diff options
Diffstat (limited to 'src/libsystemd-dhcp/sd-dhcp-client.c')
| -rw-r--r-- | src/libsystemd-dhcp/sd-dhcp-client.c | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/src/libsystemd-dhcp/sd-dhcp-client.c b/src/libsystemd-dhcp/sd-dhcp-client.c index ee6e89eacb..0c82260dfd 100644 --- a/src/libsystemd-dhcp/sd-dhcp-client.c +++ b/src/libsystemd-dhcp/sd-dhcp-client.c @@ -886,8 +886,18 @@ static int client_receive_message_raw(sd_event_source *s, int fd, uint32_t revents, void *userdata) { sd_dhcp_client *client = userdata; _cleanup_free_ DHCPPacket *packet = NULL; - int buflen = 0, len, r; usec_t time_now; + uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))]; + struct iovec iov = {}; + struct msghdr msg = { + .msg_iov = &iov, + .msg_iovlen = 1, + .msg_control = cmsgbuf, + .msg_controllen = sizeof(cmsgbuf), + }; + struct cmsghdr *cmsg; + bool checksum = true; + int buflen = 0, len, r; assert(s); assert(client); @@ -901,11 +911,26 @@ static int client_receive_message_raw(sd_event_source *s, int fd, if (!packet) return -ENOMEM; - len = read(fd, packet, buflen); - if (len < 0) + iov.iov_base = packet; + iov.iov_len = buflen; + + len = recvmsg(fd, &msg, 0); + if (len < 0) { + log_dhcp_client(client, "could not receive message from raw " + "socket: %s", strerror(errno)); return 0; + } + + 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); + + checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY); + break; + } + } - r = dhcp_packet_verify_headers(packet, len); + r = dhcp_packet_verify_headers(packet, len, checksum); if (r < 0) return 0; |