--- a/networking/udhcp/dhcpc.c +++ b/networking/udhcp/dhcpc.c @@ -26,8 +26,8 @@ #include "dhcpc.h" #include -#include #include +#include /* struct client_config_t client_config is in bb_common_bufsiz1 */ @@ -846,17 +846,41 @@ static int send_release(uint32_t server, static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) { int bytes; + int nocsum = 0; struct ip_udp_dhcp_packet packet; uint16_t check; + unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))]; + struct iovec iov = { + .iov_base = &packet, + .iov_len = sizeof(packet), + }; + struct msghdr msg = { + .msg_iov = &iov, + .msg_iovlen = 1, + .msg_control = cmsgbuf, + .msg_controllen = sizeof(cmsgbuf), + }; + struct cmsghdr *cmsg; memset(&packet, 0, sizeof(packet)); - bytes = safe_read(fd, &packet, sizeof(packet)); + do { + bytes = recvmsg(fd, &msg, 0); + } while (bytes < 0 && errno == EINTR); + if (bytes < 0) { log1("Packet read error, ignoring"); /* NB: possible down interface, etc. Caller should pause. */ return bytes; /* returns -1 */ } + for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { + if (cmsg->cmsg_level == SOL_PACKET && + cmsg->cmsg_type == PACKET_AUXDATA) { + struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg); + nocsum = aux->tp_status & TP_STATUS_CSUMNOTREADY; + } + } + if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) { log1("Packet is too short, ignoring"); return -2; @@ -896,7 +920,7 @@ static NOINLINE int udhcp_recv_raw_packe packet.ip.tot_len = packet.udp.len; /* yes, this is needed */ check = packet.udp.check; packet.udp.check = 0; - if (check && check != udhcp_checksum(&packet, bytes)) { + if (!nocsum && check && check != udhcp_checksum(&packet, bytes)) { log1("Packet with bad UDP checksum received, ignoring"); return -2; } @@ -942,6 +966,7 @@ static int udhcp_raw_socket(int ifindex) { int fd; struct sockaddr_ll sock; + int val; /* * Comment: @@ -1008,6 +1033,13 @@ static int udhcp_raw_socket(int ifindex) log1("Attached filter to raw socket fd %d", fd); // log? } + val = 1; + if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA, &val, + sizeof(val)) < 0) { + if (errno != ENOPROTOOPT) + log1("Failed to set auxiliary packet data for socket fd %d", fd); + } + log1("Created raw socket"); return fd;