b1e2f48da54d57662fab5b8a18a2190044e77790
[paraslash.git] / dccp_send.c
1 /*
2 * Copyright (C) 2006-2008 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file dccp_send.c paraslash's dccp sender */
8
9 /*
10 * based on server.c of dccp-cs-0.01.tar.bz2,
11 * (C) 2005 Ian McDonald <imcdnzl@gmail.com>
12 */
13
14 #include <sys/types.h>
15 #include <dirent.h>
16
17 #include "para.h"
18 #include "error.h"
19 #include "string.h"
20 #include "afh.h"
21 #include "afs.h"
22 #include "server.h"
23 #include "net.h"
24 #include "list.h"
25 #include "vss.h"
26 #include "send.h"
27 #include "fd.h"
28 #include "close_on_fork.h"
29 #include "chunk_queue.h"
30 #include "server.cmdline.h"
31
32 /** the list of connected clients **/
33 static struct list_head clients;
34 static int listen_fd = -1;
35 static struct sender *self;
36
37 /** Maximal number of bytes in a chunk queue. */
38 #define DCCP_MAX_PENDING_BYTES 40000
39
40 /** describes one connected client */
41 struct dccp_client {
42 /** the dccp socket */
43 int fd;
44 /** The socket `name' of the client. */
45 char *name;
46 /** the position of this client in the client list */
47 struct list_head node;
48 /** non-zero if audio file header has been sent */
49 int header_sent;
50 /** The list of pending chunks for this client. */
51 struct chunk_queue *cq;
52 };
53
54 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
55 __a_unused fd_set *wfds)
56 {
57 if (listen_fd < 0)
58 return;
59 FD_SET(listen_fd, rfds);
60 *max_fileno = PARA_MAX(*max_fileno, listen_fd);
61 }
62
63 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
64 {
65 struct dccp_client *dc;
66 int ret, fd;
67
68 if (listen_fd < 0 || !FD_ISSET(listen_fd, rfds))
69 return;
70 ret = para_accept(listen_fd, NULL, 0);
71 if (ret < 0) {
72 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
73 return;
74 }
75 fd = ret;
76 /*
77 * Bypass unused CCID paths: the sender does not receive application data
78 * from the client; by shutting down this unused communication path we can
79 * reduce processing costs a bit. See analogous comment in dccp_recv.c.
80 */
81 if (shutdown(fd, SHUT_RD) < 0) {
82 PARA_ERROR_LOG("shutdown(SHUT_RD): %s\n", strerror(errno));
83 goto err;
84 }
85 ret = mark_fd_nonblocking(fd);
86 if (ret < 0) {
87 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
88 goto err;
89 }
90 dc = para_calloc(sizeof(struct dccp_client));
91 dc->fd = fd;
92 dc->name = make_message("%s", remote_name(dc->fd));
93 PARA_NOTICE_LOG("connection from %s\n", dc->name);
94 para_list_add(&dc->node, &clients);
95 add_close_on_fork_list(dc->fd);
96 dc->cq = cq_new(DCCP_MAX_PENDING_BYTES);
97 return;
98 err:
99 close(fd);
100 }
101
102 static int dccp_open(void)
103 {
104 int ret = para_listen(AF_UNSPEC, IPPROTO_DCCP, conf.dccp_port_arg);
105
106 if (ret < 0)
107 return ret;
108 listen_fd = ret;
109 ret = mark_fd_nonblocking(listen_fd);
110 if (ret < 0) {
111 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
112 exit(EXIT_FAILURE);
113 }
114 add_close_on_fork_list(listen_fd);
115 return 1;
116 }
117
118 static void dccp_shutdown_client(struct dccp_client *dc)
119 {
120 PARA_DEBUG_LOG("shutting down %s (fd %d)\n", dc->name, dc->fd);
121 free(dc->name);
122 close(dc->fd);
123 del_close_on_fork_list(dc->fd);
124 cq_destroy(dc->cq);
125 list_del(&dc->node);
126 free(dc);
127 }
128
129 /*
130 * ret: Negative on errors, zero if nothing was written and write returned
131 * EAGAIN, number of bytes written else.
132 */
133 static int dccp_write(int fd, const char *buf, size_t len)
134 {
135 size_t written = 0;
136 int ret = 0;
137
138 while (written < len) {
139 ret = write(fd, buf + written, PARA_MIN(1024, len - written));
140 /*
141 * Error handling: CCID3 has a sending wait queue which fills
142 * up and is emptied asynchronously. The EAGAIN case means that
143 * there is currently no space in the wait queue, but this can
144 * change at any moment and is thus not an error condition.
