Tweak CHAOS TXT local.api.ftl

patch/civetweb.sh

@@ -20,4 +20,7 @@ patch -p1 < patch/civetweb/0001-Register-CSRF-token-in-conn-request_info.patch
 echo "Applying patch 0001-Log-debug-messages-to-webserver.log-when-debug.webse.patch"
 patch -p1 < patch/civetweb/0001-Log-debug-messages-to-webserver.log-when-debug.webse.patch
 
+echo "Applying patch 0001-Expose-bound-to-addresses-from-CivetWeb-to-the-front.patch"
+patch -p1 < patch/civetweb/0001-Expose-bound-to-addresses-from-CivetWeb-to-the-front.patch
+
 echo "ALL PATCHES APPLIED OKAY"

patch/civetweb/0001-Expose-bound-to-addresses-from-CivetWeb-to-the-front.patch

@@ -0,0 +1,50 @@
+From 0bee9e9f7942c5b73a715eaeadf5ab2d09a8c74d Mon Sep 17 00:00:00 2001
+From: DL6ER <[email protected]>
+Date: Sat, 22 Feb 2025 18:33:25 +0100
+Subject: [PATCH] Expose bound-to addresses from CivetWeb to the frontend
+
+Signed-off-by: DL6ER <[email protected]>
+---
+ src/webserver/civetweb/civetweb.c | 1 +
+ src/webserver/civetweb/civetweb.h | 6 ++++++
+ 2 files changed, 7 insertions(+)
+
+diff --git a/src/webserver/civetweb/civetweb.c b/src/webserver/civetweb/civetweb.c
+index fa908e54..66fcab01 100644
+--- a/src/webserver/civetweb/civetweb.c
++++ b/src/webserver/civetweb/civetweb.c
+@@ -3339,6 +3339,7 @@ mg_get_server_ports(const struct mg_context *ctx,
+ 		ports[cnt].is_ssl = ctx->listening_sockets[i].is_ssl;
+ 		ports[cnt].is_redirect = ctx->listening_sockets[i].ssl_redir;
+ 		ports[cnt].is_optional = ctx->listening_sockets[i].is_optional;
++		memcpy(&ports[cnt].addr, &ctx->listening_sockets[i].lsa, sizeof(ports[cnt].addr));
+
+ 		if (ctx->listening_sockets[i].lsa.sa.sa_family == AF_INET) {
+ 			/* IPv4 */
+diff --git a/src/webserver/civetweb/civetweb.h b/src/webserver/civetweb/civetweb.h
+index eee958b4..6dcfa457 100644
+--- a/src/webserver/civetweb/civetweb.h
++++ b/src/webserver/civetweb/civetweb.h
+@@ -23,6 +23,8 @@
+ #ifndef CIVETWEB_HEADER_INCLUDED
+ #define CIVETWEB_HEADER_INCLUDED
+
++#include <netinet/in.h> /* Pi-hole extension */
++
+ #define CIVETWEB_VERSION "1.17"
+ #define CIVETWEB_VERSION_MAJOR (1)
+ #define CIVETWEB_VERSION_MINOR (17)
+@@ -721,6 +723,10 @@ struct mg_server_port {
+ 	int _reserved2;
+ 	int _reserved3;
+ 	int _reserved4;
++   union {
++     struct sockaddr_in sa4; /* Pi-hole extension */
++     struct sockaddr_in6 sa6; /* Pi-hole extension */
++   } addr;
+ };
+
+ /* Legacy name */
+-- 
+2.43.0
+

src/webserver/civetweb/civetweb.c

@@ -3339,6 +3339,7 @@ mg_get_server_ports(const struct mg_context *ctx,
 		ports[cnt].is_ssl = ctx->listening_sockets[i].is_ssl;
 		ports[cnt].is_redirect = ctx->listening_sockets[i].ssl_redir;
 		ports[cnt].is_optional = ctx->listening_sockets[i].is_optional;
+		memcpy(&ports[cnt].addr, &ctx->listening_sockets[i].lsa, sizeof(ports[cnt].addr));
 
 		if (ctx->listening_sockets[i].lsa.sa.sa_family == AF_INET) {
 			/* IPv4 */

src/webserver/civetweb/civetweb.h

@@ -23,6 +23,8 @@
 #ifndef CIVETWEB_HEADER_INCLUDED
 #define CIVETWEB_HEADER_INCLUDED
 
+#include <netinet/in.h> /* Pi-hole extension */
+
 #define CIVETWEB_VERSION "1.17"
 #define CIVETWEB_VERSION_MAJOR (1)
 #define CIVETWEB_VERSION_MINOR (17)
@@ -721,6 +723,10 @@ struct mg_server_port {
 	int _reserved2;
 	int _reserved3;
 	int _reserved4;
+   union {
+     struct sockaddr_in sa4; /* Pi-hole extension */
+     struct sockaddr_in6 sa6; /* Pi-hole extension */
+   } addr;
 };
 
 /* Legacy name */

src/webserver/webserver.c

@@ -207,8 +207,9 @@ static struct serverports
 	bool is_secure :1;
 	bool is_redirect :1;
 	bool is_optional :1;
-	unsigned char protocol; // 1 = IPv4, 2 = IPv4+IPv6, 3 = IPv6
-	in_port_t port;
+	char addr[INET6_ADDRSTRLEN + 2]; // +2 for square brackets around IPv6 address
+	int port;
+	int protocol; // 1 = IPv4, 3 = IPv6
 } server_ports[MAXPORTS] = { 0 };
 static in_port_t https_port = 0;
 /**
@@ -252,20 +253,37 @@ static void get_server_ports(void)
 		server_ports[i].is_secure = mgports[i].is_ssl;
 		server_ports[i].is_redirect = mgports[i].is_redirect;
 		server_ports[i].is_optional = mgports[i].is_optional;
+		// 1 = IPv4, 3 = IPv6 (can also be a combo-socker serving both),
+		// the documentation in civetweb.h is wrong
 		server_ports[i].protocol = mgports[i].protocol;
 
