fix potential segfault in para_client
[paraslash.git] / grab_client.c
1 /*
2 * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18
19 /**
20 * \file grab_client.c functions for grabbing the stream at any position
21 * in a filter chain
22 *
23 * \sa filter_chain filter_chain_info filter
24 */
25
26 #include "para.h"
27 #include "close_on_fork.h"
28 #include "grab_client.cmdline.h"
29 #include "list.h"
30 #include "filter.h"
31 #include "grab_client.h"
32 #include "audiod.h"
33 #include "error.h"
34 #include "string.h"
35
36 /** grab clients that are not yet attached to a filter node */
37 struct list_head inactive_grab_client_list;
38
39 static int max_num_filters(void)
40 {
41 int i, ret = 0;
42 for (i = 0; audio_formats[i]; i++) {
43 PARA_INFO_LOG("%s filter chain length: %d\n", audio_formats[i],
44 num_filters(i));
45 ret = MAX(ret, num_filters(i));
46 }
47 PARA_INFO_LOG("maximal filter chain length: %d\n", ret);
48 return ret;
49 }
50
51 static int gc_write(char *buf, size_t len, struct filter_callback *fcb)
52 {
53 struct grab_client *gc = fcb->data;
54 struct timeval tv = {0, 100};
55 int ret;
56
57 // PARA_INFO_LOG("writing %d bytes to fd %d\n", len, gc->fd);
58 fd_set wfds;
59 do {
60 FD_ZERO(&wfds);
61 FD_SET(gc->fd, &wfds);
62 ret = select(gc->fd + 1, NULL, &wfds, NULL, &tv);
63 } while (ret == EAGAIN || ret == EINTR);
64 if (ret != 1) {
65 if (gc->mode == GRAB_PEDANTIC)
66 return -E_PEDANTIC_GRAB;
67 if (gc->mode == GRAB_SLOPPY)
68 return 1;
69 }
70 rewrite:
71 ret = write(gc->fd, buf, len);
72 if (ret < 0) {
73 ret = -E_GC_WRITE;
74 gc->error = E_GC_WRITE;
75 } else {
76 if (ret != len) {
77 if (gc->mode == GRAB_PEDANTIC)
78 return -E_PEDANTIC_GRAB;
79 if (gc->mode == GRAB_AGGRESSIVE) {
80 len -= ret;
81 memmove(buf, buf + ret, len);
82 goto rewrite;
83 }
84 }
85 }
86 return ret;
87 }
88
89 static int check_gc_args(struct grab_client *gc)
90 {
91 int i;
92 struct grab_client_args_info *conf = gc->conf;
93 char **mv = grab_client_cmdline_parser_mode_values;
94
95 PARA_INFO_LOG("filter_num: %d\n", gc->conf->filter_num_arg);
96 for (i = 0; mv[i]; i++)
97 if (!strcmp(conf->mode_arg, mv[i]))
98 break;
99 gc->mode = i;
100 if (conf->audio_format_given) {
101 gc->audio_format_num = get_audio_format_num(conf->audio_format_arg);
102 if (gc->audio_format_num < 0)
103 return gc->audio_format_num;
104 }
105 if (conf->slot_arg > MAX_STREAM_SLOTS)
106 return -E_BAD_GC_SLOT;
107 if (conf->filter_num_arg <= 0)
108 return -E_BAD_GC_FILTER_NUM;
109 if (conf->audio_format_given) {
110 if (num_filters(gc->audio_format_num) < conf->filter_num_arg)
111 return -E_BAD_GC_FILTER_NUM;
112 } else
113 if (conf->filter_num_arg > max_num_filters())
114 return -E_BAD_GC_FILTER_NUM;
115
116 return 1;
117 }
118
119 static void add_inactive_gc(struct grab_client *gc)
120 {
121 PARA_INFO_LOG("adding grab client %p (fd %d) to inactive list\n",
122 gc, gc->fd);
123 list_add(&gc->node, &inactive_grab_client_list);
124 }
125
126 static void gc_free(struct grab_client *gc)
127 {
128 int i;
129
130 for (i = 0; i < gc->argc; i++)
131 free(gc->argv[i]);
132 free(gc->argv);
133 free(gc->conf);
134 free(gc);
135
136 }
137
138 static void gc_close(struct filter_callback *fcb)
139 {
140 struct grab_client *gc = fcb->data;
141
142 if (gc->conf->one_shot_given || gc->error) {
143 PARA_INFO_LOG("closing fd %d (grab client %p)\n", gc->fd, gc);
144 del_close_on_fork_list(gc->fd);
145 close(gc->fd);
146 gc_free(gc);
147 /* close on fork ?*/
148 return;
149 }
150 add_inactive_gc(gc);
151 }
152
153 /**
154 * move a grab client from the inactive list to a filter node
155 *
156 * \param gc the grab client to activate
157 * \param fn the filter node \a gc gets attached to
158 *
159 * \sa filter_node::callbacks, inactive_grab_client_list
160 */
161 void activate_grab_client(struct grab_client *gc, struct filter_node *fn)
162 {
163 PARA_INFO_LOG("activating %p (fd %d, filter node: %p)\n", gc, gc->fd, fn);
164 list_del(&gc->node);
165 list_add(&gc->fcb.node, &fn->callbacks);
166 }
167
168 /**
169 * activate inactive grab clients if possible
170 *
171 * \param slot audiod's slot for the new audio file
172 * \param audio_format_num the number of the audio format of the new audio file
173 * \param filter_list the list of activated filters for that new audio file
174 *
175 * This is called from audiod.c when the current audio file changes. It loops
176 * over all inactive grab clients and checks each grab client's configuration
177 * to determine if the client in question wishes to grab the new stream. If
178 * yes, this grab client is moved from the inactive grab client list to an
179 * appropriate filter_node.
