Merge branch 'release-4.16.1'

[i3/i3] / libi3 / ipc_recv_message.c

diff --git a/libi3/ipc_recv_message.c b/libi3/ipc_recv_message.c
index f5c4a62b69dc7ba8742ce1832b4e22422fcc05a3..84da5aa36cb90d7b913ec7c0afc87568102a9d70 100644 (file)
--- a/libi3/ipc_recv_message.c
+++ b/libi3/ipc_recv_message.c
@@ -2,75 +2,87 @@
  * vim:ts=4:sw=4:expandtab
  *
  * i3 - an improved dynamic tiling window manager
- * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
+ * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
  *
  */
+#include "libi3.h"
+
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <unistd.h>
+#include <errno.h>
+#include <inttypes.h>
 
 #include <i3/ipc.h>
 
-#include "libi3.h"
-
 /*
  * Reads a message from the given socket file descriptor and stores its length
  * (reply_length) as well as a pointer to its contents (reply).
  *
  * Returns -1 when read() fails, errno will remain.
- * Returns -2 when the IPC protocol is violated (invalid magic, unexpected
+ * Returns -2 on EOF.
+ * Returns -3 when the IPC protocol is violated (invalid magic, unexpected
  * message type, EOF instead of a message). Additionally, the error will be
  * printed to stderr.
  * Returns 0 on success.
  *
  */
-int ipc_recv_message(int sockfd, uint32_t message_type,
+int ipc_recv_message(int sockfd, uint32_t *message_type,
                      uint32_t *reply_length, uint8_t **reply) {
     /* Read the message header first */
-    uint32_t to_read = strlen(I3_IPC_MAGIC) + sizeof(uint32_t) + sizeof(uint32_t);
+    const uint32_t to_read = strlen(I3_IPC_MAGIC) + sizeof(uint32_t) + sizeof(uint32_t);
     char msg[to_read];
     char *walk = msg;
 
     uint32_t read_bytes = 0;
     while (read_bytes < to_read) {
-        int n = read(sockfd, msg + read_bytes, to_read);
+        int n = read(sockfd, msg + read_bytes, to_read - read_bytes);
         if (n == -1)
             return -1;
         if (n == 0) {
-            fprintf(stderr, "IPC: received EOF instead of reply\n");
-            return -2;
+            if (read_bytes == 0) {
+                return -2;
+            } else {
+                ELOG("IPC: unexpected EOF while reading header, got %" PRIu32 " bytes, want %" PRIu32 " bytes\n",
+                     read_bytes, to_read);
+                return -3;
+            }
         }
 
         read_bytes += n;
-        to_read -= n;
     }
 
     if (memcmp(walk, I3_IPC_MAGIC, strlen(I3_IPC_MAGIC)) != 0) {
-        fprintf(stderr, "IPC: invalid magic in reply\n");
-        return -2;
+        ELOG("IPC: invalid magic in header, got \"%.*s\", want \"%s\"\n",
+             (int)strlen(I3_IPC_MAGIC), walk, I3_IPC_MAGIC);
+        return -3;
     }
 
     walk += strlen(I3_IPC_MAGIC);
-    *reply_length = *((uint32_t*)walk);
+    memcpy(reply_length, walk, sizeof(uint32_t));
     walk += sizeof(uint32_t);
-    if (*((uint32_t*)walk) != message_type) {
-        fprintf(stderr, "IPC: unexpected reply type (got %d, expected %d)\n", *((uint32_t*)walk), message_type);
-        return -2;
-    }
+    if (message_type != NULL)
+        memcpy(message_type, walk, sizeof(uint32_t));
 
     *reply = smalloc(*reply_length);
 
-    to_read = *reply_length;
     read_bytes = 0;
-    while (read_bytes < to_read) {
-        int n = read(sockfd, *reply + read_bytes, to_read);
-        if (n == -1)
+    while (read_bytes < *reply_length) {
+        const int n = read(sockfd, *reply + read_bytes, *reply_length - read_bytes);
+        if (n == -1) {
+            if (errno == EINTR || errno == EAGAIN)
+                continue;
             return -1;
+        }
+        if (n == 0) {
+            ELOG("IPC: unexpected EOF while reading payload, got %" PRIu32 " bytes, want %" PRIu32 " bytes\n",
+                 read_bytes, *reply_length);
+            return -3;
+        }
 
         read_bytes += n;
-        to_read -= n;
     }
 
     return 0;