Unlikely race condition. */
+	/* Unlikely race condition. */
+	fail_if (errno != EEXIST);
       }
     else
       {
@@ -451,7 +456,6 @@ int create_directory_root(const char* pathname)
       }
   
   return 0;
-
  fail:
   xperror(*argv);
   return 1;
@@ -483,22 +487,18 @@ int create_directory_user(const char* pathname)
       /* Directory is missing, create it. */
       if (mkdir(pathname, S_IRWXU) < 0)
 	{
-	  if (errno != EEXIST) /* Unlikely race condition. */
-	    {
-	      xperror(*argv);
-	      return 1;
-	    }
+	  /* Unlikely race condition. */
+	  fail_if (errno != EEXIST);
 	}
       else
 	/* Set ownership. */
-	if (chown(pathname, getuid(), NOBODY_GROUP_GID) < 0)
-	  {
-	    xperror(*argv);
-	    return 1;
-	  }
+	fail_if (chown(pathname, getuid(), NOBODY_GROUP_GID) < 0);
     }
   
   return 0;
+ fail:
+  xperror(*argv);
+  return 1;
 }