libosmo-netif 1.5.1.5-89a1
Osmocom network interface library
Osmocom Stream Server

This code is intended to abstract any server-side use of stream-type sockets, such as TCP and SCTP. More...

Typedefs

typedef int(* osmo_stream_srv_link_accept_cb_t) (struct osmo_stream_srv_link *link, int fd)
 
typedef int(* osmo_stream_srv_read_cb_t) (struct osmo_stream_srv *conn)
 
typedef int(* osmo_stream_srv_closed_cb_t) (struct osmo_stream_srv *conn)
 
typedef int(* osmo_stream_srv_read_cb2_t) (struct osmo_stream_srv *conn, int res, struct msgb *msg)
 Completion call-back function when something was read from from the stream client socket. More...
 
typedef int(* osmo_stream_srv_segmentation_cb_t) (struct msgb *msg)
 

Enumerations

enum  osmo_stream_srv_link_param { OSMO_STREAM_SRV_LINK_PAR_SCTP_SOCKOPT_AUTH_SUPPORTED , OSMO_STREAM_SRV_LINK_PAR_SCTP_SOCKOPT_ASCONF_SUPPORTED , OSMO_STREAM_SRV_LINK_PAR_SCTP_INIT_NUM_OSTREAMS , OSMO_STREAM_SRV_LINK_PAR_SCTP_INIT_MAX_INSTREAMS }
 

Functions

struct osmo_stream_srv_link * osmo_stream_srv_link_create (void *ctx)
 Create an Osmocom Stream Server Link. More...
 
void osmo_stream_srv_link_destroy (struct osmo_stream_srv_link *link)
 Destroy the stream server link. More...
 
void osmo_stream_srv_link_set_name (struct osmo_stream_srv_link *link, const char *name)
 Set a name on the srv_link object (used during logging). More...
 
const char * osmo_stream_srv_link_get_name (const struct osmo_stream_srv_link *link)
 Retrieve name previously set on the srv_link object (see osmo_stream_srv_link_set_name()). More...
 
void osmo_stream_srv_link_set_nodelay (struct osmo_stream_srv_link *link, bool nodelay)
 Set the NODELAY socket option to avoid Nagle-like behavior. More...
 
void osmo_stream_srv_link_set_addr (struct osmo_stream_srv_link *link, const char *addr)
 Set the local address to which we bind. More...
 
int osmo_stream_srv_link_set_addrs (struct osmo_stream_srv_link *link, const char **addr, size_t addrcnt)
 Set the local address set to which we bind. More...
 
void osmo_stream_srv_link_set_port (struct osmo_stream_srv_link *link, uint16_t port)
 Set the local port number to which we bind. More...
 
void osmo_stream_srv_link_set_proto (struct osmo_stream_srv_link *link, uint16_t proto)
 Set the protocol for the stream server link. More...
 
int osmo_stream_srv_link_set_type (struct osmo_stream_srv_link *link, int type)
 Set the socket type for the stream server link. More...
 
int osmo_stream_srv_link_set_domain (struct osmo_stream_srv_link *link, int domain)
 Set the socket type for the stream server link. More...
 
void osmo_stream_srv_link_set_accept_cb (struct osmo_stream_srv_link *link, int(*accept_cb)(struct osmo_stream_srv_link *link, int fd))
 Set the accept() call-back of the stream server link. More...
 
void osmo_stream_srv_link_set_data (struct osmo_stream_srv_link *link, void *data)
 Set application private data of the stream server link. More...
 
void * osmo_stream_srv_link_get_data (struct osmo_stream_srv_link *link)
 Retrieve application private data of the stream server link. More...
 
char * osmo_stream_srv_link_get_sockname (const struct osmo_stream_srv_link *link)
 Retrieve description of the stream server link e. More...
 
struct osmo_fd * osmo_stream_srv_link_get_ofd (struct osmo_stream_srv_link *link)
 Retrieve Osmocom File Descriptor of the stream server link. More...
 
int osmo_stream_srv_link_get_fd (const struct osmo_stream_srv_link *link)
 Retrieve File Descriptor of the stream server link. More...
 
bool osmo_stream_srv_link_is_opened (const struct osmo_stream_srv_link *link)
 Check whether the stream server link is opened. More...
 
int osmo_stream_srv_link_open (struct osmo_stream_srv_link *link)
 Open the stream server link. More...
 
void osmo_stream_srv_link_close (struct osmo_stream_srv_link *link)
 Close the stream server link and unregister from select loop. More...
 
