| 1 | --- a/networking/udhcp/dhcpc.c |
| 2 | +++ b/networking/udhcp/dhcpc.c |
| 3 | @@ -26,8 +26,8 @@ |
| 4 | #include "dhcpc.h" |
| 5 | |
| 6 | #include <netinet/if_ether.h> |
| 7 | -#include <netpacket/packet.h> |
| 8 | #include <linux/filter.h> |
| 9 | +#include <linux/if_packet.h> |
| 10 | |
| 11 | /* struct client_config_t client_config is in bb_common_bufsiz1 */ |
| 12 | |
| 13 | @@ -846,17 +846,41 @@ static int send_release(uint32_t server, |
| 14 | static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) |
| 15 | { |
| 16 | int bytes; |
| 17 | + int nocsum = 0; |
| 18 | struct ip_udp_dhcp_packet packet; |
| 19 | uint16_t check; |
| 20 | + unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))]; |
| 21 | + struct iovec iov = { |
| 22 | + .iov_base = &packet, |
| 23 | + .iov_len = sizeof(packet), |
| 24 | + }; |
| 25 | + struct msghdr msg = { |
| 26 | + .msg_iov = &iov, |
| 27 | + .msg_iovlen = 1, |
| 28 | + .msg_control = cmsgbuf, |
| 29 | + .msg_controllen = sizeof(cmsgbuf), |
| 30 | + }; |
| 31 | + struct cmsghdr *cmsg; |
| 32 | |
| 33 | memset(&packet, 0, sizeof(packet)); |
| 34 | - bytes = safe_read(fd, &packet, sizeof(packet)); |
| 35 | + do { |
| 36 | + bytes = recvmsg(fd, &msg, 0); |
| 37 | + } while (bytes < 0 && errno == EINTR); |
| 38 | + |
| 39 | if (bytes < 0) { |
| 40 | log1("Packet read error, ignoring"); |
| 41 | /* NB: possible down interface, etc. Caller should pause. */ |
| 42 | return bytes; /* returns -1 */ |
| 43 | } |
| 44 | |
| 45 | + for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { |
| 46 | + if (cmsg->cmsg_level == SOL_PACKET && |
| 47 | + cmsg->cmsg_type == PACKET_AUXDATA) { |
| 48 | + struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg); |
| 49 | + nocsum = aux->tp_status & TP_STATUS_CSUMNOTREADY; |
| 50 | + } |
| 51 | + } |
| 52 | + |
| 53 | if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) { |
| 54 | log1("Packet is too short, ignoring"); |
| 55 | return -2; |
| 56 | @@ -896,7 +920,7 @@ static NOINLINE int udhcp_recv_raw_packe |
| 57 | packet.ip.tot_len = packet.udp.len; /* yes, this is needed */ |
| 58 | check = packet.udp.check; |
| 59 | packet.udp.check = 0; |
| 60 | - if (check && check != udhcp_checksum(&packet, bytes)) { |
| 61 | + if (!nocsum && check && check != udhcp_checksum(&packet, bytes)) { |
| 62 | log1("Packet with bad UDP checksum received, ignoring"); |
| 63 | return -2; |
| 64 | } |
| 65 | @@ -942,6 +966,7 @@ static int udhcp_raw_socket(int ifindex) |
| 66 | { |
| 67 | int fd; |
| 68 | struct sockaddr_ll sock; |
| 69 | + int val; |
| 70 | |
| 71 | /* |
| 72 | * Comment: |
| 73 | @@ -1008,6 +1033,13 @@ static int udhcp_raw_socket(int ifindex) |
| 74 | log1("Attached filter to raw socket fd %d", fd); // log? |
| 75 | } |
| 76 | |
| 77 | + val = 1; |
| 78 | + if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA, &val, |
| 79 | + sizeof(val)) < 0) { |
| 80 | + if (errno != ENOPROTOOPT) |
| 81 | + log1("Failed to set auxiliary packet data for socket fd %d", fd); |
| 82 | + } |
| 83 | + |
| 84 | log1("Created raw socket"); |
| 85 | |
| 86 | return fd; |
| 87 | |
