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	eab4e6fedd
	
	
	
		
			
			Defined in https://tools.ietf.org/html/rfc6762#section-11: All Multicast DNS responses (including responses sent via unicast) SHOULD be sent with IP TTL set to 255
		
			
				
	
	
		
			348 lines
		
	
	
		
			9.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			348 lines
		
	
	
		
			9.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| 
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| /*
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|  * MDNS Server Networking
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|  *
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|  */
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| #include <string.h>
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| #include "mdns_networking.h"
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| #include "esp_log.h"
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| #include "esp_netif_net_stack.h"
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| 
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| 
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| extern mdns_server_t * _mdns_server;
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| 
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| /*
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|  * MDNS Server Networking
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|  *
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|  */
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| static const char *TAG = "MDNS_Networking";
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| 
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| static struct udp_pcb * _pcb_main = NULL;
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| 
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| static void _udp_recv(void *arg, struct udp_pcb *upcb, struct pbuf *pb, const ip_addr_t *raddr, uint16_t rport);
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| 
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| /**
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|  * @brief  Low level UDP PCB Initialize
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|  */
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| static esp_err_t _udp_pcb_main_init(void)
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| {
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|     if(_pcb_main) {
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|         return ESP_OK;
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|     }
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|     _pcb_main = udp_new();
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|     if (!_pcb_main) {
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|         return ESP_ERR_NO_MEM;
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|     }
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|     if (udp_bind(_pcb_main, IP_ANY_TYPE, MDNS_SERVICE_PORT) != 0) {
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|         udp_remove(_pcb_main);
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|         _pcb_main = NULL;
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|         return ESP_ERR_INVALID_STATE;
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|     }
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|     _pcb_main->mcast_ttl = 255;
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|     _pcb_main->remote_port = MDNS_SERVICE_PORT;
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|     ip_addr_copy(_pcb_main->remote_ip, *(IP_ANY_TYPE));
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|     udp_recv(_pcb_main, &_udp_recv, _mdns_server);
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|     return ESP_OK;
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| }
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| 
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| /**
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|  * @brief  Low level UDP PCB Free
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|  */
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| static void _udp_pcb_main_deinit(void)
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| {
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|     if(_pcb_main){
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|         udp_recv(_pcb_main, NULL, NULL);
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|         udp_disconnect(_pcb_main);
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|         udp_remove(_pcb_main);
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|         _pcb_main = NULL;
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|     }
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| }
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| 
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| /**
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|  * @brief  Low level UDP Multicast membership control
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|  */
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| static esp_err_t _udp_join_group(mdns_if_t if_inx, mdns_ip_protocol_t ip_protocol, bool join)
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| {
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|     struct netif * netif = NULL;
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|     esp_netif_t *tcpip_if = _mdns_get_esp_netif(if_inx);
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| 
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|     if (!esp_netif_is_netif_up(tcpip_if)) {
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|         // Network interface went down before event propagated, skipping IGMP config
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|         return ESP_ERR_INVALID_STATE;
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|     }
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| 
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|     netif = esp_netif_get_netif_impl(tcpip_if);
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|     assert(netif);
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| 
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|     if (ip_protocol == MDNS_IP_PROTOCOL_V4) {
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|         ip4_addr_t multicast_addr;
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|         IP4_ADDR(&multicast_addr, 224, 0, 0, 251);
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| 
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|         if(join){
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|             if (igmp_joingroup_netif(netif, &multicast_addr)) {
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|                 return ESP_ERR_INVALID_STATE;
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|             }
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|         } else {
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|             if (igmp_leavegroup_netif(netif, &multicast_addr)) {
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|                 return ESP_ERR_INVALID_STATE;
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|             }
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|         }
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|     }
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| #if CONFIG_LWIP_IPV6
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|     else {
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|         ip_addr_t multicast_addr = IPADDR6_INIT(0x000002ff, 0, 0, 0xfb000000);
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| 
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|         if(join){
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|             if (mld6_joingroup_netif(netif, &(multicast_addr.u_addr.ip6))) {
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|                 return ESP_ERR_INVALID_STATE;
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|             }
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|         } else {
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|             if (mld6_leavegroup_netif(netif, &(multicast_addr.u_addr.ip6))) {
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|                 return ESP_ERR_INVALID_STATE;
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|             }
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|         }
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|     }
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| #endif
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|     return ESP_OK;
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| }
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| 
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| /**
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|  * @brief  the receive callback of the raw udp api. Packets are received here
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|  *
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|  */
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| static void _udp_recv(void *arg, struct udp_pcb *upcb, struct pbuf *pb, const ip_addr_t *raddr, uint16_t rport)
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| {
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| 
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|     uint8_t i;
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|     while (pb != NULL) {
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|         struct pbuf * this_pb = pb;
