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         /** Dellocate all resources. Only called on exit. */
  89         void (*shutdown)(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 /** NULL-terminated list, defined in \ref vss.c. */
 110 extern const struct sender * const senders[];
 111 /** Iterate over all senders. */
 112 #define FOR_EACH_SENDER(_i) for ((_i) = 0; senders[(_i)]; (_i)++)
 113
 114 /** Describes one client, connected to a paraslash sender. */
 115 struct sender_client {
 116         /** The file descriptor of the client. */
 117         int fd;
 118         /** The socket "name" of the client. */
 119         char *name;
 120         /** The position of this client in the client list. */
 121         struct list_head node;
 122         /** Non-zero if audio file header has been sent. */
 123         int header_sent;
 124         /** The list of pending chunks for this client. */
 125         struct chunk_queue *cq;
 126         /** Data specific to the particular sender. */
 127         void *private_data;
 128 };
 129
 130 /**
 131  * Each paraslash sender may register arbitrary many clients to the virtual
 132  * streaming system, possibly with varying fec parameters. In order to do so,
 133  * it must allocate a \a fec_client_parms structure and pass it to \ref
 134  * vss_add_fec_client.
 135  *
 136  * Clients are automatically removed from that list by the vss if an error
 137  * occurs, or if the sender requests deletion of a client by calling \ref
 138  * vss_del_fec_client().
 139  */
 140
 141 /** FEC parameters requested by FEC clients. */
 142 struct fec_client_parms {
 143         /** Number of data slices plus redundant slices. */
 144         uint8_t slices_per_group;
 145         /** Number of slices minus number of redundant slices. */
 146         uint8_t data_slices_per_group;
 147         /** Whether the header must be sent periodically. */
 148         bool need_periodic_header;
 149         /**
 150          * Transport-layer initialisation for FEC support.
 151          *
 152          * This optional function serves (a) to make the transport layer
 153          * ready to send FEC slices and (b) to determine the Maximum
 154          * Packet Size (MPS) supported by the connection. The MPS value
 155          * determines the largest payload size. This value is used to
 156          * send FEC slices that are not larger than the path MTU, to avoid
 157          * fragmentation and to maximize packet utilization. The user can
 158          * alternatively specify a slice size of up to this value.
 159          */
 160         int (*init_fec)(struct sender_client *sc);
 161         /** Push out FEC-encoded packets */
 162         void (*send_fec)(struct sender_client *sc, char *buf, size_t len);
 163 };
 164
 165 /** Describes the current status of one paraslash sender. */
 166 struct sender_status {
 167         /** The file descriptor of the socket this sender is listening on. */
 168         int listen_fd;
 169         /** The TCP/DCCP port used by this sender. */
 170         int port;
 171         /** The current number of simultaneous connections. */
 172         int num_clients;
 173         /** The maximal number of simultaneous connections. */
 174         int max_clients;
 175         /** Whether the access control list is a whitelist. */
 176         int default_deny;
 177         /** The whitelist/blacklist. */
 178         struct list_head acl;
 179         /** The list of connected clients. */
 180         struct list_head client_list;
 181 };
 182
 183 void shutdown_client(struct sender_client *sc, struct sender_status *ss);
 184 void shutdown_clients(struct sender_status *ss);
 185 void init_sender_status(struct sender_status *ss,
 186                 const struct lls_opt_result *acl_opt_result, int port,
 187                 int max_clients, int default_deny);
 188 char *generic_sender_status(struct sender_status *ss, const char *name);
 189 void generic_com_allow(struct sender_command_data *scd,
 190                 struct sender_status *ss);
 191 void generic_com_deny(struct sender_command_data *scd,
 192                 struct sender_status *ss);
 193 void generic_com_on(struct sender_status *ss, unsigned protocol);
 194 void generic_acl_deplete(struct list_head *acl);
 195 void generic_com_off(struct sender_status *ss);
 196 char *generic_sender_help(void);
 197 struct sender_client *accept_sender_client(struct sender_status *ss, fd_set *rfds);
 198 int send_queued_chunks(int fd, struct chunk_queue *cq);
 199 int parse_fec_url(const char *arg, struct sender_command_data *scd);