From 5ed3e9a6a118d8721c8af5206a660175328255fb Mon Sep 17 00:00:00 2001
From: xieqinan <xieqinan@espressif.com>
Date: Wed, 15 Mar 2023 11:19:00 +0800
Subject: [PATCH] mdns: append all ipv6 address in mdns answer

---
 components/mdns/mdns.c                        | 44 +++++++++++--------
 .../mdns/private_include/mdns_private.h       |  6 +++
 .../esp_netif_linux/esp_netif_linux.c         | 23 ++++++++++
 3 files changed, 55 insertions(+), 18 deletions(-)

diff --git a/components/mdns/mdns.c b/components/mdns/mdns.c
index 957c5e480..f4d201ee8 100644
--- a/components/mdns/mdns.c
+++ b/components/mdns/mdns.c
@@ -1385,32 +1385,40 @@ static uint8_t _mdns_append_answer(uint8_t *packet, uint16_t *index, mdns_out_an
 #if CONFIG_LWIP_IPV6
     else if (answer->type == MDNS_TYPE_AAAA) {
         if (answer->host == &_mdns_self_host) {
-            struct esp_ip6_addr if_ip6;
-            if (!_mdns_server->interfaces[tcpip_if].pcbs[MDNS_IP_PROTOCOL_V6].pcb && _mdns_server->interfaces[tcpip_if].pcbs[MDNS_IP_PROTOCOL_V6].state != PCB_DUP) {
+            struct esp_ip6_addr if_ip6s[NETIF_IPV6_MAX_NUMS];
+            uint8_t count = 0;
+            if (!_mdns_server->interfaces[tcpip_if].pcbs[MDNS_IP_PROTOCOL_V6].pcb &&
+                    _mdns_server->interfaces[tcpip_if].pcbs[MDNS_IP_PROTOCOL_V6].state != PCB_DUP) {
                 return 0;
             }
-            if (esp_netif_get_ip6_linklocal(_mdns_get_esp_netif(tcpip_if), &if_ip6)) {
-                return 0;
-            }
-            if (_ipv6_address_is_zero(if_ip6)) {
-                return 0;
-            }
-            if (_mdns_append_aaaa_record(packet, index, _mdns_server->hostname, (uint8_t *)if_ip6.addr, answer->flush, answer->bye) <= 0) {
-                return 0;
+            count = esp_netif_get_all_ip6(_mdns_get_esp_netif(tcpip_if), if_ip6s);
+            assert(count <= NETIF_IPV6_MAX_NUMS);
+            for (int i = 0; i < count; i++) {
+                if (_ipv6_address_is_zero(if_ip6s[i])) {
+                    return 0;
+                }
+                if (_mdns_append_aaaa_record(packet, index, _mdns_server->hostname, (uint8_t *)if_ip6s[i].addr,
+                                             answer->flush, answer->bye) <= 0) {
+                    return 0;
+                }
             }
             if (!_mdns_if_is_dup(tcpip_if)) {
-                return 1;
+                return count;
             }
-            mdns_if_t other_if = _mdns_get_other_if (tcpip_if);
-            if (esp_netif_get_ip6_linklocal(_mdns_get_esp_netif(other_if), &if_ip6)) {
-                return 1;
+
+            mdns_if_t other_if = _mdns_get_other_if(tcpip_if);
+            struct esp_ip6_addr other_ip6;
+            if (esp_netif_get_ip6_linklocal(_mdns_get_esp_netif(other_if), &other_ip6)) {
+                return count;
             }
-            if (_mdns_append_aaaa_record(packet, index, _mdns_server->hostname, (uint8_t *)if_ip6.addr, answer->flush, answer->bye) > 0) {
-                return 2;
+            if (_mdns_append_aaaa_record(packet, index, _mdns_server->hostname, (uint8_t *)other_ip6.addr,
+                                         answer->flush, answer->bye) > 0) {
+                return 1 + count;
             }
-            return 1;
+            return count;
         } else if (answer->host != NULL) {
-            return _mdns_append_host_answer(packet, index, answer->host, ESP_IPADDR_TYPE_V6, answer->flush, answer->bye);
+            return _mdns_append_host_answer(packet, index, answer->host, ESP_IPADDR_TYPE_V6, answer->flush,
+                                            answer->bye);
         }
     }
 #endif
diff --git a/components/mdns/private_include/mdns_private.h b/components/mdns/private_include/mdns_private.h
index b6f35e16c..b0368a95b 100644
--- a/components/mdns/private_include/mdns_private.h
+++ b/components/mdns/private_include/mdns_private.h
@@ -33,6 +33,12 @@
 #endif
 #define MDNS_MAX_PREDEF_INTERFACES (CONFIG_MDNS_PREDEF_NETIF_STA + CONFIG_MDNS_PREDEF_NETIF_AP + CONFIG_MDNS_PREDEF_NETIF_ETH)
 
+#ifdef CONFIG_LWIP_IPV6_NUM_ADDRESSES
+#define NETIF_IPV6_MAX_NUMS CONFIG_LWIP_IPV6_NUM_ADDRESSES
+#else
+#define NETIF_IPV6_MAX_NUMS 3
+#endif
+
 /** Number of configured interfaces */
 #if MDNS_MAX_PREDEF_INTERFACES > CONFIG_MDNS_MAX_INTERFACES
 #warning Number of configured interfaces is less then number of predefined interfaces. Please update CONFIG_MDNS_MAX_INTERFACES.
diff --git a/components/mdns/tests/host_test/components/esp_netif_linux/esp_netif_linux.c b/components/mdns/tests/host_test/components/esp_netif_linux/esp_netif_linux.c
index 03a7193b4..67837239a 100644
--- a/components/mdns/tests/host_test/components/esp_netif_linux/esp_netif_linux.c
+++ b/components/mdns/tests/host_test/components/esp_netif_linux/esp_netif_linux.c
@@ -64,6 +64,29 @@ esp_err_t esp_netif_dhcpc_get_status(esp_netif_t *esp_netif, esp_netif_dhcp_stat
     return ESP_OK;
 }
 
+int esp_netif_get_all_ip6(esp_netif_t *esp_netif, esp_ip6_addr_t if_ip6[])
+{
+    if (esp_netif == NULL) {
+        return 0;
+    }
+    struct ifaddrs *addrs, *tmp;
+    int addr_count = 0;
+    getifaddrs(&addrs);
+    tmp = addrs;
+
+    while (tmp) {
+        if (tmp->ifa_addr && tmp->ifa_addr->sa_family == AF_INET6) {
+            struct sockaddr_in6 *pAddr = (struct sockaddr_in6 *)tmp->ifa_addr;
+            if (strcmp(esp_netif->if_desc, tmp->ifa_name) == 0) {
+                memcpy(&if_ip6[addr_count++], &pAddr->sin6_addr, 4 * 4);
+            }
+        }
+        tmp = tmp->ifa_next;
+    }
+
+    freeifaddrs(addrs);
+    return addr_count;
+}
 
 esp_err_t esp_netif_get_ip6_linklocal(esp_netif_t *esp_netif, esp_ip6_addr_t *if_ip6)
 {