+		// Convert listening address to string
+		if(server_ports[i].protocol == 1)
+			inet_ntop(AF_INET, &mgports[i].addr.sa4.sin_addr, server_ports[i].addr, INET_ADDRSTRLEN);
+		else if(server_ports[i].protocol == 3)
+		{
+			char tmp[INET6_ADDRSTRLEN] = { 0 };
+			inet_ntop(AF_INET6, &mgports[i].addr.sa6.sin6_addr, tmp, INET6_ADDRSTRLEN);
+			// Enclose IPv6 address in square brackets
+			snprintf(server_ports[i].addr, sizeof(server_ports[i].addr), "[%s]", tmp);
+		}
+		else
+			log_warn("Unsupported protocol for port %d", mgports[i].port);
+
 		// Store (first) HTTPS port if not already set
 		if(mgports[i].is_ssl && https_port == 0)
 			https_port = mgports[i].port;
 
 		// Print port information
 		if(i == 0)
 			log_info("Web server ports:");
-		log_info("  - %d (HTTP%s, IPv%s%s%s)",
-		         mgports[i].port, mgports[i].is_ssl ? "S" : "",
-		         mgports[i].protocol == 1 ? "4" : (mgports[i].protocol == 3 ? "6" : "4+6"),
-		         mgports[i].is_redirect ? ", redirecting" : "",
-		         mgports[i].is_optional ? ", optional" : "");
+		log_info("  - %s:%d (HTTP%s, IPv%s%s%s)",
+		         server_ports[i].addr,
+		         server_ports[i].port,
+		         server_ports[i].is_secure ? "S" : "",
+		         server_ports[i].protocol == 1 ? "4" : "6",
+		         server_ports[i].is_redirect ? ", redirecting" : "",
+		         server_ports[i].is_optional ? ", optional" : "");
 
 	}
 }
@@ -275,21 +293,13 @@ in_port_t __attribute__((pure)) get_https_port(void)
 	return https_port;
 }
 
+#define MAX_URL_LEN 255
 unsigned short get_api_string(char **buf, const bool domain)
 {
 	// Initialize buffer to empty string
 	size_t len = 0;
 	// First byte has the length of the first string
 	**buf = 0;
-	const char *domain_str = domain ? config.webserver.domain.v.s : "pi.hole";
-	size_t api_str_size = strlen(domain_str) + 20;
-
-	// Check if the string is too long for the TXT record
-	if(api_str_size > 255)
-	{
-		log_err("API URL too long for TXT record!");
-		return 0;
-	}
 
 	// TXT record format:
 	//
@@ -311,20 +321,30 @@ unsigned short get_api_string(char **buf, const bool domain)
 			continue;
 
 		// Reallocate additional memory for every port
-		if((*buf = realloc(*buf, (i+1)*api_str_size)) == NULL)
+		const size_t bufsz = (i + 1) * MAX_URL_LEN;
+		if((*buf = realloc(*buf, bufsz)) == NULL)
 		{
 			log_err("Failed to reallocate API URL buffer!");
 			return 0;
 		}
-		const size_t bufsz = (i+1)*api_str_size;
+
+		// Use appropriate domain
+		const char *addr = domain ? config.webserver.domain.v.s : server_ports[i].addr;
+
+		// If we bound to the wildcard address, substitute it with
+		// 127.0.0.1
+		if(strcmp(addr, "0.0.0.0") == 0)
+			addr = "127.0.0.1";
+		else if(strcasecmp(addr, "[::]") == 0)
+			addr = "[::1]";
 
 		// Append API URL to buffer
 		// We add this at buffer + 1 because the first byte is the
 		// length of the string, which we don't know yet
-		char *api_str = calloc(api_str_size, sizeof(char));
-		const ssize_t this_len = snprintf(api_str, bufsz - len - 1, "http%s://%s:%d/api/",
+		char *api_str = calloc(MAX_URL_LEN, sizeof(char));
+		const ssize_t this_len = snprintf(api_str, MAX_URL_LEN, "http%s://%s:%d/api/",
 		                                  server_ports[i].is_secure ? "s" : "",
-		                                  domain_str, server_ports[i].port);
+		                                  addr, server_ports[i].port);
 		// Check if snprintf() failed
 		if(this_len < 0)
 		{

test/test_suite.bats

@@ -1179,7 +1179,7 @@
 @test "API addresses reported correctly by CHAOS TXT local.api.ftl" {
   run bash -c 'dig CHAOS TXT local.api.ftl +short @127.0.0.1'
   printf "dig (full): %s\n" "${lines[@]}"
-  [[ ${lines[0]} == '"http://pi.hole:80/api/" "https://pi.hole:443/api/"' ]]
+  [[ ${lines[0]} == '"http://127.0.0.1:80/api/" "https://127.0.0.1:443/api/" "http://[::1]:80/api/" "https://[::1]:443/api/"' ]]
 }
 
 @test "API addresses reported by CHAOS TXT api.ftl identical to domain.api.ftl" {