/*
* vim:ts=4:sw=4:expandtab
*
* i3 - an improved dynamic tiling window manager
* © 2009 Michael Stapelberg and contributors (see also: LICENSE)
*
* i3-dump-log/main.c: Dumps the i3 SHM log to stdout.
*
*/
#include <config.h>
#include "libi3.h"
#include "shmlog.h"
#include <err.h>
#include <fcntl.h>
#include <getopt.h>
#include <i3/ipc.h>
#include <signal.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
static uint32_t wrap_count;
static i3_shmlog_header *header;
static char *logbuffer,
*walk;
static int ipcfd = -1;
static void disable_shmlog(void) {
const char *disablecmd = "debuglog off; shmlog off";
if (ipc_send_message(ipcfd, strlen(disablecmd),
I3_IPC_MESSAGE_TYPE_COMMAND, (uint8_t *)disablecmd) != 0)
err(EXIT_FAILURE, "IPC send");
/* Ensure the command was sent by waiting for the reply: */
uint32_t reply_length = 0;
uint8_t *reply = NULL;
if (ipc_recv_message(ipcfd, I3_IPC_REPLY_TYPE_COMMAND,
&reply_length, &reply) != 0) {
err(EXIT_FAILURE, "IPC recv");
}
free(reply);
}
static int check_for_wrap(void) {
if (wrap_count == header->wrap_count)
return 0;
/* The log wrapped. Print the remaining content and reset walk to the top
* of the log. */
wrap_count = header->wrap_count;
const int len = (logbuffer + header->offset_last_wrap) - walk;
swrite(STDOUT_FILENO, walk, len);
walk = logbuffer + sizeof(i3_shmlog_header);
return 1;
}
static void print_till_end(void) {
check_for_wrap();
const int len = (logbuffer + header->offset_next_write) - walk;
swrite(STDOUT_FILENO, walk, len);
walk += len;
}
void errorlog(char *fmt, ...) {
va_list args;
va_start(args, fmt);
vfprintf(stderr, fmt, args);
va_end(args);
}
int main(int argc, char *argv[]) {
int o, option_index = 0;
bool verbose = false;
#if !defined(__OpenBSD__)
bool follow = false;
#endif
static struct option long_options[] = {
{"version", no_argument, 0, 'v'},
{"verbose", no_argument, 0, 'V'},
#if !defined(__OpenBSD__)
{"follow", no_argument, 0, 'f'},
#endif
{"help", no_argument, 0, 'h'},
{0, 0, 0, 0}
};
#if !defined(__OpenBSD__)
char *options_string = "s:vfVh";
#else
char *options_string = "vVh";
#endif
while ((o = getopt_long(argc, argv, options_string, long_options, &option_index)) != -1) {
if (o == 'v') {
printf("i3-dump-log " I3_VERSION "\n");
return 0;
} else if (o == 'V') {
verbose = true;
#if !defined(__OpenBSD__)
} else if (o == 'f') {
follow = true;
#endif
} else if (o == 'h') {
printf("i3-dump-log " I3_VERSION "\n");
#if !defined(__OpenBSD__)
printf("i3-dump-log [-fhVv]\n");
#else
printf("i3-dump-log [-hVv]\n");
#endif
return 0;
}
}
char *shmname = root_atom_contents("I3_SHMLOG_PATH", NULL, 0);
if (shmname == NULL) {
/* Something failed. Let’s invest a little effort to find out what it
* is. This is hugely helpful for users who want to debug i3 but are
* not used to the procedure yet. */
xcb_connection_t *conn;
int screen;
if ((conn = xcb_connect(NULL, &screen)) == NULL ||
xcb_connection_has_error(conn)) {
fprintf(stderr, "i3-dump-log: ERROR: Cannot connect to X11.\n\n");
if (getenv("DISPLAY") == NULL) {
fprintf(stderr, "Your DISPLAY environment variable is not set.\n");
fprintf(stderr, "Are you running i3-dump-log via SSH or on a virtual console?\n");
fprintf(stderr, "Try DISPLAY=:0 i3-dump-log\n");
exit(1);
}
fprintf(stderr, "FYI: The DISPLAY environment variable is set to \"%s\".\n", getenv("DISPLAY"));
exit(1);
}
if (root_atom_contents("I3_CONFIG_PATH", conn, screen) != NULL) {
fprintf(stderr, "i3-dump-log: i3 is running, but SHM logging is not enabled. Enabling SHM log now while i3-dump-log is running\n\n");
ipcfd = ipc_connect(NULL);
