设备搜索：要访问一个IPC摄像头，或者说要调用IPC摄像头提供的WEB服务接口，就要先知道其IP地址，这就是设备发现的过程，或者叫设备搜索的过程。IPC摄像头用的是239.255.255.250（端口3702），所以设备搜索的原理是，只要在设备上服务器监听239.255.255.250的3702端口。ONVIF规范并没有自己定义服务设备发现框架，而是复用了已经很成熟的WS-Discovery标准，根据.wsdl的文件，用gsoap产生框架代码，调用其产生的函数接口去实现设备的搜索。
1、gsoap框架代码：https://blog.csdn.net/weixin_42432281/article/details/84818575
2、上一部如果完成，就直接略过，将安装的gsoap-2.8\gsoap目录下的两个文件：stdsoap2.c、stdsoap2.h拷贝到你工作目录下
3、注释stdsoap2.c如下代码：不注释的话会在编译运行的时候产生log日志，最后会发现磁盘已满的现象。
/*
#ifdef SOAP_DEBUG
#ifdef TANDEM_NONSTOP
soap_set_test_logfile(soap, "TESTLOG");
soap_set_sent_logfile(soap, "SENTLOG");
soap_set_recv_logfile(soap, "RECVLOG");
#else
soap_set_test_logfile(soap, "TEST.log");
soap_set_sent_logfile(soap, "SENT.log");
soap_set_recv_logfile(soap, "RECV.log");
#endif
#endif
*/
和修改
if (/*s == r || *r || */n < -128 || n > 127)
4、将安装的gsoap2.8目录下的import目录，拷贝到生成.c、.h的工作的文件夹里，cp gsoap-2.8/gsoap/import ./ ,REAMOD.txt是我写的记录文档，不必在意，其他的文件都拷贝到这个目录下
5、设备搜索的代码：我是直接copy别人的代码，做了一下修改（https://blog.csdn.net/saloon_yuan/article/details/27524875）
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "soapH.h"
#include "stdsoap2.h"
#include "soapStub.h"
#include "wsdd.nsmap" //命名空间
static struct soap* ONVIF_Initsoap(struct SOAP_ENV__Header *header, const char *was_To, const char *was_Action, int timeout)
{
struct soap *soap = NULL; // soap环境变量
unsigned char macaddr[6];
char _HwId[1024];
unsigned int Flagrand;
soap = soap_new();
if(soap == NULL)
{
printf("[%d]soap = NULL\n", __LINE__);
return NULL;
}
soap_set_namespaces(soap, namespaces); // 设置soap的namespaces，即设置命名空间
// 设置超时（超过指定时间没有数据就退出）
if(timeout > 0)
{
soap->recv_timeout = timeout;
soap->send_timeout = timeout;
soap->connect_timeout = timeout;
}
else
{
//Maximum waittime : 20s
soap->recv_timeout = 20;
soap->send_timeout = 20;
soap->connect_timeout = 20;
}
soap_default_SOAP_ENV__Header(soap, header);
//Create SessionID randomly,生成uuid(windows下叫guid，linux下叫uuid)，格式为urn:uuid:8-4-4-4-12，由系统随机产生
srand((int)time(0));
Flagrand = rand()%9000 + 8888;
macaddr[0] = 0x1;
macaddr[1] = 0x2;
macaddr[2] = 0x3;
macaddr[3] = 0x4;
macaddr[4] = 0x5;
macaddr[5] = 0x6;
sprintf(_HwId, "urn:uuid:%ud68a-1dd2-11b2-a105-%02X%02X%02X%02X%02X%02X", Flagrand, macaddr[0], macaddr[1], macaddr[2],macaddr[3],macaddr[4],macaddr[5]);
header->wsa__MessageID = (char *)malloc(100);
memset(header->wsa__MessageID, 0, 100);
strncpy(header->wsa__MessageID, _HwId, strlen(_HwId)); //wsa__MessageID存放的是uuid
if(was_Action != NULL)
{
header->wsa__Action = (char*)malloc(1024);
memset(header->wsa__Action, '\0', 1024);
strncpy(header->wsa__Action, was_Action, 1024); //
}
if(was_To != NULL)
{
header->wsa__To = (char *)malloc(1024);
memset(header->wsa__To, '\0', 1024);
strncpy(header->wsa__To, was_To, 1024);//"urn:schemas-xmlsoap-org:ws:2005:04:discovery";
}
soap->header = header;
return soap;
}
//释放函数
void ONVIF_soap_delete(struct soap *soap)
{
