2 * Copyright (C) 2006-2013 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file dccp_send.c Paraslash's dccp sender. */
10 * based on server.c of dccp-cs-0.01.tar.bz2,
11 * (C) 2005 Ian McDonald <imcdnzl@gmail.com>
14 #include <netinet/in.h>
15 #include <sys/socket.h>
17 #include <sys/types.h>
19 #include <arpa/inet.h>
35 #include "close_on_fork.h"
36 #include "chunk_queue.h"
37 #include "server.cmdline.h"
40 static struct sender_status dccp_sender_status
, *dss
= &dccp_sender_status
;
42 struct dccp_fec_client
{
43 struct fec_client_parms fcp
;
44 struct fec_client
*fc
;
47 static void dccp_pre_select(int *max_fileno
, fd_set
*rfds
,
48 __a_unused fd_set
*wfds
)
50 if (dss
->listen_fd
>= 0)
51 para_fd_set(dss
->listen_fd
, rfds
, max_fileno
);
55 * Query the TX CCID used on the sender-client half connection.
56 * \param sockfd Server socket descriptor to query (after accept(2)).
57 * \return CCID number > 0, -1 on error/incompatibility.
59 * NB: This feature is only available on Linux > 2.6.30; on older kernels
60 * ENOPROTOOPT ("Protocol not available") will be returned.
62 static int dccp_get_tx_ccid(int sockfd
)
65 socklen_t len
= sizeof(tx_ccid
);
67 if (getsockopt(sockfd
, SOL_DCCP
,
68 DCCP_SOCKOPT_TX_CCID
, &tx_ccid
, &len
) < 0) {
69 PARA_WARNING_LOG("DCCP_SOCKOPT_TX_CCID: %s\n", strerror(errno
));
75 static void dccp_shutdown_client(struct sender_client
*sc
)
77 struct dccp_fec_client
*dfc
= sc
->private_data
;
79 vss_del_fec_client(dfc
->fc
);
80 shutdown_client(sc
, dss
);
83 static void dccp_shutdown_clients(void)
85 struct sender_client
*sc
, *tmp
;
87 list_for_each_entry_safe(sc
, tmp
, &dss
->client_list
, node
)
88 dccp_shutdown_client(sc
);
91 /** * Obtain current MPS according to RFC 4340, sec. 14. */
92 static int dccp_init_fec(struct sender_client
*sc
)
95 socklen_t ml
= sizeof(mps
);
97 /* If call fails, return some sensible minimum value */
98 ret
= getsockopt(sc
->fd
, SOL_DCCP
, DCCP_SOCKOPT_GET_CUR_MPS
, &mps
, &ml
);
100 PARA_NOTICE_LOG("can not determine MPS: %s\n", strerror(errno
));
101 mps
= generic_max_transport_msg_size(sc
->fd
) - DCCP_MAX_HEADER
;
103 PARA_INFO_LOG("current MPS = %d bytes\n", mps
);
105 if (conf
.dccp_max_slice_size_arg
> 0)
106 mps
= PARA_MIN(mps
, conf
.dccp_max_slice_size_arg
);
110 static void dccp_send_fec(struct sender_client
*sc
, char *buf
, size_t len
)
112 int ret
= xwrite(sc
->fd
, buf
, len
);
115 dccp_shutdown_client(sc
);
118 static void dccp_post_select(fd_set
*rfds
, __a_unused fd_set
*wfds
)
120 struct sender_client
*sc
;
121 struct dccp_fec_client
*dfc
;
124 sc
= accept_sender_client(dss
, rfds
);
128 /* If CCID identifiable, present client as <host>#<port>~<ccid> */
129 tx_ccid
= dccp_get_tx_ccid(sc
->fd
);
131 char *tmp
= make_message("%s~%d", sc
->name
, tx_ccid
);
137 * Bypass unused CCID paths: the sender does not receive application data
138 * from the client; by shutting down this unused communication path we can
139 * reduce processing costs a bit. See analogous comment in dccp_recv.c.
