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[paraslash.git] / send.h
1 /*
2 * Copyright (C) 2005-2011 Andre Noll <maan@systemlinux.org>
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_ADD, SENDER_DELETE, SENDER_ALLOW, SENDER_DENY, SENDER_ON, SENDER_OFF, NUM_SENDER_CMDS};
11
12 /**
13 * Describes one supported sender of para_server.
14 *
15 * \sa http_send.c udp_send.c, dccp_send.c.
16 */
17 struct sender {
18 /** The name of the sender. */
19 const char *name;
20 /**
21 * The init function of this sender.
22 *
23 * It must fill in all function pointers of \a s as well as the \a
24 * client_cmds array, see below. It should also do all necessary
25 * preparations to init this sending facility, for example it could
26 * open a tcp port.
27 */
28 void (*init)(struct sender *s);
29 /**
30 * Return the help text of this sender.
31 *
32 * The result must be dynamically allocated and is freed by the caller.
33 */
34 char* (*help)(void);
35 /**
36 * Return current status info about this sender.
37 *
38 * The result must be dynamically allocated and is freed by the caller.
39 */
40 char* (*info)(void);
41 /**
42 * The send-hook.
43 *
44 * It gets called whenever para_server is playing and the current
45 * audio format handler indicates that another chunk of data should
46 * be sent now. The two parameters \a current_chunk and \a chunks_sent
47 * only differ if the stream was repositioned by the \a ff or \a jmp
48 * command. Of course, \a buf is a pointer to the chunk of data which
49 * should be sent, and \a len is the length of this buffer.
50 */
51 void (*send)(long unsigned current_chunk, long unsigned chunks_sent,
52 const char *buf, size_t len, const char *header_buf,
53 size_t header_len);
54 /**
55 * Add file descriptors to fd_sets.
56 *
57 * The pre_select function of each supported sender is called just before
58 * para_server enters its main select loop. Each sender may add its own
59 * file descriptors to the \a rfds or the \a wfds set.
60 *
61 * If a file descriptor was added, \a max_fileno must be increased by
62 * this function, if necessary.
63 *
64 * \sa select(2).
65 */
66 void (*pre_select)(int *max_fileno, fd_set *rfds, fd_set *wfds);
67 /**
68 * Handle the file descriptors which are ready for I/O.
69 *
70 * If the pre_select hook added one ore more file descriptors to the
71 * read or write set, this is the hook to check the result and do any
72 * I/O on those descriptors which are ready for reading/writing.
73 */
74 void (*post_select)(fd_set *rfds, fd_set *wfds);
75 /**
76 * Terminate all connected clients.
77 *
78 * This is called e.g. if the stop command was executed. It should make
79 * the clients aware of the end-of-file condition.
80 */
81 void (*shutdown_clients)(void);
82 /**
83 * Array of function pointers for the sender subcommands.
84 *
85 * Each sender may implement any subset of the sender commands by
86 * filling in the appropriate function pointer in the array. A \p NULL
87 * pointer means this command is not implemented by this sender.
88 */
89 int (*client_cmds[NUM_SENDER_CMDS])(struct sender_command_data*);
90 /**
91 * Resolve target-specific URL string
92 *
93 * This method must be defined if the sender supports the add/delete
94 * subcommands. It interprets a string specifying a target URL in a
95 * sender-specific fashion (e.g. embedded FEC string). It can also
96 * fill in sender-specific defaults if necessary.
97 */
98 int (*resolve_target)(const char *, struct sender_command_data *);
99 };
100
101 /** Describes one client, connected to a paraslash sender. */
102 struct sender_client {
103 /** The file descriptor of the client. */
104 int fd;
105 /** The socket "name" of the client. */
106 char *name;
107 /** The position of this client in the client list. */
108 struct list_head node;
109 /** Non-zero if audio file header has been sent. */
110 int header_sent;
111 /** The list of pending chunks for this client. */
112 struct chunk_queue *cq;
113 /** Data specific to the particular sender. */
114 void *private_data;
115 };
116
117 /**
118 * Each paraslash sender may register arbitrary many clients to the virtual
119 * streaming system, possibly with varying fec parameters. In order to do so,
120 * it must allocate a \a fec_client_parms structure and pass it to \ref
121 * vss_add_fec_client.
122 *
123 * Clients are automatically removed from that list by the vss if an error
124 * occurs, or if the sender requests deletion of a client by calling \ref
125 * vss_del_fec_client().
126 */
127
128 /** FEC parameters requested by FEC clients. */
129 struct fec_client_parms {
130 /** Number of data slices plus redundant slices. */
131 uint8_t slices_per_group;
132 /** Number of slices minus number of redundant slices. */
133 uint8_t data_slices_per_group;
134 /** Whether the header must be sent periodically. */
135 bool need_periodic_header;
136 /**
137 * Transport-layer initialisation for FEC support.
138 *
139 * This optional function serves (a) to make the transport layer
140 * ready to send FEC slices and (b) to determine the Maximum
141 * Packet Size (MPS) supported by the connection. The MPS value
142 * determines the largest payload size. This value is used to
143 * send FEC slices that are not larger than the path MTU, to avoid
144 * fragmentation and to maximize packet utilization. The user can
145 * alternatively specify a slice size of up to this value.
146 */
147 int (*init_fec)(struct sender_client *sc);
148 /** Push out FEC-encoded packets */
149 int (*send_fec)(struct sender_client *sc, char *buf, size_t len);
150 };
151
152 /** Describes the current status of one paraslash sender. */
153 struct sender_status {
154 /** The file descriptor of the socket this sender is listening on. */
155 int listen_fd;
156 /** The TCP/DCCP port used by this sender. */
157 int port;
158 /** The current number of simultaneous connections. */
159 int num_clients;
160 /** The maximal number of simultaneous connections. */
161 int max_clients;
162 /** Whether the access control list is a whitelist. */
163 int default_deny;
164 /** The whitelist/blacklist. */
165 struct list_head acl;
166 /** The list of connected clients. */
167 struct list_head client_list;
168 };
169
170 void shutdown_client(struct sender_client *sc, struct sender_status *ss);
171 void shutdown_clients(struct sender_status *ss);
172 void init_sender_status(struct sender_status *ss, char **access_arg, int num_access_args,
173 int port, int max_clients, int default_deny);
174 char *get_sender_info(struct sender_status *ss, const char *name);
175
176 void generic_com_allow(struct sender_command_data *scd,
177 struct sender_status *ss);
178 void generic_com_deny(struct sender_command_data *scd,
179 struct sender_status *ss);
180 int generic_com_on(struct sender_status *ss, unsigned protocol);
181 void generic_com_off(struct sender_status *ss);
182 char *generic_sender_help(void);
183 struct sender_client *accept_sender_client(struct sender_status *ss, fd_set *rfds);
184 int send_queued_chunks(int fd, struct chunk_queue *cq);
185 int parse_fec_url(const char *arg, struct sender_command_data *scd);