int osmo_stream_srv_link_set_param (struct osmo_stream_srv_link *link, enum osmo_stream_srv_link_param par, void *val, size_t val_len)
 Set given parameter of stream_srv_link to given value. More...
 
struct osmo_stream_srv * osmo_stream_srv_create (void *ctx, struct osmo_stream_srv_link *link, int fd, osmo_stream_srv_read_cb_t read_cb, osmo_stream_srv_closed_cb_t closed_cb, void *data)
 Create a legacy osmo_fd mode Stream Server inside the specified link. More...
 
struct osmo_stream_srv * osmo_stream_srv_create2 (void *ctx, struct osmo_stream_srv_link *link, int fd, void *data)
 Create an osmo_iofd mode Stream Server inside the specified link. More...
 
void osmo_stream_srv_set_name (struct osmo_stream_srv *conn, const char *name)
 Set a name on the srv object (used during logging). More...
 
const char * osmo_stream_srv_get_name (const struct osmo_stream_srv *conn)
 Retrieve name previously set on the srv object (see osmo_stream_srv_set_name()). More...
 
void osmo_stream_srv_set_read_cb (struct osmo_stream_srv *conn, osmo_stream_srv_read_cb2_t read_cb)
 Set the call-back function for incoming data on an osmo_io stream_srv. More...
 
void osmo_stream_srv_set_closed_cb (struct osmo_stream_srv *conn, osmo_stream_srv_closed_cb_t closed_cb)
 Set the call-back function called when the stream server socket was closed. More...
 
void * osmo_stream_srv_get_data (struct osmo_stream_srv *conn)
 Retrieve application private data of the stream server. More...
 
struct osmo_stream_srv_link * osmo_stream_srv_get_master (struct osmo_stream_srv *conn)
 Retrieve the master (Link) from a Stream Server. More...
 
const char * osmo_stream_srv_get_sockname (const struct osmo_stream_srv *conn)
 Retrieve the stream server socket description. More...
 
struct osmo_fd * osmo_stream_srv_get_ofd (struct osmo_stream_srv *conn)
 Retrieve Osmocom File Descriptor of a stream server in osmo_fd mode. More...
 
int osmo_stream_srv_get_fd (const struct osmo_stream_srv *conn)
 Retrieve File Descriptor of the stream server. More...
 
struct osmo_io_fd * osmo_stream_srv_get_iofd (const struct osmo_stream_srv *srv)
 Retrieve osmo_io descriptor of the stream server socket. More...
 
void osmo_stream_srv_destroy (struct osmo_stream_srv *conn)
 Destroy given Stream Server. More...
 
void osmo_stream_srv_set_flush_and_destroy (struct osmo_stream_srv *conn)
 Prepare to send out all pending messages on the connection's Tx queue. More...
 
void osmo_stream_srv_set_data (struct osmo_stream_srv *conn, void *data)
 Set application private data of the stream server. More...
 
void osmo_stream_srv_set_segmentation_cb (struct osmo_stream_srv *conn, osmo_stream_srv_segmentation_cb_t segmentation_cb)
 Set the segmentation callback for target osmo_stream_srv structure. More...
 
void osmo_stream_srv_send (struct osmo_stream_srv *conn, struct msgb *msg)
 Enqueue data to be sent via an Osmocom stream server. More...
 
int osmo_stream_srv_recv (struct osmo_stream_srv *conn, struct msgb *msg)
 Receive data via an Osmocom stream server in osmo_fd mode. More...
 
void osmo_stream_srv_clear_tx_queue (struct osmo_stream_srv *conn)
 

Detailed Description

This code is intended to abstract any server-side use of stream-type sockets, such as TCP and SCTP.

The Osmocom stream socket helper is an abstraction layer for connected SOCK_STREAM/SOCK_SEQPACKET sockets. It encapsulates common functionality like binding, accepting client connections, etc.

osmo_stream_srv can operate in two different modes:

  1. The legacy mode using osmo_fd (from libosmocore)
  2. The modern (2023) mode using osmo_io (from libosmocore)

For any new applications, you definitely should use the modern mode, as it provides you with a higher layer of abstraction and allows you to perform efficient I/O using the io_uring backend of osmo_io.

The two main objects are osmo_stream_srv_link (main server accept()ing incoming connections) and osmo_stream_srv (a single given connection from a remote client).

