8210c6be79
We now wait for the child process to send the first line before stopping it to use the signal which might be specified in the i3bar protocol header Since clients might use the same signal for both stop and cont, we also save the stopped state of the child to avoid stopping it while hidden!
134 lines
3.5 KiB
C
134 lines
3.5 KiB
C
/*
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* vim:ts=4:sw=4:expandtab
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*
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* i3bar - an xcb-based status- and ws-bar for i3
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* © 2010-2012 Axel Wagner and contributors (see also: LICENSE)
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*
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* parse_json_header.c: Parse the JSON protocol header to determine
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* protocol version and features.
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*
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*/
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <signal.h>
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#include <stdio.h>
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#include <fcntl.h>
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#include <string.h>
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#include <errno.h>
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#include <err.h>
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#include <ev.h>
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#include <stdbool.h>
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#include <stdint.h>
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#include <yajl/yajl_common.h>
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#include <yajl/yajl_parse.h>
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#include <yajl/yajl_version.h>
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#include "common.h"
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static enum {
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KEY_VERSION,
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KEY_STOP_SIGNAL,
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KEY_CONT_SIGNAL,
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NO_KEY
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} current_key;
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#if YAJL_MAJOR >= 2
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static int header_integer(void *ctx, long long val) {
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#else
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static int header_integer(void *ctx, long val) {
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#endif
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i3bar_child *child = ctx;
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switch (current_key) {
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case KEY_VERSION:
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child->version = val;
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break;
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case KEY_STOP_SIGNAL:
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child->stop_signal = val;
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break;
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case KEY_CONT_SIGNAL:
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child->cont_signal = val;
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break;
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default:
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break;
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}
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return 1;
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}
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#define CHECK_KEY(name) (stringlen == strlen(name) && \
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STARTS_WITH((const char*)stringval, stringlen, name))
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#if YAJL_MAJOR >= 2
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static int header_map_key(void *ctx, const unsigned char *stringval, size_t stringlen) {
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#else
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static int header_map_key(void *ctx, const unsigned char *stringval, unsigned int stringlen) {
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#endif
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if (CHECK_KEY("version")) {
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current_key = KEY_VERSION;
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} else if (CHECK_KEY("stop_signal")) {
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current_key = KEY_STOP_SIGNAL;
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} else if (CHECK_KEY("cont_signal")) {
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current_key = KEY_CONT_SIGNAL;
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}
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return 1;
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}
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static yajl_callbacks version_callbacks = {
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NULL, /* null */
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NULL, /* boolean */
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&header_integer,
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NULL, /* double */
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NULL, /* number */
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NULL, /* string */
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NULL, /* start_map */
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&header_map_key,
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NULL, /* end_map */
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NULL, /* start_array */
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NULL /* end_array */
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};
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static void child_init(i3bar_child *child) {
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child->version = 0;
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child->stop_signal = SIGSTOP;
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child->cont_signal = SIGCONT;
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}
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/*
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* Parse the JSON protocol header to determine protocol version and features.
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* In case the buffer does not contain a valid header (invalid JSON, or no
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* version field found), the 'correct' field of the returned header is set to
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* false. The amount of bytes consumed by parsing the header is returned in
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* *consumed (if non-NULL).
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*
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*/
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void parse_json_header(i3bar_child *child, const unsigned char *buffer, int length, unsigned int *consumed) {
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child_init(child);
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current_key = NO_KEY;
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#if YAJL_MAJOR >= 2
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yajl_handle handle = yajl_alloc(&version_callbacks, NULL, child);
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/* Allow trailing garbage. yajl 1 always behaves that way anyways, but for
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* yajl 2, we need to be explicit. */
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yajl_config(handle, yajl_allow_trailing_garbage, 1);
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#else
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yajl_parser_config parse_conf = { 0, 0 };
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yajl_handle handle = yajl_alloc(&version_callbacks, &parse_conf, NULL, child);
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#endif
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yajl_status state = yajl_parse(handle, buffer, length);
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if (state != yajl_status_ok) {
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child_init(child);
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if (consumed != NULL)
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*consumed = 0;
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} else {
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if (consumed != NULL)
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*consumed = yajl_get_bytes_consumed(handle);
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}
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yajl_free(handle);
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}
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