145 */
146 if (ret < 0 && errno == EAGAIN)
147 return written;
148 if (ret < 0)
149 return -ERRNO_TO_PARA_ERROR(errno);
150 written += ret;
151 }
152 return written;
153 }
154
155 static int queue_chunk_or_shutdown(struct dccp_client *dc, long unsigned chunk_num,
156 size_t sent)
157 {
158 int ret = cq_enqueue(dc->cq, chunk_num, sent);
159 if (ret < 0) {
160 PARA_NOTICE_LOG("enqueue error\n");
161 dccp_shutdown_client(dc);
162 }
163 return ret;
164 }
165
166 static int send_queued_chunks(struct dccp_client *dc)
167 {
168 struct queued_chunk *qc;
169 while ((qc = cq_peek(dc->cq))) {
170 char *buf;
171 size_t len;
172 int ret;
173 cq_get(qc, &buf, &len);
174 ret = dccp_write(dc->fd, buf, len);
175 if (ret < 0)
176 return ret;
177 cq_update(dc->cq, ret);
178 if (ret != len)
179 return 1;
180 cq_dequeue(dc->cq);
181 }
182 return 1;
183 }
184
185 static void dccp_send(long unsigned current_chunk,
186 __a_unused long unsigned chunks_sent, const char *buf, size_t len)
187 {
188 struct dccp_client *dc, *tmp;
189 int ret;
190 char *header_buf;
191
192 if (listen_fd < 0 || !len)
193 return;
194
195 list_for_each_entry_safe(dc, tmp, &clients, node) {
196 if (!dc->header_sent && current_chunk) {
197 size_t header_len;
198 header_buf = vss_get_header(&header_len);
199 if (header_buf && header_len > 0) {
200 if (queue_chunk_or_shutdown(dc, -1U, 0) < 0)
201 continue;
202 }
203 dc->header_sent = 1;
204 }
205 ret = send_queued_chunks(dc);
206 if (ret < 0) {
207 dccp_shutdown_client(dc);
208 continue;
209 }
210 // PARA_DEBUG_LOG("writing %d bytes to fd %d\n", len, dc->fd);
211 ret = dccp_write(dc->fd, buf, len);
212 if (ret < 0) {
213 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
214 dccp_shutdown_client(dc);
215 continue;
216 }
217 if (ret != len)
218 queue_chunk_or_shutdown(dc, current_chunk, ret);
219 }
220 }
221
222 static void dccp_shutdown_clients(void)
223 {
224 struct dccp_client *dc, *tmp;
225
226 list_for_each_entry_safe(dc, tmp, &clients, node)
227 dccp_shutdown_client(dc);
228 }
229
230 static char *dccp_info(void)
231 {
232 static char *buf;
233 int num_clients = 0;
234 struct dccp_client *dc, *tmp;
235
236 free(buf);
237 list_for_each_entry_safe(dc, tmp, &clients, node)
238 num_clients++;
239 buf = make_message("dccp connected clients: %d\n", num_clients);
240 return buf;
241 }
242
243 static char *dccp_help(void)
244 {
245 return make_message("no help available\n");
246 }
247
248 /**
249 * the init function of the dccp sender
250 *
251 * \param s pointer to the dccp sender struct
252 *
253 * It initializes all function pointers of \a s and starts
254 * listening on the given port.
255 */
256 void dccp_send_init(struct sender *s)
257 {
258 int ret;
259
260 INIT_LIST_HEAD(&clients);
261 s->info = dccp_info;
262 s->send = dccp_send;
263 s->pre_select = dccp_pre_select;
264 s->post_select = dccp_post_select;
265 s->shutdown_clients = dccp_shutdown_clients;
266 s->help = dccp_help;
267 s->client_cmds[SENDER_ON] = NULL;
268 s->client_cmds[SENDER_OFF] = NULL;
269 s->client_cmds[SENDER_DENY] = NULL;
270 s->client_cmds[SENDER_ALLOW] = NULL;
271 s->client_cmds[SENDER_ADD] = NULL;
272 s->client_cmds[SENDER_DELETE] = NULL;
273 self = s;
274 ret = dccp_open();
275 if (ret < 0)
276 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
277 }