ctl: fix alignment issue

If the provided input buffer is not aligned properly, the use of
message header won't work on structure not allowing unaligned access.

diff --git a/src/ctl.c b/src/ctl.c
index 937da07ef9766396fa069f06cae9533d22620221..12b35af81171bdc1649a9ad67ab75faad7bd0e04 100644 (file)
--- a/src/ctl.c
+++ b/src/ctl.c
@@ -198,7 +198,7 @@ ctl_msg_recv_unserialized(uint8_t **input_buffer, size_t *input_len,
     enum hmsg_type expected_type,
     void **t, struct marshal_info *mi)
 {
-       struct hmsg_header *hdr;
+       struct hmsg_header hdr;
        int rc = -1;
 
        if (*input_buffer == NULL ||
@@ -208,8 +208,8 @@ ctl_msg_recv_unserialized(uint8_t **input_buffer, size_t *input_len,
        }
 
        log_debug("control", "receive a message through control socket");
-       hdr = (struct hmsg_header *)*input_buffer;
-       if (hdr->len > HMSG_MAX_SIZE) {
+       memcpy(&hdr, *input_buffer, sizeof(struct hmsg_header));
+       if (hdr.len > HMSG_MAX_SIZE) {
                log_warnx("control", "message received is too large");
                /* We discard the whole buffer */
                free(*input_buffer);
@@ -217,25 +217,25 @@ ctl_msg_recv_unserialized(uint8_t **input_buffer, size_t *input_len,
                *input_len = 0;
                return -1;
        }
-       if (*input_len < sizeof(struct hmsg_header) + hdr->len) {
+       if (*input_len < sizeof(struct hmsg_header) + hdr.len) {
                /* Not enough data. */
-               return sizeof(struct hmsg_header) + hdr->len - *input_len;
+               return sizeof(struct hmsg_header) + hdr.len - *input_len;
        }
-       if (hdr->type != expected_type) {
+       if (hdr.type != expected_type) {
                if (expected_type == NOTIFICATION) return -1;
                log_warnx("control", "incorrect received message type (expected: %d, received: %d)",
-                   expected_type, hdr->type);
+                   expected_type, hdr.type);
                goto end;
        }
 
-       if (t && !hdr->len) {
+       if (t && !hdr.len) {
                log_warnx("control", "no payload available in answer");
                goto end;
        }
        if (t) {
                /* We have data to unserialize. */
                if (marshal_unserialize_(mi, *input_buffer + sizeof(struct hmsg_header),
-                       hdr->len, t, NULL, 0, 0) <= 0) {
+                       hdr.len, t, NULL, 0, 0) <= 0) {
                        log_warnx("control", "unable to deserialize received data");
                        goto end;
                }
@@ -244,13 +244,13 @@ ctl_msg_recv_unserialized(uint8_t **input_buffer, size_t *input_len,
        rc = 0;
 end:
        /* Discard input buffer */
-       *input_len -= sizeof(struct hmsg_header) + hdr->len;
+       *input_len -= sizeof(struct hmsg_header) + hdr.len;
        if (*input_len == 0) {
                free(*input_buffer);
                *input_buffer = NULL;
        } else
                memmove(*input_buffer,
-                   *input_buffer + sizeof(struct hmsg_header) + hdr->len,
+                   *input_buffer + sizeof(struct hmsg_header) + hdr.len,
                    *input_len);
        return rc;
 }