From: Roy Marples <roy@marples.name>
Date: Thu, 15 May 2008 11:12:44 +0000 (+0000)
Subject: Fix some valgrind errors, and work on Linux again.
X-Git-Tag: v4.0.2~402
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3581b92aa447e9a29952aafc13d74aaa38415abf;p=thirdparty%2Fdhcpcd.git

Fix some valgrind errors, and work on Linux again.
---

diff --git a/bpf.c b/bpf.c
index 7d429533..46a08c55 100644
--- a/bpf.c
+++ b/bpf.c
@@ -153,22 +153,24 @@ get_packet(struct interface *iface, void *data, ssize_t len)
 {
 	struct bpf_hdr packet;
 	struct ether_header hw;
-	ssize_t cur_len;
+	ssize_t bytes;
 	const unsigned char *payload, *d;
 
+	if ((size_t)len > iface->buffer_size) {
+		errno = ENOBUFS;
+		return -1;
+	}
 	for (;;) {
 		if (iface->buffer_len == 0) {
-			cur_len = read(iface->fd, iface->buffer,
-				       iface->buffer_size);
-			if (cur_len == -1)
+			bytes = read(iface->fd, iface->buffer,
+				     iface->buffer_size);
+			if (bytes == -1)
 				return errno == EAGAIN ? 0 : -1;
-			else if ((size_t)cur_len < sizeof(packet))
+			else if ((size_t)bytes < sizeof(packet))
 				return -1;
-			iface->buffer_len = cur_len;
+			iface->buffer_len = bytes;
 		}
-
-		cur_len = -1;
-
+		bytes = -1;
 		memcpy(&packet, iface->buffer + iface->buffer_pos,
 		       sizeof(packet));
 		if (packet.bh_caplen != packet.bh_datalen)
@@ -179,19 +181,23 @@ get_packet(struct interface *iface, void *data, ssize_t len)
 		memcpy(&hw, iface->buffer + packet.bh_hdrlen, sizeof(hw));
 		payload = iface->buffer + packet.bh_hdrlen + sizeof(hw);
 		if (hw.ether_type == htons(ETHERTYPE_ARP)) {
-			cur_len = packet.bh_caplen - sizeof(hw);
-			memcpy(data, payload, len);
+			bytes = packet.bh_caplen - sizeof(hw);
+			if (bytes > len)
+				bytes = len;
+			memcpy(data, payload, bytes);
 		} else if (valid_udp_packet(payload) >= 0) {
-			cur_len = get_udp_data(&d, payload);
-			memcpy(data, d, cur_len);
+			bytes = get_udp_data(&d, payload);
+			if (bytes > len)
+				bytes = len;
+			memcpy(data, d, bytes);
 		} else
-			cur_len = -1;
+			bytes = -1;
 next:
 		iface->buffer_pos += BPF_WORDALIGN(packet.bh_hdrlen +
 						   packet.bh_caplen);
 		if (iface->buffer_pos >= iface->buffer_len)
 			iface->buffer_len = iface->buffer_pos = 0;
-		if (cur_len != -1)
-			return cur_len;
+		if (bytes != -1)
+			return bytes;
 	}
 }
diff --git a/client.c b/client.c
index 9639e85c..9d143348 100644
--- a/client.c
+++ b/client.c
@@ -1188,7 +1188,8 @@ handle_packet(struct if_state *state, const struct options *options)
 	 * the first one fails for any reason, we can use the next. */
 
 	dhcp = xmalloc(sizeof(*dhcp));
-	do {	
+	do {
+		memset(dhcp, 0, sizeof(*dhcp));
 		bytes = get_packet(iface, dhcp, sizeof(*dhcp));
 		if (bytes == -1)
 			break;
@@ -1287,6 +1288,7 @@ eexit:
 		do_socket(state, SOCKET_CLOSED);
 		free_routes(iface->routes);
 		free(iface->clientid);
+		free(iface->buffer);
 		free(iface);
 	}
 
