fix potential segfault in para_client
[paraslash.git] / dccp_send.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 /** \file dccp_send.c paraslash's dccp sender */
20
21 /*
22 * based on server.c of dccp-cs-0.01.tar.bz2,
23 * (C) 2005 Ian McDonald <imcdnzl@gmail.com>
24 */
25
26 #include "server.h"
27 #include "net.h"
28 #include "list.h"
29 #include "afs.h"
30 #include "send.h"
31 #include "dccp.h"
32 #include "error.h"
33 #include "string.h"
34 #include "server.cmdline.h"
35 extern struct gengetopt_args_info conf;
36 /** the list of connected clients **/
37 static struct list_head clients;
38 static int listen_fd = -1;
39 static struct sender *self;
40
41 /** describes one connected client */
42 struct dccp_client {
43 /** the dccp socket */
44 int fd;
45 /** address information about the client */
46 struct sockaddr_in addr;
47 /** the position of this client in the client list */
48 struct list_head node;
49 /** non-zero if audio file header has been sent */
50 int header_sent;
51 };
52
53 static void dccp_pre_select(__unused struct audio_format *af, int *max_fileno, fd_set *rfds,
54 __unused fd_set *wfds)
55 {
56 if (listen_fd < 0)
57 return;
58 FD_SET(listen_fd, rfds);
59 *max_fileno = MAX(*max_fileno, listen_fd);
60 }
61
62 static void dccp_post_select(__unused struct audio_format *af, fd_set *rfds,
63 __unused fd_set *wfds)
64 {
65 struct dccp_client *dc;
66 int ret;
67
68 if (!FD_ISSET(listen_fd, rfds))
69 return;
70 dc = para_calloc(sizeof(struct dccp_client));
71 ret = para_accept(listen_fd, &dc->addr, sizeof(struct sockaddr_in));
72 if (ret < 0) {
73 PARA_ERROR_LOG("%s", PARA_STRERROR(-ret));
74 return;
75 }
76 PARA_NOTICE_LOG("connection from %s\n", inet_ntoa(dc->addr.sin_addr));
77 dc->fd = ret;
78 list_add(&dc->node, &clients);
79 }
80
81 static int dccp_open(void)
82 {
83 struct sockaddr_in servaddr;
84 int ret;
85
86 ret = dccp_get_socket();
87 if (ret < 0)
88 return ret;
89 listen_fd = ret;
90
91 bzero(&servaddr, sizeof(servaddr));
92 servaddr.sin_family = AF_INET;
93 servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
94 servaddr.sin_port = htons(conf.dccp_port_arg);
95 ret = bind(listen_fd, (struct sockaddr *)&servaddr, sizeof(servaddr));
96 if (ret < 0)
97 return -E_DCCP_BIND;
98 ret = dccp_set_socket(listen_fd);
99 if (ret < 0)
100 return ret;
101 ret = listen(listen_fd, 0);
102 if (ret < 0)
103 return -E_DCCP_LISTEN;
104 PARA_DEBUG_LOG("listening on fd %d\n", listen_fd);
105 return 1;
106 }
107
108 static void dccp_shutdown_client(struct dccp_client *dc)
109 {
110 PARA_DEBUG_LOG("shutting down %s (fd %d)\n", inet_ntoa(dc->addr.sin_addr),
111 dc->fd);
112 close(dc->fd);
113 list_del(&dc->node);
114 free(dc);
115 }
116
117 static int dccp_write(int fd, const char *buf, size_t len)
118 {
119 size_t send, written = 0;
120 int ret;
121 again:
122 send = MIN(1024, len - written);
123 ret = write(fd, buf + written, send);
124 if (ret < 0)
125 goto err_out;
126 written += ret;
127 if (written >= len)
128 return written;
129 ret = write_ok(fd);
130 if (ret > 0)
131 goto again;
132 err_out:
133 return -E_DCCP_WRITE;
134 }
135
136 static void dccp_send(__unused struct audio_format *af,
137 long unsigned current_chunk,
138 __unused long unsigned chunks_sent, const char *buf, size_t len)
139 {
140 struct dccp_client *dc, *tmp;
141 int ret, header_len;
142 char *header_buf;
143
144 if (listen_fd < 0 || !len)
145 return;
146
147 list_for_each_entry_safe(dc, tmp, &clients, node) {
148 ret = write_ok(dc->fd);
149 if (ret < 0) {
150 dccp_shutdown_client(dc);
151 continue;
152 }
153 if (!ret)
154 continue;
155 if (!dc->header_sent && af->get_header_info && current_chunk) {
156 header_buf = af->get_header_info(&header_len);
157 if (!header_buf || header_len <= 0)
158 continue; /* header not yet available */
159 ret = dccp_write(dc->fd, header_buf, header_len);
160 if (ret != header_len) {
161 int err = errno;
162 PARA_ERROR_LOG("header write: %d/%d (%s)\n",
163 ret, header_len, ret < 0?
164 strerror(err) : "");
165 dccp_shutdown_client(dc);
166 continue;
167 }
168 dc->header_sent = 1;
169 ret = write_ok(dc->fd);
170 if (ret < 0) {
171 dccp_shutdown_client(dc);
172 continue;
173 }
174 if (!ret)
175 continue;
176 }
177 // PARA_DEBUG_LOG("writing %d bytes to fd %d\n", len, dc->fd);
178 ret = dccp_write(dc->fd, buf, len);
179 if (ret != len)
180 dccp_shutdown_client(dc);
181 }
182 }
183
184 static void dccp_shutdown_clients(void)
185 {
186 struct dccp_client *dc, *tmp;
187
188 list_for_each_entry_safe(dc, tmp, &clients, node)
189 dccp_shutdown_client(dc);
190 }
191
192 static char *dccp_info(void)
193 {
194 static char *buf;
195 int num_clients = 0;
196 struct dccp_client *dc, *tmp;
197
198 free(buf);
199 list_for_each_entry_safe(dc, tmp, &clients, node)
200 num_clients++;
201 buf = make_message("dccp connected clients: %d\n", num_clients);
202 return buf;
203 }
204
205 static char *dccp_help(void)
206 {
207 return make_message("no help available\n");
208 }
209
210 /**
211 * the init function of the dccp sender
212 *
213 * \param s pointer to the dccp sender struct
214 *
215 * It initializes all function pointers of \a s and starts
216 * listening on the given port.
217 */
218 void dccp_send_init(struct sender *s)
219 {
220 int ret;
221
222 INIT_LIST_HEAD(&clients);
223 s->info = dccp_info;
224 s->send = dccp_send;
225 s->pre_select = dccp_pre_select;
226 s->post_select = dccp_post_select;
227 s->shutdown_clients = dccp_shutdown_clients;
228 s->help = dccp_help;
229 s->client_cmds[SENDER_ON] = NULL;
230 s->client_cmds[SENDER_OFF] = NULL;
231 s->client_cmds[SENDER_DENY] = NULL;
232 s->client_cmds[SENDER_ALLOW] = NULL;
233 s->client_cmds[SENDER_ADD] = NULL;
234 s->client_cmds[SENDER_DELETE] = NULL;
235 self = s;
236 ret = dccp_open();
237 if (ret < 0)
238 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
239 else
240 s->status = SENDER_ON;
241 }