f0ba168957c4a76a7eac9b969c6d71c3f36a0fcf
[paraslash.git] / send_common.c
1 /*
2 * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file send_common.c Functions used by more than one paraslash sender. */
8
9 #include <dirent.h>
10 #include "para.h"
11 #include "error.h"
12 #include "string.h"
13 #include "fd.h"
14 #include "net.h"
15 #include "list.h"
16 #include "afh.h"
17 #include "afs.h"
18 #include "server.h"
19 #include "acl.h"
20 #include "send.h"
21 #include "close_on_fork.h"
22 #include "chunk_queue.h"
23 #include "vss.h"
24
25 /** Clients will be kicked if there are more than that many bytes pending. */
26 #define MAX_CQ_BYTES 40000
27
28 /**
29 * Open a passive socket of given layer4 type.
30 *
31 * Set the resultig file descriptor to nonblocking mode and add it to the list
32 * of fds that are being closed in the child process when the server calls
33 * fork().
34 *
35 * \param l4type The transport-layer protocol.
36 * \param port The port number.
37 *
38 * \return The listening fd on success, negative on errors.
39 */
40 static int open_sender(unsigned l4type, int port)
41 {
42 int fd, ret = para_listen(AF_UNSPEC, l4type, port);
43
44 if (ret < 0)
45 return ret;
46 fd = ret;
47 ret = mark_fd_nonblocking(fd);
48 if (ret < 0) {
49 close(fd);
50 return ret;
51 }
52 add_close_on_fork_list(fd);
53 return fd;
54 }
55
56 /**
57 * Shut down a connected client.
58 *
59 * \param sc The client to be shut down.
60 *
61 * Close the file descriptor given by \a sc, remove it from the close-on-fork
62 * list, destroy the chunk queue of this client, delete the client from the
63 * list of connected clients and free the sender_client struct.
64 */
65 void shutdown_client(struct sender_client *sc, struct sender_status *ss)
66 {
67 PARA_INFO_LOG("shutting down %s on fd %d\n", sc->name, sc->fd);
68 free(sc->name);
69 close(sc->fd);
70 del_close_on_fork_list(sc->fd);
71 cq_destroy(sc->cq);
72 list_del(&sc->node);
73 free(sc->private_data);
74 free(sc);
75 ss->num_clients--;
76 }
77
78 void shutdown_clients(struct sender_status *ss)
79 {
80 struct sender_client *sc, *tmp;
81 list_for_each_entry_safe(sc, tmp, &ss->client_list, node)
82 shutdown_client(sc, ss);
83 }
84
85 /**
86 * Write a buffer to a non-blocking file descriptor.
87 *
88 * \param fd The file descriptor.
89 * \param buf the buffer to write.
90 * \param len the number of bytes of \a buf.
91 * \param max_bytes_per_write Do not write more than that many bytes at once.
92 *
93 * If \a max_bytes_per_write is non-zero, do not send more than that many bytes
94 * per write().
95 *
96 * EAGAIN is not considered an error condition. For example CCID3 has a
97 * sending wait queue which fills up and is emptied asynchronously. The EAGAIN
98 * case means that there is currently no space in the wait queue, but this can
99 * change at any moment.
100 *
101 * \return Negative on errors, number of bytes written else.
102 */
103 static int write_nonblock(int fd, const char *buf, size_t len,
104 size_t max_bytes_per_write)
105 {
106 size_t written = 0;
107 int ret = 0;
108
109 while (written < len) {
110 size_t num = len - written;
111
112 if (max_bytes_per_write && max_bytes_per_write < num)
113 num = max_bytes_per_write;
114 ret = write(fd, buf + written, num);
115 if (ret < 0 && errno == EAGAIN)
116 return written;
117 if (ret < 0)
118 return -ERRNO_TO_PARA_ERROR(errno);
119 written += ret;
120 }
121 return written;
122 }
123
124 static int queue_chunk_or_shutdown(struct sender_client *sc,
125 struct sender_status *ss, long unsigned chunk_num,
126 size_t sent)
127 {
128 int ret = cq_enqueue(sc->cq, chunk_num, sent);
129 if (ret < 0)
130 shutdown_client(sc, ss);
131 return ret;
132 }
133
134 /* return: negative on errors, zero if not everything was sent, one otherwise */
135 static int send_queued_chunks(struct sender_client *sc,
136 size_t max_bytes_per_write)
137 {
138 struct queued_chunk *qc;
139 while ((qc = cq_peek(sc->cq))) {
140 char *buf;
141 size_t len;
142 int ret;
143 cq_get(qc, &buf, &len);
144 ret = write_nonblock(sc->fd, buf, len, max_bytes_per_write);
145 if (ret < 0)
146 return ret;
147 cq_update(sc->cq, ret);
148 if (ret != len)
149 return 0;
150 cq_dequeue(sc->cq);
151 }
152 return 1;
153 }
154
155 /**
156 * Send one chunk of audio data to a connected client.
157 *
158 * \param sc The client.
159 * \param max_bytes_per_write Split writes to chunks of at most that many bytes.
160 * \param current_chunk The number of the chunk to write.
161 * \param buf The data to write.
162 * \param len The number of bytes of \a buf.
163 *
164 * On errors, the client is shut down. If only a part of the buffer could be
165 * written, the remainder is put into the chunk queue for that client.