diff --git a/net.c b/net.c
index b79af243..6f7a7dec 100644
--- a/net.c
+++ b/net.c
@@ -285,7 +285,6 @@ read_interface(const char *ifname, _unused int metric)
 	unsigned char *hwaddr = NULL;
 	size_t hwlen = 0;
 	sa_family_t family = 0;
-	unsigned short mtu;
 #ifdef __linux__
 	char *p;
 #endif
@@ -340,7 +339,6 @@ read_interface(const char *ifname, _unused int metric)
 		if (ioctl(s, SIOCSIFMTU, &ifr) == -1)
 			goto eexit;
 	}
-	mtu = ifr.ifr_mtu;
 
 	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 #ifdef __linux__
diff --git a/net.h b/net.h
index 8e5d2b37..e7ed5941 100644
--- a/net.h
+++ b/net.h
@@ -105,7 +105,7 @@ struct interface
 
 	int fd;
 	int udp_fd;
-	size_t buffer_size, buffer_pos, buffer_len;
+	size_t buffer_size, buffer_len, buffer_pos;
 	unsigned char *buffer;
 
 #ifdef __linux__
diff --git a/socket.c b/socket.c
index 136a609b..ecf8f321 100644
--- a/socket.c
+++ b/socket.c
@@ -54,11 +54,8 @@
 #include "net.h"
 #include "bpf-filter.h"
 
-/* A suitably large buffer for all transactions.
- * BPF buffer size is set by the kernel, so no define. */
-#ifdef __linux__
-# define BUFFER_LENGTH 4096
-#endif
+/* A suitably large buffer for all transactions. */
+#define BUFFER_LENGTH 4096
 
 /* Broadcast address for IPoIB */
 static const uint8_t ipv4_bcast_addr[] = {
@@ -91,7 +88,7 @@ setup_packet_filters(void)
 int
 open_socket(struct interface *iface, int protocol)
 {
-	int flags, s;
+	int s;
 	union sockunion {
 		struct sockaddr sa;
 		struct sockaddr_in sin;
@@ -132,7 +129,9 @@ open_socket(struct interface *iface, int protocol)
 		close(iface->fd);
 	iface->fd = s;
 	iface->socket_protocol = protocol;
-	iface->buffer_length = 0;
+	iface->buffer_size = BUFFER_LENGTH;
+	iface->buffer = xmalloc(iface->buffer_size);
+	iface->buffer_len = iface->buffer_pos = 0;
 	return s;
 
 eexit:
@@ -168,29 +167,27 @@ send_raw_packet(const struct interface *iface, int type,
 	return sendto(iface->fd, data, len, 0, &su.sa, sizeof(su));
 }
 
-/* Linux has no need for the buffer as we can read as much as we want.
- * We only have the buffer listed to keep the same API. */
 ssize_t
 get_packet(struct interface *iface, void *data, ssize_t len)
 {
 	ssize_t bytes;
-	struct timespec ts;
 	const uint8_t *p;
 
-	memset(data, 0, len);
-	bytes = read(iface->fd, data, len);
+	bytes = read(iface->fd, iface->buffer, iface->buffer_size);
 
 	if (bytes == -1)
-		return errno == EGAIN ? 0 : -1;
+		return errno == EAGAIN ? 0 : -1;
 
 	/* If it's an ARP reply, then just send it back */
 	if (iface->socket_protocol == ETHERTYPE_ARP)
 		return bytes;
 
-	if (valid_udp_packet(data) != 0)
+	if (valid_udp_packet(iface->buffer) != 0)
 		return -1;
 
-	bytes = get_udp_data(&p, buffer);
-	memmove(data, p, bytes);
+	bytes = get_udp_data(&p, iface->buffer);
+	if (bytes > len)
+		bytes = len;
+	memcpy(data, p, bytes);
 	return bytes;
 }