para.h: Fix typo in comment.
[paraslash.git] / dccp_send.c
1 /*
2 * Copyright (C) 2006-2010 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 <regex.h>
15 #include <sys/types.h>
16 #include <dirent.h>
17 #include <osl.h>
18
19 #include "para.h"
20 #include "error.h"
21 #include "string.h"
22 #include "afh.h"
23 #include "afs.h"
24 #include "server.h"
25 #include "net.h"
26 #include "list.h"
27 #include "send.h"
28 #include "vss.h"
29 #include "fd.h"
30 #include "close_on_fork.h"
31 #include "chunk_queue.h"
32 #include "server.cmdline.h"
33 #include "acl.h"
34
35 static struct sender_status dccp_sender_status, *dss = &dccp_sender_status;
36
37 struct dccp_fec_client {
38 struct fec_client_parms fcp;
39 struct fec_client *fc;
40 };
41
42 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
43 __a_unused fd_set *wfds)
44 {
45 if (dss->listen_fd >= 0)
46 para_fd_set(dss->listen_fd, rfds, max_fileno);
47 }
48
49 /**
50 * Query the TX CCID used on the sender-client half connection.
51 * \param sockfd Server socket descriptor to query (after accept(2)).
52 * \return CCID number > 0, -1 on error/incompatibility.
53 *
54 * NB: This feature is only available on Linux > 2.6.30; on older kernels
55 * ENOPROTOOPT ("Protocol not available") will be returned.
56 */
57 static int dccp_get_tx_ccid(int sockfd)
58 {
59 int tx_ccid;
60 socklen_t len = sizeof(tx_ccid);
61
62 if (getsockopt(sockfd, SOL_DCCP,
63 DCCP_SOCKOPT_TX_CCID, &tx_ccid, &len) < 0) {
64 PARA_WARNING_LOG("DCCP_SOCKOPT_TX_CCID: %s\n", strerror(errno));
65 return -1;
66 }
67 return tx_ccid;
68 }
69
70 static void dccp_shutdown_client(struct sender_client *sc)
71 {
72 struct dccp_fec_client *dfc = sc->private_data;
73
74 vss_del_fec_client(dfc->fc);
75 shutdown_client(sc, dss);
76 }
77
78 static void dccp_shutdown_clients(void)
79 {
80 struct sender_client *sc, *tmp;
81
82 list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
83 dccp_shutdown_client(sc);
84 }
85
86 /** * Obtain current MPS according to RFC 4340, sec. 14. */
87 static int dccp_init_fec(struct sender_client *sc)
88 {
89 int mps, ret;
90 socklen_t ml = sizeof(mps);
91
92 /* If call fails, return some sensible minimum value */
93 ret = getsockopt(sc->fd, SOL_DCCP, DCCP_SOCKOPT_GET_CUR_MPS, &mps, &ml);
94 if (ret < 0) {
95 PARA_NOTICE_LOG("can not determine MPS: %s\n", strerror(errno));
96 mps = generic_max_transport_msg_size(sc->fd) - DCCP_MAX_HEADER;
97 }
98 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
99 assert(mps > 0);
100 if (conf.dccp_max_slice_size_arg > 0)
101 mps = PARA_MIN(mps, conf.dccp_max_slice_size_arg);
102 return mps;
103 }
104
105 static int dccp_send_fec(struct sender_client *sc, char *buf, size_t len)
106 {
107 int ret = write_nonblock(sc->fd, buf, len);
108
109 if (ret < 0)
110 dccp_shutdown_client(sc);
111 return ret;
112 }
113
114 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
115 {
116 struct sender_client *sc;
117 struct dccp_fec_client *dfc;
118 int tx_ccid;
119
120 sc = accept_sender_client(dss, rfds);
121 if (!sc)
122 return;
123
124 /* If CCID identifiable, present client as <host>#<port>~<ccid> */
125 tx_ccid = dccp_get_tx_ccid(sc->fd);
126 if (tx_ccid != -1) {
127 char *tmp = make_message("%s~%d", sc->name, tx_ccid);
128
129 free(sc->name);
130 sc->name = tmp;
131 }
132 /*
133 * Bypass unused CCID paths: the sender does not receive application data
134 * from the client; by shutting down this unused communication path we can
135 * reduce processing costs a bit. See analogous comment in dccp_recv.c.