180 *
181 * \sa filter_chain_info::filters, inactive_grab_client_list,
182 * activate_grab_client
183 */
184 void activate_inactive_grab_clients(int slot, int audio_format_num,
185 struct list_head *filter_list)
186 {
187 struct grab_client *gc, *tmp;
188 int i;
189 struct filter_node *fn;
190
191 list_for_each_entry_safe(gc, tmp, &inactive_grab_client_list, node) {
192 // PARA_INFO_LOG("checking inactive grab client %p\n", gc);
193 if (gc->conf->slot_arg >= 0 && gc->conf->slot_arg != slot)
194 continue;
195 if (gc->audio_format_num >= 0 && gc->audio_format_num !=
196 audio_format_num)
197 continue;
198 if (gc->conf->filter_num_arg >= 0 &&
199 num_filters(gc->audio_format_num)
200 < gc->conf->filter_num_arg)
201 continue;
202 i = 1;
203 list_for_each_entry(fn, filter_list, node) {
204 if (gc->conf->filter_num_arg <= 0
205 || i == gc->conf->filter_num_arg)
206 break;
207 i++;
208 }
209 activate_grab_client(gc, fn);
210 }
211 }
212
213 /**
214 * check the command line options and allocate a grab_client structure
215 *
216 * \param fd the file descriptor of the client
217 * \param argc the number of command line options
218 * \param argv pointers to the command line options
219 * \param err non-zero if an error occured
220 *
221 * If the command line options given by \a argc and \a argv are valid.
222 * allocate a struct grab_client and initialize it with this valid
223 * configuration. Moreover, add the new grab client to the inactive list.
224 *
225 * \return On success, this function returns a pointer to the newly created
226 * struct. On errors, it returns NULL and sets \a err appropriately.
227 *
228 * \sa grab_client, inactive_grab_client_list, activate_grab_client,
229 * filter_node::callbacks
230 */
231 /*
232 * argc, argv get freed when com_grab() returns, so we have to make a
233 * copy.
234 */
235 __malloc struct grab_client *grab_client_new(int fd, int argc, char **argv, int *err)
236 {
237 int i, ret;
238 struct grab_client *gc = para_calloc(sizeof(struct grab_client));
239
240 gc->conf = para_calloc(sizeof(struct grab_client_args_info));
241 gc->argc = argc;
242 gc->argv = para_calloc((argc + 1) * sizeof(char *));
243
244 for (i = 0; i < argc; i++) {
245 gc->argv[i] = para_strdup(argv[i]);
246 PARA_INFO_LOG("argc: %d, argv[%d]: %s\n", argc, i, gc->argv[i]);
247 }
248 PARA_INFO_LOG("argv[%d]: %s\n", argc, gc->argv[argc]);
249 ret = grab_client_cmdline_parser(gc->argc, gc->argv , gc->conf);
250 *err = -E_GC_SYNTAX;
251 if (ret)
252 goto err_out;
253 *err = -E_GC_HELP_GIVEN;
254 if (gc->conf->help_given)
255 goto err_out;
256 *err = -E_GC_VERSION_GIVEN;
257 if (gc->conf->version_given)
258 goto err_out;
259 *err = check_gc_args(gc);
260 if (*err < 0)
261 goto err_out;
262 if (gc->conf->input_grab_given) {
263 gc->fcb.input_cb = gc_write;
264 gc->fcb.output_cb = NULL;
265 } else {
266 gc->fcb.output_cb = gc_write;
267 gc->fcb.input_cb = NULL;
268 }
269 gc->fd = fd;
270 gc->fcb.close = gc_close;
271 gc->fcb.data = gc;
272 add_inactive_gc(gc);
273 return gc;
274 err_out:
275 for (i = 0; i < argc; i++)
276 free(gc->argv[i]);
277 free(gc->argv);
278 free(gc->conf);
279 free(gc);
280 return NULL;
281 }
282
283 /** initialize the grabbing subsystem.
284 *
285 * This has to be called once during startup before any other function from
286 * grab_client.c may be used. It initializes \a inactive_grab_client_list.
287 */
288 void init_grabbing()
289 {
290 PARA_INFO_LOG("%s", "grab init\n");
291 INIT_LIST_HEAD(&inactive_grab_client_list);
292 }
293