Merge branch 'refs/heads/t/tarball-build-fix'
[paraslash.git] / send.h
1 /*
2 * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file send.h Sender-related defines and structures. */
8
9 /** The sender subcommands. */
10 enum sender_subcommand {
11 SENDER_ADD, /**< Add a target (udp only). */
12 SENDER_DELETE, /**< Delete a target (udp only). */
13 SENDER_ALLOW, /**< Allow connections from given IP address(es). */
14 SENDER_DENY, /**< Deny connections from given IP address(es). */
15 SENDER_ON, /**< Activate the sender. */
16 SENDER_OFF, /**< Deactivate the sender. */
17 NUM_SENDER_CMDS /**< Used as array size in struct \ref sender. */
18 };
19
20 /**
21 * Describes one supported sender of para_server.
22 *
23 * \sa http_send.c udp_send.c, dccp_send.c.
24 */
25 struct sender {
26 /** The name of the sender. */
27 const char *name;
28 /**
29 * The init function of this sender.
30 *
31 * It must fill in all function pointers of \a s as well as the \a
32 * client_cmds array, see below. It should also do all necessary
33 * preparations to init this sending facility, for example it could
34 * open a tcp port.
35 */
36 void (*init)(struct sender *s);
37 /**
38 * Return the help text of this sender.
39 *
40 * The result must be dynamically allocated and is freed by the caller.
41 */
42 char* (*help)(void);
43 /**
44 * Return current status info about this sender.
45 *
46 * The result must be dynamically allocated and is freed by the caller.
47 */
48 char* (*status)(void);
49 /**
50 * The send-hook.
51 *
52 * It gets called whenever para_server is playing and the current
53 * audio format handler indicates that another chunk of data should
54 * be sent now. The two parameters \a current_chunk and \a chunks_sent
55 * only differ if the stream was repositioned by the \a ff or \a jmp
56 * command. Of course, \a buf is a pointer to the chunk of data which
57 * should be sent, and \a len is the length of this buffer.
58 */
59 void (*send)(long unsigned current_chunk, long unsigned chunks_sent,
60 const char *buf, size_t len, const char *header_buf,
61 size_t header_len);
62 /**
63 * Add file descriptors to fd_sets.
64 *
65 * The pre_select function of each supported sender is called just before
66 * para_server enters its main select loop. Each sender may add its own
67 * file descriptors to the \a rfds or the \a wfds set.
68 *
69 * If a file descriptor was added, \a max_fileno must be increased by
70 * this function, if necessary.
71 *
72 * \sa select(2).
73 */
74 void (*pre_select)(int *max_fileno, fd_set *rfds, fd_set *wfds);
75 /**
76 * Handle the file descriptors which are ready for I/O.
77 *
78 * If the pre_select hook added one ore more file descriptors to the
79 * read or write set, this is the hook to check the result and do any
80 * I/O on those descriptors which are ready for reading/writing.
81 */
82 void (*post_select)(fd_set *rfds, fd_set *wfds);
83 /**
84 * Terminate all connected clients.
85 *
86 * This is called e.g. if the stop command was executed. It should make
87 * the clients aware of the end-of-file condition.
88 */
89 void (*shutdown_clients)(void);
90 /**
91 * Array of function pointers for the sender subcommands.
92 *
93 * Each sender may implement any subset of the sender commands by
94 * filling in the appropriate function pointer in the array. A \p NULL
95 * pointer means this command is not implemented by this sender.
96 */
97 int (*client_cmds[NUM_SENDER_CMDS])(struct sender_command_data*);
98 /**
99 * Resolve target-specific URL string
100 *
101 * This method must be defined if the sender supports the add/delete
102 * subcommands. It interprets a string specifying a target URL in a
103 * sender-specific fashion (e.g. embedded FEC string). It can also
104 * fill in sender-specific defaults if necessary.
105 */
106 int (*resolve_target)(const char *, struct sender_command_data *);
107 };
108
109 /** Describes one client, connected to a paraslash sender. */
110 struct sender_client {
111 /** The file descriptor of the client. */
112 int fd;
113 /** The socket "name" of the client. */
114 char *name;
115 /** The position of this client in the client list. */
116 struct list_head node;
117 /** Non-zero if audio file header has been sent. */
118 int header_sent;
119 /** The list of pending chunks for this client. */
120 struct chunk_queue *cq;
121 /** Data specific to the particular sender. */
122 void *private_data;
123 };
124
125 /**
126 * Each paraslash sender may register arbitrary many clients to the virtual
127 * streaming system, possibly with varying fec parameters. In order to do so,
128 * it must allocate a \a fec_client_parms structure and pass it to \ref
129 * vss_add_fec_client.
130 *
131 * Clients are automatically removed from that list by the vss if an error
132 * occurs, or if the sender requests deletion of a client by calling \ref
133 * vss_del_fec_client().
134 */
135
136 /** FEC parameters requested by FEC clients. */
137 struct fec_client_parms {
138 /** Number of data slices plus redundant slices. */
139 uint8_t slices_per_group;
140 /** Number of slices minus number of redundant slices. */
141 uint8_t data_slices_per_group;
142 /** Whether the header must be sent periodically. */
143 bool need_periodic_header;
144 /**
145 * Transport-layer initialisation for FEC support.
146 *
147 * This optional function serves (a) to make the transport layer
148 * ready to send FEC slices and (b) to determine the Maximum
149 * Packet Size (MPS) supported by the connection. The MPS value
150 * determines the largest payload size. This value is used to
151 * send FEC slices that are not larger than the path MTU, to avoid
152 * fragmentation and to maximize packet utilization. The user can
153 * alternatively specify a slice size of up to this value.
154 */
155 int (*init_fec)(struct sender_client *sc);
156 /** Push out FEC-encoded packets */
157 void (*send_fec)(struct sender_client *sc, char *buf, size_t len);
158 };
159
160 /** Describes the current status of one paraslash sender. */
161 struct sender_status {
162 /** The file descriptor of the socket this sender is listening on. */
163 int listen_fd;
164 /** The TCP/DCCP port used by this sender. */
165 int port;
166 /** The current number of simultaneous connections. */
167 int num_clients;
168 /** The maximal number of simultaneous connections. */
169 int max_clients;
170 /** Whether the access control list is a whitelist. */
171 int default_deny;
172 /** The whitelist/blacklist. */
173 struct list_head acl;
174 /** The list of connected clients. */
175 struct list_head client_list;
176 };
177
178 void shutdown_client(struct sender_client *sc, struct sender_status *ss);
179 void shutdown_clients(struct sender_status *ss);
180 void init_sender_status(struct sender_status *ss, char **access_arg, int num_access_args,
181 int port, int max_clients, int default_deny);
182 char *generic_sender_status(struct sender_status *ss, const char *name);
183
184 void generic_com_allow(struct sender_command_data *scd,
185 struct sender_status *ss);
186 void generic_com_deny(struct sender_command_data *scd,
187 struct sender_status *ss);
188 int generic_com_on(struct sender_status *ss, unsigned protocol);
189 void generic_com_off(struct sender_status *ss);
190 char *generic_sender_help(void);
191 struct sender_client *accept_sender_client(struct sender_status *ss, fd_set *rfds);
192 int send_queued_chunks(int fd, struct chunk_queue *cq);
193 int parse_fec_url(const char *arg, struct sender_command_data *scd);