136 */
137 if (shutdown(sc->fd, SHUT_RD) < 0) {
138 PARA_WARNING_LOG("%s\n", strerror(errno));
139 shutdown_client(sc, dss);
140 return;
141 }
142 dfc = para_calloc(sizeof(*dfc));
143 sc->private_data = dfc;
144 dfc->fcp.data_slices_per_group = conf.dccp_data_slices_per_group_arg;
145 dfc->fcp.slices_per_group = conf.dccp_slices_per_group_arg;
146 dfc->fcp.init_fec = dccp_init_fec;
147 dfc->fcp.send_fec = dccp_send_fec;
148 dfc->fc = vss_add_fec_client(sc, &dfc->fcp);
149 }
150
151 static int dccp_com_on(__a_unused struct sender_command_data *scd)
152 {
153 return generic_com_on(dss, IPPROTO_DCCP);
154 }
155
156 static int dccp_com_off(__a_unused struct sender_command_data *scd)
157 {
158 dccp_shutdown_clients();
159 generic_com_off(dss);
160 return 1;
161 }
162
163
164 static int dccp_com_deny(struct sender_command_data *scd)
165 {
166 generic_com_deny(scd, dss);
167 return 1;
168 }
169
170 static int dccp_com_allow(struct sender_command_data *scd)
171 {
172 generic_com_allow(scd, dss);
173 return 1;
174 }
175
176 /**
177 * Return list of available CCIDs or warning, in static buffer.
178 */
179 static const char *dccp_list_available_ccids(void)
180 {
181 /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
182 static char list[DCCP_MAX_HOST_CCIDS * 4];
183 uint8_t *ccids;
184 int i, len, nccids;
185
186 nccids = dccp_available_ccids(&ccids);
187 if (nccids < 0) {
188 snprintf(list, sizeof(list), "Unable to query available CCIDs");
189 } else {
190 for (i = len = 0; i < nccids; i++)
191 len += snprintf(list + len, sizeof(list) - len,
192 "%s%d", i ? " " : "", ccids[i]);
193 }
194 return list;
195 }
196
197 static char *dccp_info(void)
198 {
199 char *info = get_sender_info(dss, "dccp");
200 char *ret = make_message("%s" "\tsupported ccids: %s\n",
201 info, dccp_list_available_ccids());
202 free(info);
203 return ret;
204 }
205
206 /**
207 * The init function of the dccp sender.
208 *
209 * \param s pointer to the dccp sender struct.
210 *
211 * It initializes all function pointers of \a s and starts
212 * listening on the given port.
213 */
214 void dccp_send_init(struct sender *s)
215 {
216 int ret, k, n;
217
218 s->info = dccp_info;
219 s->send = NULL;
220 s->pre_select = dccp_pre_select;
221 s->post_select = dccp_post_select;
222 s->shutdown_clients = dccp_shutdown_clients;
223 s->resolve_target = NULL;
224 s->help = generic_sender_help;
225 s->client_cmds[SENDER_ON] = dccp_com_on;
226 s->client_cmds[SENDER_OFF] = dccp_com_off;
227 s->client_cmds[SENDER_DENY] = dccp_com_deny;
228 s->client_cmds[SENDER_ALLOW] = dccp_com_allow;
229 s->client_cmds[SENDER_ADD] = NULL;
230 s->client_cmds[SENDER_DELETE] = NULL;
231
232 k = conf.dccp_data_slices_per_group_arg;
233 n = conf.dccp_slices_per_group_arg;
234
235 if (k <= 0 || n <= 0 || k >= n) {
236 PARA_WARNING_LOG("invalid FEC parameters, using defaults\n");
237 conf.dccp_data_slices_per_group_arg = 3;
238 conf.dccp_slices_per_group_arg = 4;
239 }
240
241 init_sender_status(dss, conf.dccp_access_arg, conf.dccp_access_given,
242 conf.dccp_port_arg, conf.dccp_max_clients_arg,
243 conf.dccp_default_deny_given);
244 ret = generic_com_on(dss, IPPROTO_DCCP);
245 if (ret < 0)
246 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
247 }