166 */
167 void send_chunk(struct sender_client *sc, struct sender_status *ss,
168 size_t max_bytes_per_write, long unsigned current_chunk,
169 const char *buf, size_t len)
170 {
171 int ret;
172
173 if (!sc->header_sent && current_chunk) {
174 size_t header_len;
175 char *header_buf = vss_get_header(&header_len);
176 if (header_buf && header_len > 0) {
177 ret = queue_chunk_or_shutdown(sc, ss, -1U, 0);
178 if (ret < 0)
179 goto out;
180 }
181 sc->header_sent = 1;
182 }
183 ret = send_queued_chunks(sc, max_bytes_per_write);
184 if (ret < 0) {
185 shutdown_client(sc, ss);
186 goto out;
187 }
188 if (!len)
189 goto out;
190 if (!ret) { /* still data left in the queue */
191 ret = queue_chunk_or_shutdown(sc, ss, current_chunk, 0);
192 goto out;
193 }
194 ret = write_nonblock(sc->fd, buf, len, max_bytes_per_write);
195 if (ret < 0) {
196 shutdown_client(sc, ss);
197 goto out;
198 }
199 if (ret != len)
200 ret = queue_chunk_or_shutdown(sc, ss, current_chunk, ret);
201 out:
202 if (ret < 0)
203 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
204 }
205
206 void init_sender_status(struct sender_status *ss, char **access_arg,
207 int num_access_args, int port, int max_clients, int default_deny)
208 {
209 ss->listen_fd = -1;
210 INIT_LIST_HEAD(&ss->client_list);
211 ss->port = port;
212 acl_init(&ss->acl, access_arg, num_access_args);
213 ss->num_clients = 0;
214 ss->max_clients = max_clients;
215 ss->default_deny = default_deny;
216 }
217
218 char *get_sender_info(struct sender_status *ss, char *name)
219 {
220 char *clnts = NULL, *ret;
221 struct sender_client *sc, *tmp_sc;
222
223 char *acl_contents = acl_get_contents(&ss->acl);
224 list_for_each_entry_safe(sc, tmp_sc, &ss->client_list, node) {
225 char *tmp = make_message("%s%s ", clnts? clnts : "", sc->name);
226 free(clnts);
227 clnts = tmp;
228 }
229 ret = make_message(
230 "%s sender:\n"
231 "\tstatus: %s\n"
232 "\tport: %d\n"
233 "\tnumber of connected clients: %d\n"
234 "\tmaximal number of clients: %d%s\n"
235 "\tconnected clients: %s\n"
236 "\taccess %s list: %s\n",
237 name,
238 (ss->listen_fd >= 0)? "on" : "off",
239 ss->port,
240 ss->num_clients,
241 ss->max_clients,
242 ss->max_clients > 0? "" : " (unlimited)",
243 clnts? clnts : "(none)",
244 ss->default_deny? "allow" : "deny",
245 acl_contents? acl_contents : "(empty)"
246 );
247 free(acl_contents);
248 free(clnts);
249 return ret;
250 }
251
252 void generic_com_allow(struct sender_command_data *scd,
253 struct sender_status *ss)
254 {
255 acl_allow(scd->addr, scd->netmask, &ss->acl, ss->default_deny);
256 }
257
258 void generic_com_deny(struct sender_command_data *scd,
259 struct sender_status *ss)
260 {
261 acl_deny(scd->addr, scd->netmask, &ss->acl, ss->default_deny);
262 }
263
264 int generic_com_on(struct sender_status *ss, unsigned protocol)
265 {
266 int ret;
267
268 if (ss->listen_fd >= 0)
269 return 1;
270 ret = open_sender(protocol, ss->port);
271 if (ret < 0)
272 return ret;
273 ss->listen_fd = ret;
274 return 1;
275 }
276
277 void generic_com_off(struct sender_status *ss)
278 {
279 if (ss->listen_fd < 0)
280 return;
281 PARA_NOTICE_LOG("closing port %d\n", ss->port);
282 close(ss->listen_fd);
283 del_close_on_fork_list(ss->listen_fd);
284 shutdown_clients(ss);
285 ss->listen_fd = -1;
286 }
287
288 struct sender_client *accept_sender_client(struct sender_status *ss)
289 {
290 struct sender_client *sc;
291 int fd, ret = para_accept(ss->listen_fd, NULL, 0);
292 if (ret < 0) {
293 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
294 return NULL;
295 }
296 fd = ret;
297 ret = -E_MAX_CLIENTS;
298 if (ss->max_clients > 0 && ss->num_clients >= ss->max_clients)
299 goto err_out;
300 ret = mark_fd_nonblocking(fd);
301 if (ret < 0)
302 goto err_out;
303 ret = acl_check_access(fd, &ss->acl, ss->default_deny);
304 if (ret < 0)
305 goto err_out;
306 ss->num_clients++;
307 sc = para_calloc(sizeof(*sc));
308 sc->fd = fd;
309 sc->name = make_message("%s", remote_name(fd));
310 sc->cq = cq_new(MAX_CQ_BYTES);
311 para_list_add(&sc->node, &ss->client_list);
312 add_close_on_fork_list(fd);
313 PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss->num_clients,
314 sc->name, fd);
315 return sc;
316 err_out:
317 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
318 close(fd);
319 return NULL;
320 }
321
322 char *generic_sender_help(void)
323 {
324 return make_message(
325 "usage: {on|off}\n"
326 "usage: {allow|deny} IP mask\n"
327 "example: allow 127.0.0.1 32\n"
328 );
329 }