A typical stream_srv usage would look like this:

Whenever a client connects to your listening socket, the connection will now be automatically accept()ed and the registered accept_cb call-back called. From within that accept_cb, you then

Whenever data from a client arrives on a connection, your registered read_cb will be called together with a message buffer containing the received data. Ownership of the message buffer is transferred into the call-back, i.e. in your application. It's your responsibility to eventually msgb_free() it after usage.

Whenever your application wants to transmit something to a given connection, it uses the osmo_stream_srv_send() function.

Typedef Documentation

◆ osmo_stream_srv_read_cb2_t

typedef int(* osmo_stream_srv_read_cb2_t) (struct osmo_stream_srv *conn, int res, struct msgb *msg)

Completion call-back function when something was read from from the stream client socket.

Parameters
[in]connStream Server that got receive event.
[in]resreturn value of the read()/recvmsg()/... call, or -errno in case of error.
[in]msgmessage buffer containing the read data. Ownership is transferred to the call-back, and it must make sure to msgb_free() it eventually!

Function Documentation

◆ osmo_stream_srv_create()

struct osmo_stream_srv * osmo_stream_srv_create ( void *  ctx,
struct osmo_stream_srv_link *  link,
int  fd,
osmo_stream_srv_read_cb_t  read_cb,
osmo_stream_srv_closed_cb_t  closed_cb,
void *  data 
)

Create a legacy osmo_fd mode Stream Server inside the specified link.

This is the function an application traditionally calls from within the accept_cb call-back of the osmo_stream_srv_link. It creates a new osmo_stream_srv within that link.

New users/programs should use osmo_stream_srv_create2 to operate in osmo_io mode instead.

Parameters
[in]ctxtalloc allocation context from which to allocate
[in]linkStream Server Link to which we belong
[in]fdsystem file descriptor of the new connection
[in]read_cbCall-back to call when the socket is readable
[in]closed_cbCall-back to call when the connection is closed
[in]dataUser data to save in the new Stream Server struct
Returns
Stream Server in case of success; NULL on error

◆ osmo_stream_srv_create2()

struct osmo_stream_srv * osmo_stream_srv_create2 ( void *  ctx,
struct osmo_stream_srv_link *  link,
int  fd,
void *  data 
)

Create an osmo_iofd mode Stream Server inside the specified link.

This is the function an application typically calls from within the accept_cb call-back of the osmo_stream_srv_link. It creates a new osmo_stream_srv in osmo_io mode within that link.

Parameters
[in]ctxtalloc allocation context from which to allocate
[in]linkStream Server Link to which we belong
[in]fdsystem file descriptor of the new connection
[in]dataUser data to save in the new Stream Server struct
Returns
Stream Server in case of success; NULL on error

◆ osmo_stream_srv_destroy()

void osmo_stream_srv_destroy ( struct osmo_stream_srv *  conn)

Destroy given Stream Server.

This function closes the Stream Server socket, unregisters from the underlying I/O mechanism, invokes the connection's closed_cb() callback to allow API users to clean up any associated state they have for this connection, and then de-allocates associated memory.

Parameters
[in]connStream Server to be destroyed

◆ osmo_stream_srv_get_data()

void * osmo_stream_srv_get_data ( struct osmo_stream_srv *  conn)

Retrieve application private data of the stream server.

Parameters
[in]connStream Server
Returns
Application private data, as set by osmo_stream_srv_set_data()

◆ osmo_stream_srv_get_fd()

int osmo_stream_srv_get_fd ( const struct osmo_stream_srv *  conn)

Retrieve File Descriptor of the stream server.

Parameters
[in]connStream Server
Returns
file descriptor or negative on error

Referenced by osmo_stream_srv_get_sockname().

◆ osmo_stream_srv_get_iofd()

struct osmo_io_fd * osmo_stream_srv_get_iofd ( const struct osmo_stream_srv *  srv)

Retrieve osmo_io descriptor of the stream server socket.

This function must not be called on a stream server in legacy osmo_fd mode!

Parameters
[in]srvStream Server of which we want to obtain the osmo_io descriptor
Returns
osmo_io_fd of stream server.

◆ osmo_stream_srv_get_master()

struct osmo_stream_srv_link * osmo_stream_srv_get_master ( struct osmo_stream_srv *  conn)

Retrieve the master (Link) from a Stream Server.

Parameters
[in]connStream Server of which we want to know the Link
Returns
Link through which the given Stream Server is established

◆ osmo_stream_srv_get_name()

const char * osmo_stream_srv_get_name ( const struct osmo_stream_srv *  conn)

Retrieve name previously set on the srv object (see osmo_stream_srv_set_name()).

