1 /* Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
3 /** \file dccp_send.c Paraslash's dccp sender. */
6 * based on server.c of dccp-cs-0.01.tar.bz2,
7 * (C) 2005 Ian McDonald <imcdnzl@gmail.com>
10 #include <netinet/in.h>
11 #include <sys/socket.h>
13 #include <sys/types.h>
14 #include <arpa/inet.h>
19 #include "server.lsg.h"
31 #include "close_on_fork.h"
32 #include "chunk_queue.h"
35 static struct sender_status dccp_sender_status, *dss = &dccp_sender_status;
37 struct dccp_fec_client {
38 struct fec_client_parms fcp;
39 struct fec_client *fc;
42 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
43 __a_unused fd_set *wfds)
45 if (dss->listen_fd >= 0)
46 para_fd_set(dss->listen_fd, rfds, max_fileno);
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.
54 * NB: This feature is only available on Linux > 2.6.30; on older kernels
55 * ENOPROTOOPT ("Protocol not available") will be returned.
57 static int dccp_get_tx_ccid(int sockfd)
60 socklen_t len = sizeof(tx_ccid);
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));
70 static void dccp_shutdown_client(struct sender_client *sc)
72 struct dccp_fec_client *dfc = sc->private_data;
74 vss_del_fec_client(dfc->fc);
75 shutdown_client(sc, dss);
78 static void dccp_shutdown_clients(void)
80 struct sender_client *sc, *tmp;
82 list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
83 dccp_shutdown_client(sc);
86 /** * Obtain current MPS according to RFC 4340, sec. 14. */
87 static int dccp_init_fec(struct sender_client *sc)
90 socklen_t ml = sizeof(mps);
91 uint32_t mss; /* max slize size */
93 /* If call fails, return some sensible minimum value */
94 ret = getsockopt(sc->fd, SOL_DCCP, DCCP_SOCKOPT_GET_CUR_MPS, &mps, &ml);
96 PARA_NOTICE_LOG("can not determine MPS: %s\n", strerror(errno));
97 mps = generic_max_transport_msg_size(sc->fd) - DCCP_MAX_HEADER;
99 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
101 mss = OPT_UINT32_VAL(DCCP_MAX_SLICE_SIZE);
102 if (mss > 0 && mss <= INT_MAX)
103 mps = PARA_MIN(mps, (int)mss);
107 static void dccp_send_fec(struct sender_client *sc, char *buf, size_t len)
109 int ret = xwrite(sc->fd, buf, len);
112 dccp_shutdown_client(sc);
115 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
117 struct sender_client *sc;
118 struct dccp_fec_client *dfc;
122 sc = accept_sender_client(dss, rfds);
126 /* If CCID identifiable, present client as <host>#<port>~<ccid> */
127 tx_ccid = dccp_get_tx_ccid(sc->fd);
129 char *tmp = make_message("%s~%d", sc->name, tx_ccid);
135 * Bypass unused CCID paths: the sender does not receive application data
136 * from the client; by shutting down this unused communication path we can
137 * reduce processing costs a bit. See analogous comment in \ref dccp_recv.c.
139 if (shutdown(sc->fd, SHUT_RD) < 0) {
140 PARA_WARNING_LOG("%s\n", strerror(errno));
141 shutdown_client(sc, dss);
144 dfc = para_calloc(sizeof(*dfc));
145 sc->private_data = dfc;
146 k = OPT_UINT32_VAL(DCCP_DATA_SLICES_PER_GROUP);
147 n = OPT_UINT32_VAL(DCCP_SLICES_PER_GROUP);
148 if (k == 0 || n == 0 || k >= n) {
149 PARA_WARNING_LOG("invalid FEC parameters, using defaults\n");
150 dfc->fcp.data_slices_per_group = 3;
151 dfc->fcp.slices_per_group = 4;
153 dfc->fcp.data_slices_per_group = k;
154 dfc->fcp.slices_per_group = n;
156 dfc->fcp.init_fec = dccp_init_fec;
157 dfc->fcp.send_fec = dccp_send_fec;
158 dfc->fcp.need_periodic_header = false;
159 dfc->fc = vss_add_fec_client(sc, &dfc->fcp);
162 static int dccp_com_on(__a_unused struct sender_command_data *scd)
164 return generic_com_on(dss, IPPROTO_DCCP);
167 static int dccp_com_off(__a_unused struct sender_command_data *scd)
169 dccp_shutdown_clients();
170 generic_com_off(dss);
175 static int dccp_com_deny(struct sender_command_data *scd)
177 generic_com_deny(scd, dss);
181 static int dccp_com_allow(struct sender_command_data *scd)
183 generic_com_allow(scd, dss);
188 * Return list of available CCIDs or warning, in static buffer.
190 static const char *dccp_list_available_ccids(void)
192 /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
193 static char list[DCCP_MAX_HOST_CCIDS * 4];
197 nccids = dccp_available_ccids(&ccids);
199 snprintf(list, sizeof(list), "Unable to query available CCIDs");
201 for (i = len = 0; i < nccids; i++)
202 len += snprintf(list + len, sizeof(list) - len,
203 "%s%d", i ? " " : "", ccids[i]);
208 static char *dccp_status(void)
210 char *status = generic_sender_status(dss, "dccp");
211 char *result = make_message("%ssupported ccids: %s\n", status,
212 dccp_list_available_ccids());
218 * The init function of the dccp sender.
220 * \param s pointer to the dccp sender struct.
222 * It initializes all function pointers of \a s and starts
223 * listening on the given port.
225 void dccp_send_init(struct sender *s)
229 s->status = dccp_status;
231 s->pre_select = dccp_pre_select;
232 s->post_select = dccp_post_select;
233 s->shutdown_clients = dccp_shutdown_clients;
234 s->resolve_target = NULL;
235 s->help = generic_sender_help;
236 s->client_cmds[SENDER_on] = dccp_com_on;
237 s->client_cmds[SENDER_off] = dccp_com_off;
238 s->client_cmds[SENDER_deny] = dccp_com_deny;
239 s->client_cmds[SENDER_allow] = dccp_com_allow;
240 s->client_cmds[SENDER_add] = NULL;
241 s->client_cmds[SENDER_delete] = NULL;
243 init_sender_status(dss, OPT_RESULT(DCCP_ACCESS),
244 OPT_UINT32_VAL(DCCP_PORT), OPT_UINT32_VAL(DCCP_MAX_CLIENTS),
245 OPT_GIVEN(DCCP_DEFAULT_DENY));
246 ret = generic_com_on(dss, IPPROTO_DCCP);
248 PARA_ERROR_LOG("%s\n", para_strerror(-ret));