fix two bugs concerning blocking fds
[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 "grab_client.cmdline.h"
28 #include "list.h"
29 #include "sched.h"
30 #include "filter.h"
31 #include "grab_client.h"
32 #include "audiod.h"
33 #include "error.h"
34 #include "string.h"
35 #include "fd.h"
36
37 /** grab clients that are not yet attached to a filter node */
38 struct list_head inactive_grab_client_list;
39
40 static int max_num_filters(void)
41 {
42 int i, ret = 0;
43 for (i = 0; audio_formats[i]; i++) {
44 PARA_INFO_LOG("%s filter chain length: %d\n", audio_formats[i],
45 num_filters(i));
46 ret = PARA_MAX(ret, num_filters(i));
47 }
48 PARA_INFO_LOG("maximal filter chain length: %d\n", ret);
49 return ret;
50 }
51
52 static int gc_write(char *buf, size_t len, struct filter_callback *fcb)
53 {
54 struct grab_client *gc = fcb->data;
55 struct timeval tv = {0, 100};
56 int ret;
57
58 // PARA_INFO_LOG("writing %d bytes to fd %d\n", len, gc->fd);
59 fd_set wfds;
60 FD_ZERO(&wfds);
61 FD_SET(gc->fd, &wfds);
62 ret = para_select(gc->fd + 1, NULL, &wfds, &tv);
63 if (ret <= 0) {
64 if (gc->mode == GRAB_PEDANTIC)
65 return -E_PEDANTIC_GRAB;
66 if (gc->mode == GRAB_SLOPPY)
67 return 1;
68 }
69 rewrite:
70 ret = write(gc->fd, buf, len);
71 if (ret < 0) {
72 ret = -E_GC_WRITE;
73 gc->error = E_GC_WRITE;
74 } else {
75 if (ret != len) {
76 if (gc->mode == GRAB_PEDANTIC)
77 return -E_PEDANTIC_GRAB;
78 if (gc->mode == GRAB_AGGRESSIVE) {
79 len -= ret;
80 memmove(buf, buf + ret, len);
81 goto rewrite;
82 }
83 }
84 }
85 return ret;
86 }
87
88 /* TODO: gengetopt can handle the grab client modes */
89 static int check_gc_args(struct grab_client *gc)
90 {
91 int i;
92 struct grab_client_args_info *c = gc->conf;
93 char **mv = grab_client_cmdline_parser_mode_values;
94
95 PARA_INFO_LOG("filter_num: %d\n", c->filter_num_arg);
96 for (i = 0; mv[i]; i++)
97 if (!strcmp(c->mode_arg, mv[i]))
98 break;
99 if (!mv[i])
100 return -E_GC_SYNTAX;
101 gc->mode = i;
102 gc->audio_format_num = -1;
103 if (c->audio_format_given) {
104 gc->audio_format_num = get_audio_format_num(c->audio_format_arg);
105 if (gc->audio_format_num < 0)
106 return gc->audio_format_num;
107 }
108 if (c->slot_arg > MAX_STREAM_SLOTS)
109 return -E_BAD_GC_SLOT;
110 if (c->filter_num_arg <= 0)
111 return -E_BAD_GC_FILTER_NUM;
112 if (c->audio_format_given) {
113 if (num_filters(gc->audio_format_num) < c->filter_num_arg)
114 return -E_BAD_GC_FILTER_NUM;
115 } else
116 if (c->filter_num_arg > max_num_filters())
117 return -E_BAD_GC_FILTER_NUM;
118
119 return 1;
120 }
121
122 static void add_inactive_gc(struct grab_client *gc)
123 {
124 PARA_INFO_LOG("adding grab client %p (fd %d) to inactive list\n",
125 gc, gc->fd);
126 list_add(&gc->node, &inactive_grab_client_list);
127 }
128
129 static void gc_free(struct grab_client *gc)
130 {
131 int i;
132
133 for (i = 0; i < gc->argc; i++)
134 free(gc->argv[i]);
135 free(gc->argv);
136 free(gc->conf);
137 free(gc);
138
139 }
140
141 static void gc_close(struct filter_callback *fcb)
142 {
143 struct grab_client *gc = fcb->data;
144
145 if (gc->conf->one_shot_given || gc->error) {
146 PARA_INFO_LOG("closing fd %d (grab client %p)\n", gc->fd, gc);
147 close(gc->fd);
148 gc_free(gc);
149 /* close on fork ?*/
150 return;
151 }
152 add_inactive_gc(gc);
153 }
154
155 /**
156 * move a grab client from the inactive list to a filter node
157 *
158 * \param gc the grab client to activate
159 * \param fn the filter node \a gc gets attached to
160 *
161 * \sa filter_node::callbacks, inactive_grab_client_list
162 */
163 void activate_grab_client(struct grab_client *gc, struct filter_node *fn)
164 {
165 PARA_INFO_LOG("activating %p (fd %d, filter node: %p)\n", gc, gc->fd, fn);
166 list_del(&gc->node);
167 list_add(&gc->fcb.node, &fn->callbacks);
168 }
169
170 /**
171 * activate inactive grab clients if possible
172 *
173 * \param slot_num audiod's slot for the new audio file
174 * \param audio_format_num the number of the audio format of the new audio file
175 * \param filter_list the list of activated filters for that new audio file
176 *
177 * This is called from audiod.c when the current audio file changes. It loops
178 * over all inactive grab clients and checks each grab client's configuration
179 * to determine if the client in question wishes to grab the new stream. If
180 * yes, this grab client is moved from the inactive grab client list to an
181 * appropriate filter_node.