141 if (shutdown(sc
->fd
, SHUT_RD
) < 0) {
142 PARA_WARNING_LOG("%s\n", strerror(errno
));
143 shutdown_client(sc
, dss
);
146 dfc
= para_calloc(sizeof(*dfc
));
147 sc
->private_data
= dfc
;
148 dfc
->fcp
.data_slices_per_group
= conf
.dccp_data_slices_per_group_arg
;
149 dfc
->fcp
.slices_per_group
= conf
.dccp_slices_per_group_arg
;
150 dfc
->fcp
.init_fec
= dccp_init_fec
;
151 dfc
->fcp
.send_fec
= dccp_send_fec
;
152 dfc
->fcp
.need_periodic_header
= false;
153 dfc
->fc
= vss_add_fec_client(sc
, &dfc
->fcp
);
156 static int dccp_com_on(__a_unused
struct sender_command_data
*scd
)
158 return generic_com_on(dss
, IPPROTO_DCCP
);
161 static int dccp_com_off(__a_unused
struct sender_command_data
*scd
)
163 dccp_shutdown_clients();
164 generic_com_off(dss
);
169 static int dccp_com_deny(struct sender_command_data
*scd
)
171 generic_com_deny(scd
, dss
);
175 static int dccp_com_allow(struct sender_command_data
*scd
)
177 generic_com_allow(scd
, dss
);
182 * Return list of available CCIDs or warning, in static buffer.
184 static const char *dccp_list_available_ccids(void)
186 /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
187 static char list
[DCCP_MAX_HOST_CCIDS
* 4];
191 nccids
= dccp_available_ccids(&ccids
);
193 snprintf(list
, sizeof(list
), "Unable to query available CCIDs");
195 for (i
= len
= 0; i
< nccids
; i
++)
196 len
+= snprintf(list
+ len
, sizeof(list
) - len
,
197 "%s%d", i
? " " : "", ccids
[i
]);
202 static char *dccp_info(void)
204 char *info
= get_sender_info(dss
, "dccp");
205 char *ret
= make_message("%s" "\tsupported ccids: %s\n",
206 info
, dccp_list_available_ccids());
212 * The init function of the dccp sender.
214 * \param s pointer to the dccp sender struct.
216 * It initializes all function pointers of \a s and starts
217 * listening on the given port.
219 void dccp_send_init(struct sender
*s
)
225 s
->pre_select
= dccp_pre_select
;
226 s
->post_select
= dccp_post_select
;
227 s
->shutdown_clients
= dccp_shutdown_clients
;
228 s
->resolve_target
= NULL
;
229 s
->help
= generic_sender_help
;
230 s
->client_cmds
[SENDER_ON
] = dccp_com_on
;
231 s
->client_cmds
[SENDER_OFF
] = dccp_com_off
;
232 s
->client_cmds
[SENDER_DENY
] = dccp_com_deny
;
233 s
->client_cmds
[SENDER_ALLOW
] = dccp_com_allow
;
234 s
->client_cmds
[SENDER_ADD
] = NULL
;
235 s
->client_cmds
[SENDER_DELETE
] = NULL
;
237 k
= conf
.dccp_data_slices_per_group_arg
;
238 n
= conf
.dccp_slices_per_group_arg
;
240 if (k
<= 0 || n
<= 0 || k
>= n
) {
241 PARA_WARNING_LOG("invalid FEC parameters, using defaults\n");
242 conf
.dccp_data_slices_per_group_arg
= 3;
243 conf
.dccp_slices_per_group_arg
= 4;
246 init_sender_status(dss
, conf
.dccp_access_arg
, conf
.dccp_access_given
,
247 conf
.dccp_port_arg
, conf
.dccp_max_clients_arg
,
248 conf
.dccp_default_deny_given
);
249 ret
= generic_com_on(dss
, IPPROTO_DCCP
);
251 PARA_ERROR_LOG("%s\n", para_strerror(-ret
));