server: Make array of senders constant.
[paraslash.git] / send.h
1 /* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
2
3 /** \file send.h Sender-related defines and structures. */
4
5 #define SENDER_SUBCOMMANDS \
6 SENDER_SUBCOMMAND(add) /**< Add a target (udp only). */ \
7 SENDER_SUBCOMMAND(delete) /**< Delete a target (udp only). */ \
8 SENDER_SUBCOMMAND(allow) /**< Allow connections from given IP address(es). */ \
9 SENDER_SUBCOMMAND(deny) /**< Deny connections from given IP address(es). */ \
10 SENDER_SUBCOMMAND(on) /**< Activate the sender. */ \
11 SENDER_SUBCOMMAND(off) /**< Deactivate the sender. */ \
12
13 #define SENDER_SUBCOMMAND(_name) SENDER_ ## _name,
14 enum sender_subcommand {
15 SENDER_SUBCOMMANDS
16 NUM_SENDER_CMDS /**< Used as array size in struct \ref sender. */
17 };
18 #undef SENDER_SUBCOMMAND
19 #define SENDER_SUBCOMMAND(_name) #_name,
20
21 /**
22 * Describes one supported sender of para_server.
23 *
24 * \sa \ref http_send.c \ref udp_send.c, \ref dccp_send.c.
25 */
26 struct sender {
27 /** The name of the sender. */
28 const char *name;
29 /**
30 * Parse the command line options and initialize this sender (e.g.,
31 * initialize target or access control lists, listen on a network
32 * socket, etc.).
33 */
34 void (*init)(void);
35 /**
36 * Return the help text of this sender.
37 *
38 * The result must be dynamically allocated and is freed by the caller.
39 */
40 char* (*help)(void);
41 /**
42 * Return current status info about this sender.
43 *
44 * The result must be dynamically allocated and is freed by the caller.
45 */
46 char* (*status)(void);
47 /**
48 * The send-hook.
49 *
50 * It gets called whenever para_server is playing and the current
51 * audio format handler indicates that another chunk of data should
52 * be sent now. The two parameters \a current_chunk and \a chunks_sent
53 * only differ if the stream was repositioned by the \a ff or \a jmp
54 * command. Of course, \a buf is a pointer to the chunk of data which
55 * should be sent, and \a len is the length of this buffer.
56 */
57 void (*send)(long unsigned current_chunk, long unsigned chunks_sent,
58 const char *buf, size_t len, const char *header_buf,
59 size_t header_len);
60 /**
61 * Add file descriptors to fd_sets.
62 *
63 * The pre_select function of each supported sender is called just before
64 * para_server enters its main select loop. Each sender may add its own
65 * file descriptors to the \a rfds or the \a wfds set.
66 *
67 * If a file descriptor was added, \a max_fileno must be increased by
68 * this function, if necessary.
69 *
70 * \sa select(2).
71 */
72 void (*pre_select)(int *max_fileno, fd_set *rfds, fd_set *wfds);
73 /**
74 * Handle the file descriptors which are ready for I/O.
75 *
76 * If the pre_select hook added one ore more file descriptors to the
77 * read or write set, this is the hook to check the result and do any
78 * I/O on those descriptors which are ready for reading/writing.
79 */
80 void (*post_select)(fd_set *rfds, fd_set *wfds);
81 /**
82 * Terminate all connected clients.
83 *
84 * This is called e.g. if the stop command was executed. It should make
85 * the clients aware of the end-of-file condition.
86 */
87 void (*shutdown_clients)(void);
88 /**
89 * Array of function pointers for the sender subcommands.
90 *
91 * Each sender may implement any subset of the sender commands by
92 * filling in the appropriate function pointer in the array. A \p NULL
93 * pointer means this command is not implemented by this sender.
94 */
95 int (*client_cmds[NUM_SENDER_CMDS])(struct sender_command_data*);
96 /**
97 * Resolve target-specific URL string
98 *
99 * This method must be defined if the sender supports the add/delete
100 * subcommands. It interprets a string specifying a target URL in a
101 * sender-specific fashion (e.g. embedded FEC string). It can also
102 * fill in sender-specific defaults if necessary.
