lssdp

light weight SSDP library

What is SSDP

The Simple Service Discovery Protocol (SSDP) is a network protocol based on the Internet Protocol Suite for advertisement and discovery of network services and presence information.

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Support Platform

• Linux Ubuntu
• MAC OSX
• Android
• iOS

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How To Build and Test

make clean
make

cd test
./daemon.exe

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lssdp_ctx:

lssdp context

port - SSDP UDP port, 1900 port is general.

sock - SSDP socket, created by lssdp_socket_create, and close by lssdp_socket_close

neighbor_list - neighbor list, when received NOTIFY or RESPONSE packet, neighbor list will be updated.

neighbor_timeout - this value will be used by lssdp_neighbor_check_timeout. If neighbor is timeout, then remove from neighbor list.

debug - SSDP debug mode, show debug message.

interface - Network Interface list. Call lssdp_network_interface_update to update the list.

interface_num - the number of Network Interface list.

header.search_target - SSDP Search Target (ST). A potential search target.

header.unique_service_name - SSDP Unique Service Name (USN). A composite identifier for the advertisement.

header.location = prefix + domain + suffix - [http://] + IP + [:PORT/URI]

header.sm_id - Optional field.

header.device_type - Optional field.

network_interface_changed_callback - when interface is changed, this callback would be invoked.

neighbor_list_changed_callback - when neighbor list is changed, this callback would be invoked.

packet_received_callback - when received any SSDP packet, this callback would be invoked. It callback is usally used for debugging.

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Function API (8)

01. lssdp_network_interface_update

update network interface.

- lssdp.interface, lssdp.interface_num will be updated.

02. lssdp_socket_create

create SSDP socket.

- SSDP port must be setup ready before call this function. (lssdp.port > 0)

- if SSDP socket is already exist (lssdp.sock > 0), the socket will be closed, and create a new one.

- SSDP neighbor list will be force clean up.

03. lssdp_socket_close

close SSDP socket.

- if SSDP socket <= 0, will be ignore, and lssdp.sock will be set -1.
- SSDP neighbor list will be force clean up.

04. lssdp_socket_read

read SSDP socket.

1. if read success, packet_received_callback will be invoked.

2. if received SSDP packet is match to Search Target (lssdp.header.search_target),
   - M-SEARCH: send RESPONSE back
   - NOTIFY/RESPONSE: add/update to SSDP neighbor list

- SSDP socket and port must be setup ready before call this function. (sock, port > 0)
- if SSDP neighbor list has been changed, neighbor_list_changed_callback will be invoked.

05. lssdp_send_msearch

send SSDP M-SEARCH packet to multicast address (239.255.255.250)

- SSDP port must be setup ready before call this function. (lssdp.port > 0)

06. lssdp_send_notify

send SSDP NOTIFY packet to multicast address (239.255.255.250)

- SSDP port must be setup ready before call this function. (lssdp.port > 0)

07. lssdp_neighbor_check_timeout

check neighbor in list is timeout or not. (lssdp.neighbor_timeout)

the timeout neighbor will be remove from the list.

- if neighbor be removed, neighbor_list_changed_callback will be invoked.

08. lssdp_set_log_callback

setup SSDP log callback. All SSDP library log will be forward to here.