soap_destroy(soap); // remove deserialized class instances (C++ only)
soap_end(soap); // Clean up deserialized data (except class instances) and temporary data
soap_free(soap); // Reset and deallocate the context created with soap_new or soap_copy
}
int ONVIF_ClientDiscovery()
{
int FoundDevNo = 0;
int retval = SOAP_OK;
wsdd__ProbeType req; // 用于发送Probe消息
struct __wsdd__ProbeMatches resp; // 用于接收Probe应答
wsdd__ScopesType sScope;
struct SOAP_ENV__Header header;
struct soap* soap;
const char *was_To = "urn:schemas-xmlsoap-org:ws:2005:04:discovery";
const char *was_Action = "http://schemas.xmlsoap.org/ws/2005/04/discovery/Probe";
//IP Adress and PortNo, broadCast
const char *soap_endpoint = "soap.udp://239.255.255.250:3702/"; //设备上服务器监听239.255.255.250的3702端口
//Create new soap object with info
soap = ONVIF_Initsoap(&header, was_To, was_Action, 10);
soap_default_SOAP_ENV__Header(soap, &header);
soap->header = &header;
soap_default_wsdd__ScopesType(soap, &sScope); // 设置寻找设备的范围
sScope.__item = NULL;
soap_default_wsdd__ProbeType(soap, &req); // 设置寻找设备的类型
req.Scopes = &sScope;
req.Types = NULL; //"dn:NetworkVideoTransmitter";
//sent the message broadcast and wait
retval = soap_send___wsdd__Probe(soap, soap_endpoint, NULL, &req); // 向组播地址广播Probe消息
while(retval == SOAP_OK)
{
printf("**************1**************\n");
retval = soap_recv___wsdd__ProbeMatches(soap, &resp);
if(retval == SOAP_OK)
{
if(soap->error)
{
printf("[%d]:recv soap error :%d, %s, %s\n", __LINE__, soap->error, *soap_faultcode(soap), *soap_faultstring(soap));
retval = soap->error;
}
else //we find a device
{
FoundDevNo++;
if(resp.wsdd__ProbeMatches->ProbeMatch != NULL && resp.wsdd__ProbeMatches->ProbeMatch->XAddrs != NULL)
{
printf("***** No %d Devices Information *****\n", FoundDevNo);
printf("Device Service Address : %s\r\n", resp.wsdd__ProbeMatches->ProbeMatch->XAddrs);
printf("Device EP Address : %s\r\n", resp.wsdd__ProbeMatches->ProbeMatch->wsa__EndpointReference.Address);
printf("Device Type : %s\r\n", resp.wsdd__ProbeMatches->ProbeMatch->Types);
printf("Device Metadata Version: %d\r\n", resp.wsdd__ProbeMatches->ProbeMatch->MetadataVersion);
printf("[%d]*********************************\n", __LINE__);
}
}
}
else if(soap->error)
{
if(FoundDevNo == 0)
{
printf("No Device found!\n");
retval = soap->error;
}
else
{
printf("Search end! Find %d Device! \n", FoundDevNo);
retval = 0;
}
break;
}
}
//释放函数
ONVIF_soap_delete(soap);
return retval;
}
int main(int argc, char *argv[])
{
if(ONVIF_ClientDiscovery() != 0)
{
printf("discover failed! \n");
return -1;
}
return 0;
}
6、在编译时如果出现：对‘namespaces’未定义的引用，那是你在程序中没有加 #include "wsdd.nsmap" ，这个头文件，加上即可。
7、编译，生成可执行文件test：gcc -o test search_test.c stdsoap2.c soapC.c soapClient.c -I import/
8、运行test： ./test
设备搜索已完成！
设备搜索的主要目的是获取他服务器的地址：http://172.168.0.216/onvif/device_service，为下一步获取能力做准备。
来源：oschina
链接：https://my.oschina.net/u/4315991/blog/3580226