const char *enablecmd = "debuglog on; shmlog 5242880";
if (ipc_send_message(ipcfd, strlen(enablecmd),
I3_IPC_MESSAGE_TYPE_COMMAND, (uint8_t *)enablecmd) != 0)
err(EXIT_FAILURE, "IPC send");
/* By the time we receive a reply, I3_SHMLOG_PATH is set: */
uint32_t reply_length = 0;
uint8_t *reply = NULL;
if (ipc_recv_message(ipcfd, I3_IPC_REPLY_TYPE_COMMAND,
&reply_length, &reply) != 0) {
err(EXIT_FAILURE, "IPC recv");
}
free(reply);
atexit(disable_shmlog);
/* Retry: */
shmname = root_atom_contents("I3_SHMLOG_PATH", NULL, 0);
if (shmname == NULL && !is_debug_build()) {
fprintf(stderr, "You seem to be using a release version of i3:\n %s\n\n", I3_VERSION);
fprintf(stderr, "Release versions do not use SHM logging by default,\ntherefore i3-dump-log does not work.\n\n");
fprintf(stderr, "Please follow this guide instead:\nhttps://i3wm.org/docs/debugging-release-version.html\n");
exit(1);
}
}
if (shmname == NULL) {
errx(EXIT_FAILURE, "Cannot get I3_SHMLOG_PATH atom contents. Is i3 running on this display?");
}
}
if (*shmname == '\0')
errx(EXIT_FAILURE, "Cannot dump log: SHM logging is disabled in i3.");
struct stat statbuf;
/* NB: While we must never write, we need O_RDWR for the pthread condvar. */
int logbuffer_shm = shm_open(shmname, O_RDWR, 0);
if (logbuffer_shm == -1) {
err(EXIT_FAILURE, "Could not shm_open SHM segment for the i3 log (%s)", shmname);
}
if (fstat(logbuffer_shm, &statbuf) != 0) {
err(EXIT_FAILURE, "stat(%s)", shmname);
}
logbuffer = mmap(NULL, statbuf.st_size, PROT_READ, MAP_SHARED, logbuffer_shm, 0);
if (logbuffer == MAP_FAILED) {
err(EXIT_FAILURE, "Could not mmap SHM segment for the i3 log");
}
header = (i3_shmlog_header *)logbuffer;
if (verbose) {
printf("next_write = %d, last_wrap = %d, logbuffer_size = %d, shmname = %s\n",
header->offset_next_write, header->offset_last_wrap, header->size, shmname);
}
free(shmname);
walk = logbuffer + header->offset_next_write;
/* We first need to print old content in case there was at least one
* wrapping already. */
if (*walk != '\0') {
/* In case there was a write to the buffer already, skip the first
* old line, it very likely is mangled. Not a problem, though, the log
* is chatty enough to have plenty lines left. */
while (*walk != '\n')
walk++;
walk++;
}
/* In case there was no wrapping, this is a no-op, otherwise it prints the
* old lines. */
wrap_count = 0;
check_for_wrap();
/* Then start from the beginning and print the newer lines */
walk = logbuffer + sizeof(i3_shmlog_header);
print_till_end();
#if !defined(__OpenBSD__)
if (!follow) {
return 0;
}
char *log_stream_socket_path = root_atom_contents("I3_LOG_STREAM_SOCKET_PATH", NULL, 0);
if (log_stream_socket_path == NULL) {
errx(EXIT_FAILURE, "could not determine i3 log stream socket path: possible i3-dump-log and i3 version mismatch");
}
int sockfd = socket(AF_LOCAL, SOCK_STREAM, 0);
if (sockfd == -1) {
err(EXIT_FAILURE, "Could not create socket");
}
(void)fcntl(sockfd, F_SETFD, FD_CLOEXEC);
struct sockaddr_un addr;
memset(&addr, 0, sizeof(struct sockaddr_un));
addr.sun_family = AF_LOCAL;
strncpy(addr.sun_path, log_stream_socket_path, sizeof(addr.sun_path) - 1);
if (connect(sockfd, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un)) < 0) {
err(EXIT_FAILURE, "Could not connect to i3 on socket %s", log_stream_socket_path);
}
/* Same size as the buffer used in log.c vlog(): */
char buf[4096];
for (;;) {
const int n = read(sockfd, buf, sizeof(buf));
if (n == -1) {
err(EXIT_FAILURE, "read(log-stream-socket):");
}
if (n == 0) {
exit(0); /* i3 closed the socket */
}
buf[n] = '\0';
swrite(STDOUT_FILENO, buf, n);
}
#endif
exit(0);
return 0;
}