dccp: integrate new fec interaction
[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 /** Do not write more than that many bytes at once. */
36 #define DCCP_MAX_BYTES_PER_WRITE 1024
37
38 static struct sender_status dccp_sender_status, *dss = &dccp_sender_status;
39
40 struct dccp_fec_client {
41 struct fec_client_parms fcp;
42 struct fec_client *fc;
43 };
44
45 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
46 __a_unused fd_set *wfds)
47 {
48 if (dss->listen_fd >= 0)
49 para_fd_set(dss->listen_fd, rfds, max_fileno);
50 }
51
52 /**
53 * Query the TX CCID used on the sender-client half connection.
54 * \param sockfd Server socket descriptor to query (after accept(2)).
55 * \return CCID number > 0, -1 on error/incompatibility.
56 *
57 * NB: This feature is only available on Linux > 2.6.30; on older kernels
58 * ENOPROTOOPT ("Protocol not available") will be returned.
59 */
60 static int dccp_get_tx_ccid(int sockfd)
61 {
62 int tx_ccid;
63 socklen_t len = sizeof(tx_ccid);
64
65 if (getsockopt(sockfd, SOL_DCCP,
66 DCCP_SOCKOPT_TX_CCID, &tx_ccid, &len) < 0) {
67 PARA_WARNING_LOG("DCCP_SOCKOPT_TX_CCID: %s\n", strerror(errno));
68 return -1;
69 }
70 return tx_ccid;
71 }
72
73 static void dccp_shutdown_client(struct sender_client *sc)
74 {
75 struct dccp_fec_client *dfc = sc->private_data;
76
77 vss_del_fec_client(dfc->fc);
78 shutdown_client(sc, dss);
79 }
80
81 static void dccp_shutdown_clients(void)
82 {
83 struct sender_client *sc, *tmp;
84
85 list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
86 dccp_shutdown_client(sc);
87 }
88
89 static int dccp_send_fec(struct sender_client *sc, char *buf, size_t len)
90 {
91 int ret = write_nonblock(sc->fd, buf, len, DCCP_MAX_BYTES_PER_WRITE);
92
93 if (ret < 0)
94 dccp_shutdown_client(sc);
95 return ret;
96 }
97
98 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
99 {
100 struct sender_client *sc;
101 struct dccp_fec_client *dfc;
102 int tx_ccid;
103
104 sc = accept_sender_client(dss, rfds);
105 if (!sc)
106 return;
107
108 /* If CCID identifiable, present client as <host>#<port>~<ccid> */
109 tx_ccid = dccp_get_tx_ccid(sc->fd);
110 if (tx_ccid != -1) {
111 char *tmp = make_message("%s~%d", sc->name, tx_ccid);
112
113 free(sc->name);
114 sc->name = tmp;
115 }
116 /*
117 * Bypass unused CCID paths: the sender does not receive application data
118 * from the client; by shutting down this unused communication path we can
119 * reduce processing costs a bit. See analogous comment in dccp_recv.c.
120 */
121 if (shutdown(sc->fd, SHUT_RD) < 0) {
122 PARA_WARNING_LOG("%s\n", strerror(errno));
123 shutdown_client(sc, dss);
124 return;
125 }
126 dfc = para_calloc(sizeof(*dfc));
127 sc->private_data = dfc;
128 dfc->fcp.slices_per_group = 4;
129 dfc->fcp.data_slices_per_group = 3;
130 dfc->fcp.max_slice_bytes = DCCP_MAX_BYTES_PER_WRITE; /* FIXME */
131 dfc->fcp.init_fec = NULL; /* FIXME */
132 dfc->fcp.send_fec = dccp_send_fec;
133 dfc->fc = vss_add_fec_client(sc, &dfc->fcp);
134 }
135
136 static int dccp_com_on(__a_unused struct sender_command_data *scd)
137 {
138 return generic_com_on(dss, IPPROTO_DCCP);
139 }
140
141 static int dccp_com_off(__a_unused struct sender_command_data *scd)
142 {
143 generic_com_off(dss);
144 return 1;
145 }
146
147
148 static int dccp_com_deny(struct sender_command_data *scd)
149 {
150 generic_com_deny(scd, dss);
151 return 1;
152 }
153
154 static int dccp_com_allow(struct sender_command_data *scd)
155 {
156 generic_com_allow(scd, dss);
157 return 1;
158 }
159
160 /**
161 * Return list of available CCIDs or warning, in static buffer.
162 */
163 static const char *dccp_list_available_ccids(void)
164 {
165 /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
166 static char list[DCCP_MAX_HOST_CCIDS * 4];
167 uint8_t *ccids;
168 int i, len, nccids;
169
170 nccids = dccp_available_ccids(&ccids);
171 if (nccids < 0) {
172 snprintf(list, sizeof(list), "Unable to query available CCIDs");
173 } else {
174 for (i = len = 0; i < nccids; i++)
175 len += snprintf(list + len, sizeof(list) - len,
176 "%s%d", i ? " " : "", ccids[i]);
177 }
178 return list;
179 }
180
181 static char *dccp_info(void)
182 {
183 char *info = get_sender_info(dss, "dccp");
184 char *ret = make_message("%s" "\tsupported ccids: %s\n",
185 info, dccp_list_available_ccids());
186 free(info);
187 return ret;
188 }
189
190 /**
191 * The init function of the dccp sender.
192 *
193 * \param s pointer to the dccp sender struct.
194 *
195 * It initializes all function pointers of \a s and starts
196 * listening on the given port.
197 */
198 void dccp_send_init(struct sender *s)
199 {
200 int ret;
201
202 s->info = dccp_info;
203 s->send = NULL;
204 s->pre_select = dccp_pre_select;
205 s->post_select = dccp_post_select;
206 s->shutdown_clients = dccp_shutdown_clients;
207 s->help = generic_sender_help;
208 s->client_cmds[SENDER_ON] = dccp_com_on;
209 s->client_cmds[SENDER_OFF] = dccp_com_off;
210 s->client_cmds[SENDER_DENY] = dccp_com_deny;
211 s->client_cmds[SENDER_ALLOW] = dccp_com_allow;
212 s->client_cmds[SENDER_ADD] = NULL;
213 s->client_cmds[SENDER_DELETE] = NULL;
214
215 init_sender_status(dss, conf.dccp_access_arg, conf.dccp_access_given,
216 conf.dccp_port_arg, conf.dccp_max_clients_arg,
217 conf.dccp_default_deny_given);
218 ret = generic_com_on(dss, IPPROTO_DCCP);
219 if (ret < 0)
220 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
221 }