Parameters
[in]connserver whose name is to be retrieved
Returns
The name to be set on conn; NULL if never set

◆ osmo_stream_srv_get_ofd()

struct osmo_fd * osmo_stream_srv_get_ofd ( struct osmo_stream_srv *  conn)

Retrieve Osmocom File Descriptor of a stream server in osmo_fd mode.

Parameters
[in]connStream Server
Returns
Pointer to osmo_fd

◆ osmo_stream_srv_get_sockname()

const char * osmo_stream_srv_get_sockname ( const struct osmo_stream_srv *  conn)

Retrieve the stream server socket description.

The returned name is stored in a static buffer; it is hence not re-entrant or thread-safe!

Parameters
[in]cliStream Server to examine
Returns
Socket description or NULL in case of error

References osmo_stream_srv_get_fd().

◆ osmo_stream_srv_link_close()

void osmo_stream_srv_link_close ( struct osmo_stream_srv_link *  link)

Close the stream server link and unregister from select loop.

Does not destroy the server link, merely closes it!

Parameters
[in]linkStream Server Link to close

References osmo_stream_srv_link_is_opened().

Referenced by osmo_stream_srv_link_destroy().

◆ osmo_stream_srv_link_create()

struct osmo_stream_srv_link * osmo_stream_srv_link_create ( void *  ctx)

Create an Osmocom Stream Server Link.

A Stream Server Link is the listen()+accept() "parent" to individual connections from remote clients.

Parameters
[in]ctxtalloc allocation context
Returns
Stream Server Link with default values (AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP)

◆ osmo_stream_srv_link_destroy()

void osmo_stream_srv_link_destroy ( struct osmo_stream_srv_link *  link)

Destroy the stream server link.

Closes + Releases Memory.

Parameters
[in]linkStream Server Link

References osmo_stream_srv_link_close().

◆ osmo_stream_srv_link_get_data()

void * osmo_stream_srv_link_get_data ( struct osmo_stream_srv_link *  link)

Retrieve application private data of the stream server link.

Parameters
[in]linkStream Server Link to modify
Returns
Application private data, as set by osmo_stream_cli_set_data()

◆ osmo_stream_srv_link_get_fd()

int osmo_stream_srv_link_get_fd ( const struct osmo_stream_srv_link *  link)

Retrieve File Descriptor of the stream server link.

Parameters
[in]connStream Server Link
Returns
file descriptor or negative on error

◆ osmo_stream_srv_link_get_name()

const char * osmo_stream_srv_link_get_name ( const struct osmo_stream_srv_link *  link)

Retrieve name previously set on the srv_link object (see osmo_stream_srv_link_set_name()).

Parameters
[in]linkserver link whose name is to be retrieved
Returns
The name to be set on link; NULL if never set

◆ osmo_stream_srv_link_get_ofd()

struct osmo_fd * osmo_stream_srv_link_get_ofd ( struct osmo_stream_srv_link *  link)

Retrieve Osmocom File Descriptor of the stream server link.

Parameters
[in]linkStream Server Link
Returns
Pointer to osmo_fd

◆ osmo_stream_srv_link_get_sockname()

char * osmo_stream_srv_link_get_sockname ( const struct osmo_stream_srv_link *  link)

Retrieve description of the stream server link e.

g. 127.0.0.1:1234. Calling this function will build a string that describes the socket in terms of its local/remote address/port. The returned name is stored in a static buffer; it is hence not re-entrant or thread-safe.

Parameters
[in]linkStream Server Link to examine
Returns
Link description or NULL in case of error

◆ osmo_stream_srv_link_is_opened()

bool osmo_stream_srv_link_is_opened ( const struct osmo_stream_srv_link *  link)

Check whether the stream server link is opened.

Parameters
[in]linkStream Server Link to check

Referenced by osmo_stream_srv_link_close().

◆ osmo_stream_srv_link_open()

int osmo_stream_srv_link_open ( struct osmo_stream_srv_link *  link)

Open the stream server link.

This actually initializes the underlying socket and binds it to the configured ip/port.

Parameters
[in]linkStream Server Link to open
Returns
negative on error, 0 on success

◆ osmo_stream_srv_link_set_accept_cb()

void osmo_stream_srv_link_set_accept_cb ( struct osmo_stream_srv_link *  link,
int(*)(struct osmo_stream_srv_link *link, int fd)  accept_cb 
)

Set the accept() call-back of the stream server link.

