From 9634668258342789d2a16172c7c86ef51411f458 Mon Sep 17 00:00:00 2001
From: Jakub Jelen <jjelen@redhat.com>
Date: Fri, 2 Aug 2024 09:56:43 +0200
Subject: [PATCH] Conditional compilation of localnetwork matching

Some architectures (esp32) might not have this API.

Fixes: #263

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
---
 ConfigureChecks.cmake                         |  1 +
 config.h.cmake                                |  3 +++
 src/config.c                                  | 20 ++++++++++++++-----
 tests/unittests/CMakeLists.txt                | 12 +++++++----
 .../torture_config_match_localnetwork.c       |  2 ++
 5 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/ConfigureChecks.cmake b/ConfigureChecks.cmake
index 4639f0c1..8765dc6e 100644
--- a/ConfigureChecks.cmake
+++ b/ConfigureChecks.cmake
@@ -64,6 +64,7 @@ check_include_file(arpa/inet.h HAVE_ARPA_INET_H)
 check_include_file(byteswap.h HAVE_BYTESWAP_H)
 check_include_file(glob.h HAVE_GLOB_H)
 check_include_file(valgrind/valgrind.h HAVE_VALGRIND_VALGRIND_H)
+check_include_file(ifaddrs.h HAVE_IFADDRS_H)
 
 if (WIN32)
   check_include_file(io.h HAVE_IO_H)
diff --git a/config.h.cmake b/config.h.cmake
index 9dec02bf..8dce5273 100644
--- a/config.h.cmake
+++ b/config.h.cmake
@@ -58,6 +58,9 @@
 /* Define to 1 if you have the <stdint.h> header file. */
 #cmakedefine HAVE_STDINT_H 1
 
+/* Define to 1 if you have the <ifaddrs.h> header file. */
+#cmakedefine HAVE_IFADDRS_H 1
+
 /* Define to 1 if you have the <openssl/aes.h> header file. */
 #cmakedefine HAVE_OPENSSL_AES_H 1
 
diff --git a/src/config.c b/src/config.c
index 78549a40..774b3566 100644
--- a/src/config.c
+++ b/src/config.c
@@ -39,10 +39,12 @@
 # include <errno.h>
 # include <signal.h>
 # include <sys/wait.h>
-# include <ifaddrs.h>
 # include <net/if.h>
 # include <netinet/in.h>
 #endif
+#ifdef HAVE_IFADDRS_H
+#include <ifaddrs.h>
+#endif
 
 #include "libssh/config_parser.h"
 #include "libssh/config.h"
@@ -639,7 +641,7 @@ ssh_config_make_absolute(ssh_session session,
     return out;
 }
 
-#ifndef _WIN32
+#ifdef HAVE_IFADDRS_H
 /**
  * @brief Checks if host address matches the local network specified.
  *
@@ -730,7 +732,7 @@ ssh_match_localnetwork(const char *addrlist, bool negate)
 
     return (found == (negate ? 0 : 1));
 }
-#endif
+#endif /* HAVE_IFADDRS_H */
 
 static int
 ssh_config_parse_line(ssh_session session,
@@ -955,7 +957,6 @@ ssh_config_parse_line(ssh_session session,
                 args++;
                 break;
 
-#ifndef _WIN32
             case MATCH_LOCALNETWORK:
                 /* Here we match only one argument */
                 p = ssh_config_get_str_tok(&s, NULL);
@@ -968,6 +969,7 @@ ssh_config_parse_line(ssh_session session,
                     SAFE_FREE(x);
                     return -1;
                 }
+#ifdef HAVE_IFADDRS_H
                 rv = match_cidr_address_list(NULL, p, -1);
                 if (rv == -1) {
                     ssh_set_error(session,
@@ -992,9 +994,17 @@ ssh_config_parse_line(ssh_session session,
                 }
 
                 result &= rv;
+#else /* HAVE_IFADDRS_H */
+                ssh_set_error(session,
+                              SSH_FATAL,
+                              "line %d: ERROR - match localnetwork "
+                              "not supported on this platform",
+                              count);
+                SAFE_FREE(x);
+                return -1;
+#endif /* HAVE_IFADDRS_H */
                 args++;
                 break;
-#endif
 
             case MATCH_UNKNOWN:
             default:
diff --git a/tests/unittests/CMakeLists.txt b/tests/unittests/CMakeLists.txt
index a22532a9..79f3856c 100644
--- a/tests/unittests/CMakeLists.txt
+++ b/tests/unittests/CMakeLists.txt
@@ -48,11 +48,15 @@ if (UNIX AND NOT WIN32)
         torture_pki_ed25519
         # requires /dev/null
         torture_channel
-        # requires some non-standard API from netdb.h, in.h
-        # and arpa/inet.h for handling IP addresses
-        torture_config_match_localnetwork
     )
-
+    if (HAVE_IFADDRS_H)
+        set(LIBSSH_UNIT_TESTS
+            ${LIBSSH_UNIT_TESTS}
+            # requires some non-standard API from netdb.h, in.h
+            # and arpa/inet.h for handling IP addresses
+            torture_config_match_localnetwork
+        )
+    endif (HAVE_IFADDRS_H)
     if (WITH_SERVER)
         set(LIBSSH_UNIT_TESTS
             ${LIBSSH_UNIT_TESTS}
diff --git a/tests/unittests/torture_config_match_localnetwork.c b/tests/unittests/torture_config_match_localnetwork.c
index 33ed05d1..80aae0c3 100644
--- a/tests/unittests/torture_config_match_localnetwork.c
+++ b/tests/unittests/torture_config_match_localnetwork.c
@@ -3,7 +3,9 @@
 #include "libssh/options.h"
 #include "libssh/session.h"
 #include "match.c"
+#ifdef HAVE_IFADDRS_H
 #include <ifaddrs.h>
+#endif
 #include <net/if.h>
 #include <stdbool.h>