103 */
104 int (*resolve_target)(const char *, struct sender_command_data *);
105 };
106
107 /** NULL-terminated list, defined in \ref vss.c. */
108 extern const struct sender * const senders[];
109 /** Iterate over all senders. */
110 #define FOR_EACH_SENDER(_i) for ((_i) = 0; senders[(_i)]; (_i)++)
111
112 /** Describes one client, connected to a paraslash sender. */
113 struct sender_client {
114 /** The file descriptor of the client. */
115 int fd;
116 /** The socket "name" of the client. */
117 char *name;
118 /** The position of this client in the client list. */
119 struct list_head node;
120 /** Non-zero if audio file header has been sent. */
121 int header_sent;
122 /** The list of pending chunks for this client. */
123 struct chunk_queue *cq;
124 /** Data specific to the particular sender. */
125 void *private_data;
126 };
127
128 /**
129 * Each paraslash sender may register arbitrary many clients to the virtual
130 * streaming system, possibly with varying fec parameters. In order to do so,
131 * it must allocate a \a fec_client_parms structure and pass it to \ref
132 * vss_add_fec_client.
133 *
134 * Clients are automatically removed from that list by the vss if an error
135 * occurs, or if the sender requests deletion of a client by calling \ref
136 * vss_del_fec_client().
137 */
138
139 /** FEC parameters requested by FEC clients. */
140 struct fec_client_parms {
141 /** Number of data slices plus redundant slices. */
142 uint8_t slices_per_group;
143 /** Number of slices minus number of redundant slices. */
144 uint8_t data_slices_per_group;
145 /** Whether the header must be sent periodically. */
146 bool need_periodic_header;
147 /**
148 * Transport-layer initialisation for FEC support.
149 *
150 * This optional function serves (a) to make the transport layer
151 * ready to send FEC slices and (b) to determine the Maximum
152 * Packet Size (MPS) supported by the connection. The MPS value
153 * determines the largest payload size. This value is used to
154 * send FEC slices that are not larger than the path MTU, to avoid
155 * fragmentation and to maximize packet utilization. The user can
156 * alternatively specify a slice size of up to this value.
157 */
158 int (*init_fec)(struct sender_client *sc);
159 /** Push out FEC-encoded packets */
160 void (*send_fec)(struct sender_client *sc, char *buf, size_t len);
161 };
162
163 /** Describes the current status of one paraslash sender. */
164 struct sender_status {
165 /** The file descriptor of the socket this sender is listening on. */
166 int listen_fd;
167 /** The TCP/DCCP port used by this sender. */
168 int port;
169 /** The current number of simultaneous connections. */
170 int num_clients;
171 /** The maximal number of simultaneous connections. */
172 int max_clients;
173 /** Whether the access control list is a whitelist. */
174 int default_deny;
175 /** The whitelist/blacklist. */
176 struct list_head acl;
177 /** The list of connected clients. */
178 struct list_head client_list;
179 };
180
181 void shutdown_client(struct sender_client *sc, struct sender_status *ss);
182 void shutdown_clients(struct sender_status *ss);
183 void init_sender_status(struct sender_status *ss,
184 const struct lls_opt_result *acl_opt_result, int port,
185 int max_clients, int default_deny);
186 char *generic_sender_status(struct sender_status *ss, const char *name);
187 void generic_com_allow(struct sender_command_data *scd,
188 struct sender_status *ss);
189 void generic_com_deny(struct sender_command_data *scd,
190 struct sender_status *ss);
191 int generic_com_on(struct sender_status *ss, unsigned protocol);
192 void generic_com_off(struct sender_status *ss);
193 char *generic_sender_help(void);
194 struct sender_client *accept_sender_client(struct sender_status *ss, fd_set *rfds);
195 int send_queued_chunks(int fd, struct chunk_queue *cq);
196 int parse_fec_url(const char *arg, struct sender_command_data *scd);