The provided call-back will be called whenever a new inbound connection is accept()ed. The call-back then typically creates a new osmo_stream_srv. If the call-back returns a negative value, the file descriptor will be closed.

Parameters
[in]linkStream Server Link
[in]accept_cbCall-back function executed upon accept()

◆ osmo_stream_srv_link_set_addr()

void osmo_stream_srv_link_set_addr ( struct osmo_stream_srv_link *  link,
const char *  addr 
)

Set the local address to which we bind.

Any changes to this setting will only become active upon next (re)connect.

Parameters
[in]linkStream Server Link to modify
[in]addrLocal IP address

References osmo_stream_srv_link_set_addrs().

◆ osmo_stream_srv_link_set_addrs()

int osmo_stream_srv_link_set_addrs ( struct osmo_stream_srv_link *  link,
const char **  addr,
size_t  addrcnt 
)

Set the local address set to which we bind.

Useful for protocols allowing bind on more than one address (such as SCTP) Any changes to this setting will only become active upon next (re)connect.

Parameters
[in]linkStream Server Link to modify
[in]addrLocal IP address
Returns
negative on error, 0 on success

Referenced by osmo_stream_srv_link_set_addr().

◆ osmo_stream_srv_link_set_data()

void osmo_stream_srv_link_set_data ( struct osmo_stream_srv_link *  link,
void *  data 
)

Set application private data of the stream server link.

Parameters
[in]linkStream Server Link to modify
[in]dataUser-specific data (available in call-back functions)

◆ osmo_stream_srv_link_set_domain()

int osmo_stream_srv_link_set_domain ( struct osmo_stream_srv_link *  link,
int  domain 
)

Set the socket type for the stream server link.

Any changes to this setting will only become active upon next (re)connect.

Parameters
[in]linkStream Server Link to modify
[in]typeSocket Domain (like AF_UNSPEC (default for IP), AF_UNIX, AF_INET, ...)
Returns
zero on success, negative on error.

◆ osmo_stream_srv_link_set_name()

void osmo_stream_srv_link_set_name ( struct osmo_stream_srv_link *  link,
const char *  name 
)

Set a name on the srv_link object (used during logging).

Parameters
[in]linkserver link whose name is to be set. The name is copied into the osmo_stream_srv_link, so the caller memory is not required to be valid beyond the call of this function.
[in]namethe name to be set on link

◆ osmo_stream_srv_link_set_nodelay()

void osmo_stream_srv_link_set_nodelay ( struct osmo_stream_srv_link *  link,
bool  nodelay 
)

Set the NODELAY socket option to avoid Nagle-like behavior.

Setting this to nodelay=true will automatically set the NODELAY socket option on any socket established via this server link, before calling the accept_cb()

Parameters
[in]linkserver link whose sockets are to be configured
[in]nodelaywhether to set (true) NODELAY after accept

◆ osmo_stream_srv_link_set_param()

int osmo_stream_srv_link_set_param ( struct osmo_stream_srv_link *  link,
enum osmo_stream_srv_link_param  par,
void *  val,
size_t  val_len 
)

Set given parameter of stream_srv_link to given value.

Parameters
[in]clistream client on which to set parameter.
[in]paridentifier of the parameter to be set.
[in]valvalue of the parameter to be set.
[in]val_lenlength of the parameter value.
Returns
0 in success; negative -errno on error.

◆ osmo_stream_srv_link_set_port()

void osmo_stream_srv_link_set_port ( struct osmo_stream_srv_link *  link,
uint16_t  port 
)

Set the local port number to which we bind.

Any changes to this setting will only become active upon next (re)connect.

Parameters
[in]linkStream Server Link to modify
[in]portLocal port number

◆ osmo_stream_srv_link_set_proto()

void osmo_stream_srv_link_set_proto ( struct osmo_stream_srv_link *  link,
uint16_t  proto 
)

Set the protocol for the stream server link.

Any changes to this setting will only become active upon next (re)connect.

Parameters
[in]linkStream Server Link to modify
[in]protoProtocol (like IPPROTO_TCP (default), IPPROTO_SCTP, ...)

◆ osmo_stream_srv_link_set_type()

int osmo_stream_srv_link_set_type ( struct osmo_stream_srv_link *  link,
int  type 
)

Set the socket type for the stream server link.

Any changes to this setting will only become active upon next (re)connect.

Parameters
[in]linkStream Server Link to modify
[in]typeSocket Type (like SOCK_STREAM (default), SOCK_SEQPACKET, ...)
Returns
zero on success, negative on error.

