From b7f370c0143567f9f475c12ddadb5910b9eb74b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= <maze@google.com>
Date: Wed, 6 May 2020 13:36:55 -0700
Subject: [PATCH] libnetutils/packet.c - fix a socket leak on bind error
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and clean up the code a little bit while at it.

Test: builds, atest
Bug: 155297277
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I01a10e36f852cde1b93a91f95b51294a434885ab
---
 libnetutils/packet.c | 25 +++++++++++--------------
 libnetutils/packet.h |  4 +++-
 2 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/libnetutils/packet.c b/libnetutils/packet.c
index 9ecdd4f4e..2debc282f 100644
--- a/libnetutils/packet.c
+++ b/libnetutils/packet.c
@@ -37,25 +37,22 @@
 
 #include "dhcpmsg.h"
 
-int fatal();
+int fatal(const char*);
 
-int open_raw_socket(const char *ifname __attribute__((unused)), uint8_t *hwaddr, int if_index)
-{
-    int s;
-    struct sockaddr_ll bindaddr;
+int open_raw_socket(const char* ifname __unused, uint8_t hwaddr[ETH_ALEN], int if_index) {
+    int s = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
+    if (s < 0) return fatal("socket(PF_PACKET)");
 
-    if((s = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP))) < 0) {
-        return fatal("socket(PF_PACKET)");
-    }
-
-    memset(&bindaddr, 0, sizeof(bindaddr));
-    bindaddr.sll_family = AF_PACKET;
-    bindaddr.sll_protocol = htons(ETH_P_IP);
-    bindaddr.sll_halen = ETH_ALEN;
+    struct sockaddr_ll bindaddr = {
+            .sll_family = AF_PACKET,
+            .sll_protocol = htons(ETH_P_IP),
+            .sll_ifindex = if_index,
+            .sll_halen = ETH_ALEN,
+    };
     memcpy(bindaddr.sll_addr, hwaddr, ETH_ALEN);
-    bindaddr.sll_ifindex = if_index;
 
     if (bind(s, (struct sockaddr *)&bindaddr, sizeof(bindaddr)) < 0) {
+        close(s);
         return fatal("Cannot bind raw socket to interface");
     }
 
diff --git a/libnetutils/packet.h b/libnetutils/packet.h
index aade392df..66186fcba 100644
--- a/libnetutils/packet.h
+++ b/libnetutils/packet.h
@@ -17,7 +17,9 @@
 #ifndef _WIFI_PACKET_H_
 #define _WIFI_PACKET_H_
 
-int open_raw_socket(const char *ifname, uint8_t *hwaddr, int if_index);
+#include <linux/if_ether.h>
+
+int open_raw_socket(const char* ifname, uint8_t hwaddr[ETH_ALEN], int if_index);
 int send_packet(int s, int if_index, struct dhcp_msg *msg, int size,
                 uint32_t saddr, uint32_t daddr, uint32_t sport, uint32_t dport);
 int receive_packet(int s, struct dhcp_msg *msg);