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