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-rw-r--r--networking/udhcp/clientpacket.c25
-rw-r--r--networking/udhcp/dhcpc.c2
-rw-r--r--networking/udhcp/packet.c73
3 files changed, 55 insertions, 45 deletions
diff --git a/networking/udhcp/clientpacket.c b/networking/udhcp/clientpacket.c
index 0347310..b8190ba 100644
--- a/networking/udhcp/clientpacket.c
+++ b/networking/udhcp/clientpacket.c
@@ -167,39 +167,40 @@ int send_release(uint32_t server, uint32_t ciaddr)
}
-/* return -1 on errors that are fatal for the socket, -2 for those that aren't */
+/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
int get_raw_packet(struct dhcpMessage *payload, int fd)
{
int bytes;
struct udp_dhcp_packet packet;
uint16_t check;
- memset(&packet, 0, sizeof(struct udp_dhcp_packet));
- bytes = read(fd, &packet, sizeof(struct udp_dhcp_packet));
+ memset(&packet, 0, sizeof(packet));
+ bytes = safe_read(fd, &packet, sizeof(packet));
if (bytes < 0) {
DEBUG("Cannot read on raw listening socket - ignoring");
sleep(1); /* possible down interface, looping condition */
- return -1;
+ return bytes; /* returns -1 */
}
- if (bytes < (int) (sizeof(struct iphdr) + sizeof(struct udphdr))) {
- DEBUG("Message too short, ignoring");
+ if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
+ DEBUG("Packet is too short, ignoring");
return -2;
}
if (bytes < ntohs(packet.ip.tot_len)) {
- DEBUG("Truncated packet");
+ /* packet is bigger than sizeof(packet), we did partial read */
+ DEBUG("Oversized packet, ignoring");
return -2;
}
/* ignore any extra garbage bytes */
bytes = ntohs(packet.ip.tot_len);
- /* Make sure its the right packet for us, and that it passes sanity checks */
+ /* make sure its the right packet for us, and that it passes sanity checks */
if (packet.ip.protocol != IPPROTO_UDP || packet.ip.version != IPVERSION
|| packet.ip.ihl != (sizeof(packet.ip) >> 2)
|| packet.udp.dest != htons(CLIENT_PORT)
- || bytes > (int) sizeof(struct udp_dhcp_packet)
+ /* || bytes > (int) sizeof(packet) - can't happen */
|| ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
) {
DEBUG("Unrelated/bogus packet");
@@ -211,12 +212,12 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
packet.ip.check = 0;
if (check != udhcp_checksum(&packet.ip, sizeof(packet.ip))) {
DEBUG("Bad IP header checksum, ignoring");
- return -1;
+ return -2;
}
/* verify UDP checksum. IP header has to be modified for this */
memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
- /* fields which are not memset: protocol, check, saddr, daddr */
+ /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
check = packet.udp.check;
packet.udp.check = 0;
@@ -228,7 +229,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
memcpy(payload, &packet.data, bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
if (payload->cookie != htonl(DHCP_MAGIC)) {
- bb_error_msg("received bogus message (bad magic) - ignoring");
+ bb_error_msg("received bogus message (bad magic), ignoring");
return -2;
}
DEBUG("Got valid DHCP packet");
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 3de389f..d76a62c 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -454,7 +454,7 @@ int udhcpc_main(int argc, char **argv)
len = udhcp_recv_packet(&packet, sockfd);
else len = get_raw_packet(&packet, sockfd);
- if (len == -1 && errno != EINTR) {
+ if (len == -1) { /* error is severe, reopen socket */
DEBUG("error on read, %s, reopening socket", strerror(errno));
change_listen_mode(listen_mode); /* just close and reopen */
}
diff --git a/networking/udhcp/packet.c b/networking/udhcp/packet.c
index 22c18de..443fea6 100644
--- a/networking/udhcp/packet.c
+++ b/networking/udhcp/packet.c
@@ -41,20 +41,14 @@ void udhcp_init_header(struct dhcpMessage *packet, char type)
/* read a packet from socket fd, return -1 on read error, -2 on packet error */
int udhcp_recv_packet(struct dhcpMessage *packet, int fd)
