From 5a6efecf78112f2e882473e6610c9b1f2e1cdada Mon Sep 17 00:00:00 2001
From: Stéphane Raimbault <stephane.raimbault@gmail.com>
Date: Sun, 27 Nov 2022 23:19:29 +0100
Subject: [PATCH] Replace inet_addr by inet_pton calls

---
 src/modbus-tcp.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/modbus-tcp.c b/src/modbus-tcp.c
index 081ceee..410737b 100644
--- a/src/modbus-tcp.c
+++ b/src/modbus-tcp.c
@@ -351,7 +351,16 @@ static int _modbus_tcp_connect(modbus_t *ctx)
 
     addr.sin_family = AF_INET;
     addr.sin_port = htons(ctx_tcp->port);
-    addr.sin_addr.s_addr = inet_addr(ctx_tcp->ip);
+    rc = inet_pton(addr.sin_family, ctx_tcp->ip, &(addr.sin_addr));
+    if (rc <= 0) {
+        if (ctx->debug) {
+            fprintf(stderr, "Invalid IP address: %s\n", ctx_tcp->ip);
+        }
+        close(ctx->s);
+        ctx->s = -1;
+        return -1;
+    }
+
     rc =
         _connect(ctx->s, (struct sockaddr *) &addr, sizeof(addr), &ctx->response_timeout);
     if (rc == -1) {
@@ -495,6 +504,7 @@ int modbus_tcp_listen(modbus_t *ctx, int nb_connection)
     int flags;
     struct sockaddr_in addr;
     modbus_tcp_t *ctx_tcp;
+    int rc;
 
     if (ctx == NULL) {
         errno = EINVAL;
@@ -536,8 +546,17 @@ int modbus_tcp_listen(modbus_t *ctx, int nb_connection)
         addr.sin_addr.s_addr = htonl(INADDR_ANY);
     } else {
         /* Listen only specified IP address */
-        addr.sin_addr.s_addr = inet_addr(ctx_tcp->ip);
+        rc = inet_pton(addr.sin_family, ctx_tcp->ip, &(addr.sin_addr));
+        if (rc <= 0) {
+            if (ctx->debug) {
+                fprintf(stderr, "Invalid IP address: %s\n", ctx_tcp->ip);
+            }
+            close(ctx->s);
+            ctx->s = -1;
+            return -1;
+        }
     }
+
     if (bind(new_s, (struct sockaddr *) &addr, sizeof(addr)) == -1) {
         close(new_s);
         return -1;
--
libgit2 0.21.4