sway/swaybar/status_line.c
Simon Ser 414950bbc8 swaybar: fix errno handling in status_handle_readable
If getline fails once, it was not reset before the next getline
call. errno is only overwritten by getline on error.
2021-12-21 12:12:54 +01:00

207 lines
6 KiB
C

#define _POSIX_C_SOURCE 200809L
#include <assert.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <json.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "log.h"
#include "loop.h"
#include "swaybar/bar.h"
#include "swaybar/config.h"
#include "swaybar/i3bar.h"
#include "swaybar/status_line.h"
static void status_line_close_fds(struct status_line *status) {
if (status->read_fd != -1) {
loop_remove_fd(status->bar->eventloop, status->read_fd);
close(status->read_fd);
status->read_fd = -1;
}
if (status->write_fd != -1) {
close(status->write_fd);
status->write_fd = -1;
}
}
void status_error(struct status_line *status, const char *text) {
status_line_close_fds(status);
status->protocol = PROTOCOL_ERROR;
status->text = text;
}
bool status_handle_readable(struct status_line *status) {
ssize_t read_bytes = 1;
switch (status->protocol) {
case PROTOCOL_UNDEF:
errno = 0;
int available_bytes;
if (ioctl(status->read_fd, FIONREAD, &available_bytes) == -1) {
sway_log(SWAY_ERROR, "Unable to read status command output size");
status_error(status, "[error reading from status command]");
return true;
}
if ((size_t)available_bytes + 1 > status->buffer_size) {
// need room for leading '\0' too
status->buffer_size = available_bytes + 1;
status->buffer = realloc(status->buffer, status->buffer_size);
}
if (status->buffer == NULL) {
sway_log_errno(SWAY_ERROR, "Unable to read status line");
status_error(status, "[error reading from status command]");
return true;
}
read_bytes = read(status->read_fd, status->buffer, available_bytes);
if (read_bytes != available_bytes) {
status_error(status, "[error reading from status command]");
return true;
}
status->buffer[available_bytes] = 0;
// the header must be sent completely the first time round
char *newline = strchr(status->buffer, '\n');
json_object *header, *version;
if (newline != NULL
&& (header = json_tokener_parse(status->buffer))
&& json_object_object_get_ex(header, "version", &version)
&& json_object_get_int(version) == 1) {
sway_log(SWAY_DEBUG, "Using i3bar protocol.");
status->protocol = PROTOCOL_I3BAR;
json_object *click_events;
if (json_object_object_get_ex(header, "click_events", &click_events)
&& json_object_get_boolean(click_events)) {
sway_log(SWAY_DEBUG, "Enabling click events.");
status->click_events = true;
if (write(status->write_fd, "[\n", 2) != 2) {
status_error(status, "[failed to write to status command]");
json_object_put(header);
return true;
}
}
json_object *float_event_coords;
if (json_object_object_get_ex(header, "float_event_coords", &float_event_coords)
&& json_object_get_boolean(float_event_coords)) {
sway_log(SWAY_DEBUG, "Enabling floating-point coordinates.");
status->float_event_coords = true;
}
json_object *signal;
if (json_object_object_get_ex(header, "stop_signal", &signal)) {
status->stop_signal = json_object_get_int(signal);
sway_log(SWAY_DEBUG, "Setting stop signal to %d", status->stop_signal);
}
if (json_object_object_get_ex(header, "cont_signal", &signal)) {
status->cont_signal = json_object_get_int(signal);
sway_log(SWAY_DEBUG, "Setting cont signal to %d", status->cont_signal);
}
json_object_put(header);
wl_list_init(&status->blocks);
status->tokener = json_tokener_new();
status->buffer_index = strlen(newline + 1);
memmove(status->buffer, newline + 1, status->buffer_index + 1);
return i3bar_handle_readable(status);
}
sway_log(SWAY_DEBUG, "Using text protocol.");
status->protocol = PROTOCOL_TEXT;
status->text = status->buffer;
// intentional fall-through
case PROTOCOL_TEXT:
while (true) {
if (status->buffer[read_bytes - 1] == '\n') {
status->buffer[read_bytes - 1] = '\0';
}
errno = 0;
read_bytes = getline(&status->buffer,
&status->buffer_size, status->read);
if (errno == EAGAIN) {
clearerr(status->read);
return true;
} else if (errno) {
status_error(status, "[error reading from status command]");
return true;
}
}
case PROTOCOL_I3BAR:
return i3bar_handle_readable(status);
default:
return false;
}
}
struct status_line *status_line_init(char *cmd) {
struct status_line *status = calloc(1, sizeof(struct status_line));
status->stop_signal = SIGSTOP;
status->cont_signal = SIGCONT;
status->buffer_size = 8192;
status->buffer = malloc(status->buffer_size);
int pipe_read_fd[2];
int pipe_write_fd[2];
if (pipe(pipe_read_fd) != 0 || pipe(pipe_write_fd) != 0) {
sway_log(SWAY_ERROR, "Unable to create pipes for status_command fork");
exit(1);
}
assert(!getenv("WAYLAND_SOCKET") && "display must be initialized before "
" starting `status-command`; WAYLAND_SOCKET should not be set");
status->pid = fork();
if (status->pid < 0) {
sway_log_errno(SWAY_ERROR, "fork failed");
exit(1);
} else if (status->pid == 0) {
setpgid(0, 0);
dup2(pipe_read_fd[1], STDOUT_FILENO);
close(pipe_read_fd[0]);
close(pipe_read_fd[1]);
dup2(pipe_write_fd[0], STDIN_FILENO);
close(pipe_write_fd[0]);
close(pipe_write_fd[1]);
char *const _cmd[] = { "sh", "-c", cmd, NULL, };
execvp(_cmd[0], _cmd);
exit(1);
}
close(pipe_read_fd[1]);
status->read_fd = pipe_read_fd[0];
fcntl(status->read_fd, F_SETFL, O_NONBLOCK);
close(pipe_write_fd[0]);
status->write_fd = pipe_write_fd[1];
fcntl(status->write_fd, F_SETFL, O_NONBLOCK);
status->read = fdopen(status->read_fd, "r");
status->write = fdopen(status->write_fd, "w");
return status;
}
void status_line_free(struct status_line *status) {
status_line_close_fds(status);
kill(-status->pid, status->cont_signal);
kill(-status->pid, SIGTERM);
waitpid(status->pid, NULL, 0);
if (status->protocol == PROTOCOL_I3BAR) {
struct i3bar_block *block, *tmp;
wl_list_for_each_safe(block, tmp, &status->blocks, link) {
wl_list_remove(&block->link);
i3bar_block_unref(block);
}
json_tokener_free(status->tokener);
}
free(status->buffer);
free(status);
}