{
-#if 0
- static const char broken_vendors[][8] = {
- "MSFT 98",
- ""
- };
-#endif
int bytes;
unsigned char *vendor;
memset(packet, 0, sizeof(*packet));
- bytes = read(fd, packet, sizeof(*packet));
+ bytes = safe_read(fd, packet, sizeof(*packet));
if (bytes < 0) {
DEBUG("cannot read on listening socket, ignoring");
- return -1;
+ return bytes; /* returns -1 */
}
if (packet->cookie != htonl(DHCP_MAGIC)) {
@@ -67,6 +61,10 @@ int udhcp_recv_packet(struct dhcpMessage *packet, int fd)
vendor = get_option(packet, DHCP_VENDOR);
if (vendor) {
#if 0
+ static const char broken_vendors[][8] = {
+ "MSFT 98",
+ ""
+ };
int i;
for (i = 0; broken_vendors[i][0]; i++) {
if (vendor[OPT_LEN - 2] == (uint8_t)strlen(broken_vendors[i])
@@ -127,10 +125,11 @@ int udhcp_send_raw_packet(struct dhcpMessage *payload,
uint32_t source_ip, int source_port,
uint32_t dest_ip, int dest_port, const uint8_t *dest_arp, int ifindex)
{
- int fd;
- int result;
struct sockaddr_ll dest;
struct udp_dhcp_packet packet;
+ int fd;
+ int result = -1;
+ const char *msg;
enum {
IP_UPD_DHCP_SIZE = sizeof(struct udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
@@ -139,8 +138,8 @@ int udhcp_send_raw_packet(struct dhcpMessage *payload,
fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
if (fd < 0) {
- bb_perror_msg("socket");
- return -1;
+ msg = "socket(%s)";
+ goto ret_msg;
}
memset(&dest, 0, sizeof(dest));
@@ -152,10 +151,9 @@ int udhcp_send_raw_packet(struct dhcpMessage *payload,
dest.sll_ifindex = ifindex;
dest.sll_halen = 6;
memcpy(dest.sll_addr, dest_arp, 6);
- if (bind(fd, (struct sockaddr *)&dest, sizeof(struct sockaddr_ll)) < 0) {
- bb_perror_msg("bind");
- close(fd);
- return -1;
+ if (bind(fd, (struct sockaddr *)&dest, sizeof(dest)) < 0) {
+ msg = "bind(%s)";
+ goto ret_close;
}
packet.ip.protocol = IPPROTO_UDP;
@@ -179,11 +177,15 @@ int udhcp_send_raw_packet(struct dhcpMessage *payload,
* If you need to change this: last byte of the packet is
* packet.data.options[end_option(packet.data.options)]
*/
- result = sendto(fd, &packet, IP_UPD_DHCP_SIZE, 0, (struct sockaddr *) &dest, sizeof(dest));
- if (result <= 0) {
- bb_perror_msg("sendto");
- }
+ result = sendto(fd, &packet, IP_UPD_DHCP_SIZE, 0,
+ (struct sockaddr *) &dest, sizeof(dest));
+ msg = "sendto";
+ ret_close:
close(fd);
+ if (result < 0) {
+ ret_msg:
+ bb_perror_msg(msg, "PACKET");
+ }
return result;
}
@@ -193,41 +195,48 @@ int udhcp_send_kernel_packet(struct dhcpMessage *payload,
uint32_t source_ip, int source_port,
uint32_t dest_ip, int dest_port)
{
- int fd, result;
struct sockaddr_in client;
+ int fd;
+ int result = -1;
+ const char *msg;
enum {
DHCP_SIZE = sizeof(struct dhcpMessage) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
};
fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
- if (fd < 0)
- return -1;
-
+ if (fd < 0) {
+ msg = "socket(%s)";
+ goto ret_msg;
+ }
setsockopt_reuseaddr(fd);
memset(&client, 0, sizeof(client));
client.sin_family = AF_INET;
client.sin_port = htons(source_port);
client.sin_addr.s_addr = source_ip;
-
if (bind(fd, (struct sockaddr *)&client, sizeof(client)) == -1) {
- close(fd);
- return -1;
+ msg = "bind(%s)";
+ goto ret_close;
}
memset(&client, 0, sizeof(client));
client.sin_family = AF_INET;
client.sin_port = htons(dest_port);
client.sin_addr.s_addr = dest_ip;
-
- if (connect(fd, (struct sockaddr *)&client, sizeof(struct sockaddr)) == -1) {
- close(fd);
- return -1;
+ if (connect(fd, (struct sockaddr *)&client, sizeof(client)) == -1) {
+ msg = "connect";
+ goto ret_close;
}
/* Currently we send full-sized DHCP packets (see above) */
- result = write(fd, payload, DHCP_SIZE);
+ result = safe_write(fd, payload, DHCP_SIZE);
+ msg = "write";
+ ret_close:
close(fd);
+ if (result < 0) {
+ ret_msg:
+ bb_perror_msg(msg, "UDP");
+ }
return result;
}
generated by cgit v1.1 at 2024-11-06 18:30:32 +0000