42 	/* Computing the checksum over just the IPv4 header--including its  in rmnet_map_ipv4_dl_csum_trailer()
43 	 * checksum field--should yield 0.  If it doesn't, the IP header  in rmnet_map_ipv4_dl_csum_trailer()
51 	/* We don't support checksum offload on IPv4 fragments */  in rmnet_map_ipv4_dl_csum_trailer()
57 	/* Checksum offload is only supported for UDP and TCP protocols */  in rmnet_map_ipv4_dl_csum_trailer()
64 	/* RFC 768: UDP checksum is optional for IPv4, and is 0 if unused */  in rmnet_map_ipv4_dl_csum_trailer()
70 	/* The checksum value in the trailer is computed over the entire  in rmnet_map_ipv4_dl_csum_trailer()
72 	 * transport checksum from this, we first subract the contribution  in rmnet_map_ipv4_dl_csum_trailer()
73 	 * of the IP header from the trailer checksum.  We then add the  in rmnet_map_ipv4_dl_csum_trailer()
74 	 * checksum computed over the pseudo header.  in rmnet_map_ipv4_dl_csum_trailer()
77 	 * trailer checksum.  Therefore the checksum in the trailer is  in rmnet_map_ipv4_dl_csum_trailer()
78 	 * just the checksum computed over the IP payload.  in rmnet_map_ipv4_dl_csum_trailer()
81 	 * checksum to the IP payload checksum will yield 0xffff (negative  in rmnet_map_ipv4_dl_csum_trailer()
82 	 * zero).  This means the trailer checksum and the pseudo checksum  in rmnet_map_ipv4_dl_csum_trailer()
84 	 * message passes the checksum test if the trailer checksum value  in rmnet_map_ipv4_dl_csum_trailer()
85 	 * is the negated pseudo header checksum.  in rmnet_map_ipv4_dl_csum_trailer()
88 	 * header checksum value; it is already accounted for in the  in rmnet_map_ipv4_dl_csum_trailer()
89 	 * checksum value found in the trailer.  in rmnet_map_ipv4_dl_csum_trailer()
119 	/* Checksum offload is only supported for UDP and TCP protocols;  in rmnet_map_ipv6_dl_csum_trailer()
128 	/* The checksum value in the trailer is computed over the entire  in rmnet_map_ipv6_dl_csum_trailer()
130 	 * transport checksum from this, we first subract the contribution  in rmnet_map_ipv6_dl_csum_trailer()
131 	 * of the IP header from the trailer checksum.  We then add the  in rmnet_map_ipv6_dl_csum_trailer()
132 	 * checksum computed over the pseudo header.  in rmnet_map_ipv6_dl_csum_trailer()
141 	/* It's sufficient to compare the IP payload checksum with the  in rmnet_map_ipv6_dl_csum_trailer()
142 	 * negated pseudo checksum to determine whether the packet  in rmnet_map_ipv6_dl_csum_trailer()
143 	 * checksum was good.  (See further explanation in comments  in rmnet_map_ipv6_dl_csum_trailer()
280 			/* Ask for checksum offloading */  in rmnet_map_v5_checksum_uplink_packet()
399  * padding + checksum trailer.
471 /* Generates UL checksum meta info header for IPv4 and IPv6 over TCP and UDP
472  * packets that are supported for UL checksum offload.