182 *
183 * \sa filter_chain_info::filters, inactive_grab_client_list,
184 * activate_grab_client
185 */
186 void activate_inactive_grab_clients(int slot_num, int audio_format_num,
187 struct list_head *filter_list)
188 {
189 struct grab_client *gc, *tmp;
190 int i;
191 struct filter_node *fn;
192
193 list_for_each_entry_safe(gc, tmp, &inactive_grab_client_list, node) {
194 // PARA_INFO_LOG("checking inactive grab client %p\n", gc);
195 if (gc->conf->slot_arg >= 0 && gc->conf->slot_arg != slot_num)
196 continue;
197 if (gc->audio_format_num >= 0 && gc->audio_format_num !=
198 audio_format_num)
199 continue;
200 if (gc->conf->filter_num_arg >= 0 &&
201 num_filters(gc->audio_format_num)
202 < gc->conf->filter_num_arg)
203 continue;
204 i = 1;
205 list_for_each_entry(fn, filter_list, node) {
206 if (gc->conf->filter_num_arg <= 0
207 || i == gc->conf->filter_num_arg)
208 break;
209 i++;
210 }
211 activate_grab_client(gc, fn);
212 }
213 }
214
215 /**
216 * check the command line options and allocate a grab_client structure
217 *
218 * \param fd the file descriptor of the client
219 * \param line the command line
220 * \param err non-zero if an error occured
221 *
222 * If the command line options given by \a argc and \a argv are valid.
223 * allocate a struct grab_client and initialize it with this valid
224 * configuration. Moreover, add the new grab client to the inactive list.
225 *
226 * \return On success, this function returns a pointer to the newly created
227 * struct. On errors, it returns NULL and sets \a err appropriately.
228 *
229 * \sa grab_client, inactive_grab_client_list, activate_grab_client,
230 * filter_node::callbacks
231 */
232 /*
233 * argc, argv get freed when com_grab() returns, so we have to make a
234 * copy.
235 */
236 struct grab_client *grab_client_new(int fd, char *line, int *err)
237 {
238 int ret;
239 struct grab_client *gc = para_calloc(sizeof(struct grab_client));
240
241 gc->conf = para_calloc(sizeof(struct grab_client_args_info));
242
243 ret = grab_client_cmdline_parser_string(line, gc->conf, "grab");
244 *err = -E_GC_SYNTAX;
245 if (ret)
246 goto err_out;
247 *err = -E_GC_HELP_GIVEN;
248 if (gc->conf->help_given)
249 goto err_out;
250 *err = -E_GC_VERSION_GIVEN;
251 if (gc->conf->version_given)
252 goto err_out;
253 *err = check_gc_args(gc);
254 if (*err < 0)
255 goto err_out;
256 if (gc->conf->input_grab_given) {
257 gc->fcb.input_cb = gc_write;
258 gc->fcb.output_cb = NULL;
259 } else {
260 gc->fcb.output_cb = gc_write;
261 gc->fcb.input_cb = NULL;
262 }
263 gc->fd = fd;
264 gc->fcb.close = gc_close;
265 gc->fcb.data = gc;
266 add_inactive_gc(gc);
267 return gc;
268 err_out:
269 free(gc->conf);
270 free(gc);
271 return NULL;
272 }
273
274 /** initialize the grabbing subsystem.
275 *
276 * This has to be called once during startup before any other function from
277 * grab_client.c may be used. It initializes \a inactive_grab_client_list.
278 */
279 void init_grabbing()
280 {
281 PARA_INFO_LOG("%s", "grab init\n");
282 INIT_LIST_HEAD(&inactive_grab_client_list);
283 }
284