◆ osmo_stream_srv_recv()

int osmo_stream_srv_recv ( struct osmo_stream_srv *  conn,
struct msgb *  msg 
)

Receive data via an Osmocom stream server in osmo_fd mode.

Parameters
[in]connStream Server from which to receive
msgpre-allocate message buffer to which received data is appended
Returns
number of bytes read, negative on error.

Application programs using the legacy osmo_fd mode of osmo_stream_srv will use this function to read/receive from a stream socket after they have been notified that it is readable (via select/poll).

If conn is an SCTP connection, additional specific considerations shall be taken:

  • msg->cb is always filled with SCTP ppid, and SCTP stream values, see msgb_sctp_*() APIs.
  • If an SCTP notification was received when reading from the SCTP socket, msgb_sctp_msg_flags(msg) will contain bit flag OSMO_STREAM_SCTP_MSG_FLAGS_NOTIFICATION set, and the msgb will contain a "union sctp_notification" instead of user data. In this case the return code will be either 0 (if conn is considered dead after the notification) or -EAGAIN (if conn is considered still alive after the notification) resembling the standard recv() API.

◆ osmo_stream_srv_send()

void osmo_stream_srv_send ( struct osmo_stream_srv *  conn,
struct msgb *  msg 
)

Enqueue data to be sent via an Osmocom stream server.

Parameters
[in]connStream Server through which we want to send
[in]msgMessage buffer to enqueue in transmit queue

◆ osmo_stream_srv_set_closed_cb()

void osmo_stream_srv_set_closed_cb ( struct osmo_stream_srv *  conn,
osmo_stream_srv_closed_cb_t  closed_cb 
)

Set the call-back function called when the stream server socket was closed.

Whenever the socket was closed (network error, client disconnect, etc.), the user-provided call-back function given here is called. This is typically used by the application to clean up any of its internal state related to this specific client/connection.

Parameters
[in]connStream Server to modify
[in]closed_cbCall-back function to be called when the connection was closed

◆ osmo_stream_srv_set_data()

void osmo_stream_srv_set_data ( struct osmo_stream_srv *  conn,
void *  data 
)

Set application private data of the stream server.

Parameters
[in]connStream Server to modify
[in]dataUser-specific data (available in call-back functions)

◆ osmo_stream_srv_set_flush_and_destroy()

void osmo_stream_srv_set_flush_and_destroy ( struct osmo_stream_srv *  conn)

Prepare to send out all pending messages on the connection's Tx queue.

and then automatically destroy the stream with osmo_stream_srv_destroy(). This function disables queuing of new messages on the connection and also disables reception of new messages on the connection.

Parameters
[in]connStream Server to modify

◆ osmo_stream_srv_set_name()

void osmo_stream_srv_set_name ( struct osmo_stream_srv *  conn,
const char *  name 
)

Set a name on the srv object (used during logging).

Parameters
[in]connserver whose name is to be set. The name is copied into the osmo_stream_srv_link, so the caller memory is not required to be valid beyond the call of this function.
[in]namethe name to be set on conn

◆ osmo_stream_srv_set_read_cb()

void osmo_stream_srv_set_read_cb ( struct osmo_stream_srv *  conn,
osmo_stream_srv_read_cb2_t  read_cb 
)

Set the call-back function for incoming data on an osmo_io stream_srv.

This function only works with osmo_stream_srv in osmo_io mode, created by osmo_stream_srv_create2()!

Whenever data is received on the osmo_stram_srv, the read_cb call-back function of the user application is called.

Parameters
[in]connStream Server to modify
[in]read_cbCall-back function to be called when data was read

◆ osmo_stream_srv_set_segmentation_cb()

void osmo_stream_srv_set_segmentation_cb ( struct osmo_stream_srv *  conn,
osmo_stream_srv_segmentation_cb_t  segmentation_cb 
)

Set the segmentation callback for target osmo_stream_srv structure.

A segmentation call-back can optionally be used when a packet based protocol (like TCP) is used within a STREAM style socket that does not preserve message boundaries within the stream. If a segmentation call-back is given, the osmo_stream_srv library code will makes sure that the read_cb called only for complete single messages, and not arbitrary segments of the stream.

This function only works with osmo_stream_srv in osmo_io mode, created by osmo_stream_srv_create2()! The connection has to have been established prior to calling this function.

Parameters
[in,out]connTarget Stream Server to modify
[in]segmentation_cbSegmentation callback to be set