Merge pull request #15570 from poettering/cmsg-find

[thirdparty/systemd.git] / src / libsystemd-network / sd-dhcp-client.c

diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c
index a59ae4767e2b6acd9256b05c600b7cfa0f4ad94c..0cff6c4f33dfc165f65383c6124459e0a3c04e25 100644 (file)
--- a/src/libsystemd-network/sd-dhcp-client.c
+++ b/src/libsystemd-network/sd-dhcp-client.c
@@ -1927,25 +1927,21 @@ static int client_receive_message_raw(
 
         iov = IOVEC_MAKE(packet, buflen);
 
-        len = recvmsg(fd, &msg, 0);
-        if (len < 0) {
-                if (IN_SET(errno, EAGAIN, EINTR, ENETDOWN))
-                        return 0;
-
-                return log_dhcp_client_errno(client, errno,
-                                             "Could not receive message from raw socket: %m");
-        } else if ((size_t)len < sizeof(DHCPPacket))
+        len = recvmsg_safe(fd, &msg, 0);
+        if (IN_SET(len, -EAGAIN, -EINTR, -ENETDOWN))
                 return 0;
+        if (len < 0)
+                return log_dhcp_client_errno(client, len,
+                                             "Could not receive message from raw socket: %m");
 
-        CMSG_FOREACH(cmsg, &msg)
-                if (cmsg->cmsg_level == SOL_PACKET &&
-                    cmsg->cmsg_type == PACKET_AUXDATA &&
-                    cmsg->cmsg_len == CMSG_LEN(sizeof(struct tpacket_auxdata))) {
-                        struct tpacket_auxdata *aux = (struct tpacket_auxdata*)CMSG_DATA(cmsg);
+        if ((size_t) len < sizeof(DHCPPacket))
+                return 0;
 
-                        checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
-                        break;
-                }
+        cmsg = cmsg_find(&msg, SOL_PACKET, PACKET_AUXDATA, CMSG_LEN(sizeof(struct tpacket_auxdata)));
+        if (cmsg) {
+                struct tpacket_auxdata *aux = (struct tpacket_auxdata*) CMSG_DATA(cmsg);
+                checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
+        }
 
         r = dhcp_packet_verify_headers(packet, len, checksum, client->port);
         if (r < 0)