DHCP not working

Question

Hi all, I am using ioLibrary_Driver-master for DHCP, I am not getting any response from the DHCP. /* PARSE REPLY pDHCPMSG */ int8_t parseDHCPMSG(void) { uint8_t svr_addr[6]; uint16_t svr_port; uint16_t len; uint8_t * p; uint8_t * e; uint8_t type = 0; uint8_t opt_len; if((len = getSn_RX_RSR(DHCP_SOCKET)) > 0) { len = recvfrom(DHCP_SOCKET, (uint8_t *)pDHCPMSG, len, svr_addr, &svr_port); #ifdef DHCP_DEBUG printf(“DHCP message : %d.%d.%d.%d(%d) %d received. ”,svr_addr[0],svr_addr[1],svr_addr[2], svr_addr[3],svr_port, len); #endif } else return 0; if (svr_port == DHCP_SERVER_PORT) { // compare mac address if ( (pDHCPMSG->chaddr[0] != DHCP_CHADDR[0]) || (pDHCPMSG->chaddr[1] != DHCP_CHADDR[1]) || (pDHCPMSG->chaddr[2] != DHCP_CHADDR[2]) || (pDHCPMSG->chaddr[3] != DHCP_CHADDR[3]) || (pDHCPMSG->chaddr[4] != DHCP_CHADDR[4]) || (pDHCPMSG->chaddr[5] != DHCP_CHADDR[5]) ) return 0; p = (uint8_t *)(&pDHCPMSG->op); p = p + 240; // 240 = sizeof(RIP_MSG) + MAGIC_COOKIE size in RIP_MSG.opt - sizeof(RIP_MSG.opt) e = p + (len - 240); while ( p < e ) { switch ( *p ) { case endOption : p = e; // for break while(p < e) break; case padOption : p++; break; case dhcpMessageType : p++; p++; type = *p++; break; case subnetMask : p++; p++; DHCP_allocated_sn[0] = *p++; DHCP_allocated_sn[1] = *p++; DHCP_allocated_sn[2] = *p++; DHCP_allocated_sn[3] = *p++; break; case routersOnSubnet : p++; opt_len = *p++; DHCP_allocated_gw[0] = *p++; DHCP_allocated_gw[1] = *p++; DHCP_allocated_gw[2] = *p++; DHCP_allocated_gw[3] = *p++; p = p + (opt_len - 4); break; case dns : p++; opt_len = *p++; DHCP_allocated_dns[0] = *p++; DHCP_allocated_dns[1] = *p++; DHCP_allocated_dns[2] = *p++; DHCP_allocated_dns[3] = *p++; p = p + (opt_len - 4); break; case dhcpIPaddrLeaseTime : p++; opt_len = *p++; dhcp_lease_time = *p++; dhcp_lease_time = (dhcp_lease_time << 8) + *p++; dhcp_lease_time = (dhcp_lease_time << 8) + *p++; dhcp_lease_time = (dhcp_lease_time << 8) + *p++; #ifdef _DHCP_DEBUG_ dhcp_lease_time = 10; #endif break; case dhcpServerIdentifier : p++; opt_len = *p++; DHCP_SIP[0] = *p++; DHCP_SIP[1] = *p++; DHCP_SIP[2] = *p++; DHCP_SIP[3] = *p++; break; default : p++; opt_len = *p++; p += opt_len; break; } // switch } // while } // if return type; } for the above function I am always getting 0 response. Please help me out, what could be the mistake and any error on DHCP init. Thanks.

taylor · Answer

Hello, How did you initialize DHCP()? Here is ‘W5500 Application code examples’, please refer this example. https://wizwiki.net/wiki/doku.php?id=products:w5500:driver w5500_example_dhcp_stm32f103x_coide_20131226 Wireshark is a network packet analyzer. First of all, check dhcp request packet please. Here is a sample of DHCP traffic. https://wiki.wireshark.org/SampleCaptures?action=AttachFile&do=get&target=dhcp.pcap thanks best regards taylor