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|         pb = pb->next;
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|         this_pb->next = NULL;
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| 
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|         mdns_rx_packet_t * packet = (mdns_rx_packet_t *)malloc(sizeof(mdns_rx_packet_t));
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|         if (!packet) {
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|             HOOK_MALLOC_FAILED;
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|             //missed packet - no memory
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|             pbuf_free(this_pb);
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|             continue;
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|         }
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| 
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|         packet->tcpip_if = MDNS_IF_MAX;
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|         packet->pb = this_pb;
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|         packet->src_port = rport;
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| #if CONFIG_LWIP_IPV6
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|         packet->src.type = raddr->type;
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|         memcpy(&packet->src.u_addr, &raddr->u_addr, sizeof(raddr->u_addr));
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| #else
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|         packet->src.type = IPADDR_TYPE_V4;
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|         memcpy(&packet->src.u_addr.ip4, &raddr->addr, sizeof(ip_addr_t));
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| #endif
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|         packet->dest.type = packet->src.type;
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| 
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|         if (packet->src.type == IPADDR_TYPE_V4) {
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|             packet->ip_protocol = MDNS_IP_PROTOCOL_V4;
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|             struct ip_hdr * iphdr = (struct ip_hdr *)(((uint8_t *)(packet->pb->payload)) - UDP_HLEN - IP_HLEN);
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|             packet->dest.u_addr.ip4.addr = iphdr->dest.addr;
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|             packet->multicast = ip4_addr_ismulticast(&(packet->dest.u_addr.ip4));
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|         }
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| #if CONFIG_LWIP_IPV6
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|         else {
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|             packet->ip_protocol = MDNS_IP_PROTOCOL_V6;
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|             struct ip6_hdr * ip6hdr = (struct ip6_hdr *)(((uint8_t *)(packet->pb->payload)) - UDP_HLEN - IP6_HLEN);
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|             memcpy(&packet->dest.u_addr.ip6.addr, (uint8_t *)ip6hdr->dest.addr, 16);
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|             packet->multicast = ip6_addr_ismulticast(&(packet->dest.u_addr.ip6));
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|         }
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| #endif
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| 
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|         //lwip does not return the proper pcb if you have more than one for the same multicast address (but different interfaces)
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|         struct netif * netif = NULL;
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|         struct udp_pcb * pcb = NULL;
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|         for (i=0; i<MDNS_IF_MAX; i++) {
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|             pcb = _mdns_server->interfaces[i].pcbs[packet->ip_protocol].pcb;
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|             netif = esp_netif_get_netif_impl(_mdns_get_esp_netif(i));
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|             if (pcb && netif && netif == ip_current_input_netif ()) {
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|                 if (packet->src.type == IPADDR_TYPE_V4) {
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| #if CONFIG_LWIP_IPV6
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|                     if ((packet->src.u_addr.ip4.addr & netif->netmask.u_addr.ip4.addr) != (netif->ip_addr.u_addr.ip4.addr & netif->netmask.u_addr.ip4.addr)) {
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| #else
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|                     if ((packet->src.u_addr.ip4.addr & netif->netmask.addr) != (netif->ip_addr.addr & netif->netmask.addr)) {
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| #endif                  //packet source is not in the same subnet
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|                         pcb = NULL;
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|                         break;
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|                     }
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|                 }
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|                 packet->tcpip_if = i;
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|                 break;
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|             }
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|             pcb = NULL;
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|         }
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| 
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|         if (!pcb || !_mdns_server || !_mdns_server->action_queue
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|           || _mdns_send_rx_action(packet) != ESP_OK) {
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|             pbuf_free(this_pb);
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|             free(packet);
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|         }
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|     }
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| 
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| }
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| 
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| /**
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|  * @brief  Check if any of the interfaces is up
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|  */
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| static bool _udp_pcb_is_in_use(void){
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|     int i, p;
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|     for (i=0; i<MDNS_IF_MAX; i++) {
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|         for (p=0; p<MDNS_IP_PROTOCOL_MAX; p++) {
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|             if(_mdns_server->interfaces[i].pcbs[p].pcb){
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|                 return true;
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|             }
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|         }
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|     }
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|     return false;
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| }
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| 
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| /**
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|  * @brief  Stop PCB Main code
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|  */
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| static void _udp_pcb_deinit(mdns_if_t tcpip_if, mdns_ip_protocol_t ip_protocol)
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| {
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|     if (!_mdns_server) {
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|         return;
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|     }
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|     mdns_pcb_t * _pcb = &_mdns_server->interfaces[tcpip_if].pcbs[ip_protocol];
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|     if (_pcb->pcb) {
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|         free(_pcb->probe_services);
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|         _pcb->state = PCB_OFF;
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|         _pcb->pcb = NULL;
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|         _pcb->probe_ip = false;
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|         _pcb->probe_services = NULL;
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|         _pcb->probe_services_len = 0;
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|         _pcb->probe_running = false;
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|         _pcb->failed_probes = 0;
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|         _udp_join_group(tcpip_if, ip_protocol, false);
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|         if(!_udp_pcb_is_in_use()) {
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|             _udp_pcb_main_deinit();
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|         }
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|     }
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| }
