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ipc_recv_message: store message_type, don’t compare. add distinct EOF retval

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Also use ELOG, which requires i3-msg to provide logging functions.
This commit is contained in:
Michael Stapelberg
2013-01-23 18:50:21 +01:00
parent e8fa3eeebd
commit dcb8ac84f8
5 changed files with 53 additions and 25 deletions
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36
libi3/ipc_recv_message.c
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@ -2,7 +2,7 @@
* vim:ts=4:sw=4:expandtab
*
* i3 - an improved dynamic tiling window manager
* © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
* © 2009-2013 Michael Stapelberg and contributors (see also: LICENSE)
*
*/
#include <string.h>
@ -10,6 +10,7 @@
#include <stdio.h>
#include <stdint.h>
#include <unistd.h>
#include <errno.h>
#include <i3/ipc.h>
@ -20,57 +21,56 @@
* (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");
ELOG("IPC: received EOF instead of reply\n");
return -2;
}
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 reply\n");
return -3;
}
walk += strlen(I3_IPC_MAGIC);
*reply_length = *((uint32_t*)walk);
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)
*message_type = *((uint32_t*)walk);
*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)
int n;
while (read_bytes < *reply_length) {
if ((n = read(sockfd, *reply + read_bytes, *reply_length - read_bytes)) == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
return -1;
}
read_bytes += n;
to_read -= n;
}
return 0;