From 15b8d49dba3eac76be0491e5183a06bdbc312948 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Duval?= <jerome.duval@gmail.com>
Date: Sat, 21 Nov 2020 23:55:48 +0100
Subject: [PATCH] ipv4: have IP_MULTICAST_TTL accept 1-byte buffers

this is a common length for this socket option. also denies values greater als 255.

Change-Id: I3d480444d655c41e76d3bbc6625f72c1c4eb3808
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3409
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
---
 .../kernel/network/protocols/ipv4/ipv4.cpp    | 41 ++++++++++++++++++-
 1 file changed, 39 insertions(+), 2 deletions(-)

diff --git a/src/add-ons/kernel/network/protocols/ipv4/ipv4.cpp b/src/add-ons/kernel/network/protocols/ipv4/ipv4.cpp
index 6c5f142606..9e539932e1 100644
--- a/src/add-ons/kernel/network/protocols/ipv4/ipv4.cpp
+++ b/src/add-ons/kernel/network/protocols/ipv4/ipv4.cpp
@@ -792,6 +792,19 @@ get_int_option(void* target, size_t length, int value)
 }
 
 
+static status_t
+get_char_int_option(void* target, size_t length, int value)
+{
+	if (length == sizeof(int))
+		return user_memcpy(target, &value, sizeof(int));
+	if (length == sizeof(unsigned char)) {
+		unsigned char uvalue = value;
+		return user_memcpy(target, &uvalue, sizeof(uvalue));
+	}
+	return B_BAD_VALUE;
+}
+
+
 template<typename Type> static status_t
 set_int_option(Type &target, const void* _value, size_t length)
 {
@@ -808,6 +821,30 @@ set_int_option(Type &target, const void* _value, size_t length)
 }
 
 
+template<typename Type> static status_t
+set_char_int_option(Type &target, const void* _value, size_t length)
+{
+	if (length == sizeof(int)) {
+		int value;
+		if (user_memcpy(&value, _value, sizeof(int)) != B_OK)
+			return B_BAD_ADDRESS;
+		if (value > 255)
+			return B_BAD_VALUE;
+		target = value;
+		return B_OK;
+	}
+	if (length == sizeof(unsigned char)) {
+		unsigned char value;
+		if (user_memcpy(&value, _value, sizeof(value)) != B_OK)
+			return B_BAD_ADDRESS;
+
+		target = value;
+		return B_OK;
+	}
+	return B_BAD_VALUE;
+}
+
+
 static net_protocol_module_info*
 receiving_protocol(uint8 protocol)
 {
@@ -1145,7 +1182,7 @@ ipv4_getsockopt(net_protocol* _protocol, int level, int option, void* value,
 		if (option == IP_TOS)
 			return get_int_option(value, *_length, protocol->service_type);
 		if (option == IP_MULTICAST_TTL) {
-			return get_int_option(value, *_length,
+			return get_char_int_option(value, *_length,
 				protocol->multicast_time_to_live);
 		}
 		if (option == IP_ADD_MEMBERSHIP
@@ -1253,7 +1290,7 @@ ipv4_setsockopt(net_protocol* _protocol, int level, int option,
 			return B_OK;
 		}
 		if (option == IP_MULTICAST_TTL) {
-			return set_int_option(protocol->multicast_time_to_live, value,
+			return set_char_int_option(protocol->multicast_time_to_live, value,
 				length);
 		}
 		if (option == IP_ADD_MEMBERSHIP || option == IP_DROP_MEMBERSHIP) {