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| 
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| /**
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|  * @brief  Start PCB Main code
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|  */
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| static esp_err_t _udp_pcb_init(mdns_if_t tcpip_if, mdns_ip_protocol_t ip_protocol)
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| {
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|     if (!_mdns_server || _mdns_server->interfaces[tcpip_if].pcbs[ip_protocol].pcb) {
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|         return ESP_ERR_INVALID_STATE;
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|     }
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| 
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|     esp_err_t err = _udp_join_group(tcpip_if, ip_protocol, true);
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|     if(err){
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|         return err;
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|     }
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| 
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|     err = _udp_pcb_main_init();
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|     if(err){
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|         return err;
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|     }
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| 
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|     _mdns_server->interfaces[tcpip_if].pcbs[ip_protocol].pcb = _pcb_main;
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|     _mdns_server->interfaces[tcpip_if].pcbs[ip_protocol].failed_probes = 0;
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|     return ESP_OK;
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| }
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| 
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| typedef struct {
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|     struct tcpip_api_call_data call;
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|     mdns_if_t tcpip_if;
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|     mdns_ip_protocol_t ip_protocol;
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|     struct pbuf *pbt;
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|     const ip_addr_t *ip;
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|     uint16_t port;
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|     esp_err_t err;
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| } mdns_api_call_t;
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| 
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| /**
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|  * @brief  Start PCB from LwIP thread
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|  */
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| static err_t _mdns_pcb_init_api(struct tcpip_api_call_data *api_call_msg)
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| {
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|     mdns_api_call_t * msg = (mdns_api_call_t *)api_call_msg;
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|     msg->err = _udp_pcb_init(msg->tcpip_if, msg->ip_protocol);
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|     return msg->err;
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| }
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| 
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| /**
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|  * @brief  Stop PCB from LwIP thread
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|  */
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| static err_t _mdns_pcb_deinit_api(struct tcpip_api_call_data *api_call_msg)
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| {
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|     mdns_api_call_t * msg = (mdns_api_call_t *)api_call_msg;
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|     _udp_pcb_deinit(msg->tcpip_if, msg->ip_protocol);
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|     msg->err = ESP_OK;
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|     return ESP_OK;
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| }
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| 
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| /*
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|  * Non-static functions below are
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|  *  - _mdns prefixed
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|  *  - commented in mdns_networking.h header
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|  */
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| esp_err_t _mdns_pcb_init(mdns_if_t tcpip_if, mdns_ip_protocol_t ip_protocol)
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| {
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|     mdns_api_call_t msg = {
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|         .tcpip_if = tcpip_if,
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|         .ip_protocol = ip_protocol
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|     };
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|     tcpip_api_call(_mdns_pcb_init_api, &msg.call);
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|     return msg.err;
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| }
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| 
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| esp_err_t _mdns_pcb_deinit(mdns_if_t tcpip_if, mdns_ip_protocol_t ip_protocol)
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| {
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|     mdns_api_call_t msg = {
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|         .tcpip_if = tcpip_if,
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|         .ip_protocol = ip_protocol
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|     };
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|     tcpip_api_call(_mdns_pcb_deinit_api, &msg.call);
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|     return msg.err;
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| }
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| 
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| static err_t _mdns_udp_pcb_write_api(struct tcpip_api_call_data *api_call_msg)
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| {
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|     void * nif = NULL;
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|     mdns_api_call_t * msg = (mdns_api_call_t *)api_call_msg;
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|     mdns_pcb_t * _pcb = &_mdns_server->interfaces[msg->tcpip_if].pcbs[msg->ip_protocol];
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|     nif = esp_netif_get_netif_impl(_mdns_get_esp_netif(msg->tcpip_if));
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|     if (!nif) {
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|         pbuf_free(msg->pbt);
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|         msg->err = ERR_IF;
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|         return ERR_IF;
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|     }
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|     esp_err_t err = udp_sendto_if (_pcb->pcb, msg->pbt, msg->ip, msg->port, (struct netif *)nif);
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|     pbuf_free(msg->pbt);
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|     msg->err = err;
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|     return err;
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| }
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| 
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| size_t _mdns_udp_pcb_write(mdns_if_t tcpip_if, mdns_ip_protocol_t ip_protocol, const esp_ip_addr_t *ip, uint16_t port, uint8_t * data, size_t len)
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| {
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|     struct pbuf* pbt = pbuf_alloc(PBUF_TRANSPORT, len, PBUF_RAM);
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|     if (pbt == NULL) {
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|         return 0;
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|     }
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|     memcpy((uint8_t *)pbt->payload, data, len);
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| 
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|     mdns_api_call_t msg = {
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|         .tcpip_if = tcpip_if,
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|         .ip_protocol = ip_protocol,
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|         .pbt = pbt,
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|         .ip = (ip_addr_t *)ip,
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|         .port = port
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|     };
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|     tcpip_api_call(_mdns_udp_pcb_write_api, &msg.call);
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| 
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|     if (msg.err) {
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|         return 0;
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|     }
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|     return len;
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| }
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