19dcaec04SSubash Abhinov Kasiviswanathan /* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved. 2ceed73a2SSubash Abhinov Kasiviswanathan * 3ceed73a2SSubash Abhinov Kasiviswanathan * This program is free software; you can redistribute it and/or modify 4ceed73a2SSubash Abhinov Kasiviswanathan * it under the terms of the GNU General Public License version 2 and 5ceed73a2SSubash Abhinov Kasiviswanathan * only version 2 as published by the Free Software Foundation. 6ceed73a2SSubash Abhinov Kasiviswanathan * 7ceed73a2SSubash Abhinov Kasiviswanathan * This program is distributed in the hope that it will be useful, 8ceed73a2SSubash Abhinov Kasiviswanathan * but WITHOUT ANY WARRANTY; without even the implied warranty of 9ceed73a2SSubash Abhinov Kasiviswanathan * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10ceed73a2SSubash Abhinov Kasiviswanathan * GNU General Public License for more details. 11ceed73a2SSubash Abhinov Kasiviswanathan * 12ceed73a2SSubash Abhinov Kasiviswanathan * RMNET Data MAP protocol 13ceed73a2SSubash Abhinov Kasiviswanathan * 14ceed73a2SSubash Abhinov Kasiviswanathan */ 15ceed73a2SSubash Abhinov Kasiviswanathan 16ceed73a2SSubash Abhinov Kasiviswanathan #include <linux/netdevice.h> 17bbd21b24SSubash Abhinov Kasiviswanathan #include <linux/ip.h> 18bbd21b24SSubash Abhinov Kasiviswanathan #include <linux/ipv6.h> 19bbd21b24SSubash Abhinov Kasiviswanathan #include <net/ip6_checksum.h> 20ceed73a2SSubash Abhinov Kasiviswanathan #include "rmnet_config.h" 21ceed73a2SSubash Abhinov Kasiviswanathan #include "rmnet_map.h" 22ceed73a2SSubash Abhinov Kasiviswanathan #include "rmnet_private.h" 23ceed73a2SSubash Abhinov Kasiviswanathan 24ceed73a2SSubash Abhinov Kasiviswanathan #define RMNET_MAP_DEAGGR_SPACING 64 25ceed73a2SSubash Abhinov Kasiviswanathan #define RMNET_MAP_DEAGGR_HEADROOM (RMNET_MAP_DEAGGR_SPACING / 2) 26ceed73a2SSubash Abhinov Kasiviswanathan 27bbd21b24SSubash Abhinov Kasiviswanathan static __sum16 *rmnet_map_get_csum_field(unsigned char protocol, 28bbd21b24SSubash Abhinov Kasiviswanathan const void *txporthdr) 29bbd21b24SSubash Abhinov Kasiviswanathan { 30bbd21b24SSubash Abhinov Kasiviswanathan __sum16 *check = NULL; 31bbd21b24SSubash Abhinov Kasiviswanathan 32bbd21b24SSubash Abhinov Kasiviswanathan switch (protocol) { 33bbd21b24SSubash Abhinov Kasiviswanathan case IPPROTO_TCP: 34bbd21b24SSubash Abhinov Kasiviswanathan check = &(((struct tcphdr *)txporthdr)->check); 35bbd21b24SSubash Abhinov Kasiviswanathan break; 36bbd21b24SSubash Abhinov Kasiviswanathan 37bbd21b24SSubash Abhinov Kasiviswanathan case IPPROTO_UDP: 38bbd21b24SSubash Abhinov Kasiviswanathan check = &(((struct udphdr *)txporthdr)->check); 39bbd21b24SSubash Abhinov Kasiviswanathan break; 40bbd21b24SSubash Abhinov Kasiviswanathan 41bbd21b24SSubash Abhinov Kasiviswanathan default: 42bbd21b24SSubash Abhinov Kasiviswanathan check = NULL; 43bbd21b24SSubash Abhinov Kasiviswanathan break; 44bbd21b24SSubash Abhinov Kasiviswanathan } 45bbd21b24SSubash Abhinov Kasiviswanathan 46bbd21b24SSubash Abhinov Kasiviswanathan return check; 47bbd21b24SSubash Abhinov Kasiviswanathan } 48bbd21b24SSubash Abhinov Kasiviswanathan 49bbd21b24SSubash Abhinov Kasiviswanathan static int 50bbd21b24SSubash Abhinov Kasiviswanathan rmnet_map_ipv4_dl_csum_trailer(struct sk_buff *skb, 51bbd21b24SSubash Abhinov Kasiviswanathan struct rmnet_map_dl_csum_trailer *csum_trailer) 52bbd21b24SSubash Abhinov Kasiviswanathan { 53bbd21b24SSubash Abhinov Kasiviswanathan __sum16 *csum_field, csum_temp, pseudo_csum, hdr_csum, ip_payload_csum; 54bbd21b24SSubash Abhinov Kasiviswanathan u16 csum_value, csum_value_final; 55bbd21b24SSubash Abhinov Kasiviswanathan struct iphdr *ip4h; 56bbd21b24SSubash Abhinov Kasiviswanathan void *txporthdr; 57bbd21b24SSubash Abhinov Kasiviswanathan __be16 addend; 58bbd21b24SSubash Abhinov Kasiviswanathan 59bbd21b24SSubash Abhinov Kasiviswanathan ip4h = (struct iphdr *)(skb->data); 60bbd21b24SSubash Abhinov Kasiviswanathan if ((ntohs(ip4h->frag_off) & IP_MF) || 61bbd21b24SSubash Abhinov Kasiviswanathan ((ntohs(ip4h->frag_off) & IP_OFFSET) > 0)) 62bbd21b24SSubash Abhinov Kasiviswanathan return -EOPNOTSUPP; 63bbd21b24SSubash Abhinov Kasiviswanathan 64bbd21b24SSubash Abhinov Kasiviswanathan txporthdr = skb->data + ip4h->ihl * 4; 65bbd21b24SSubash Abhinov Kasiviswanathan 66bbd21b24SSubash Abhinov Kasiviswanathan csum_field = rmnet_map_get_csum_field(ip4h->protocol, txporthdr); 67bbd21b24SSubash Abhinov Kasiviswanathan 68bbd21b24SSubash Abhinov Kasiviswanathan if (!csum_field) 69bbd21b24SSubash Abhinov Kasiviswanathan return -EPROTONOSUPPORT; 70bbd21b24SSubash Abhinov Kasiviswanathan 71bbd21b24SSubash Abhinov Kasiviswanathan /* RFC 768 - Skip IPv4 UDP packets where sender checksum field is 0 */ 72bbd21b24SSubash Abhinov Kasiviswanathan if (*csum_field == 0 && ip4h->protocol == IPPROTO_UDP) 73bbd21b24SSubash Abhinov Kasiviswanathan return 0; 74bbd21b24SSubash Abhinov Kasiviswanathan 75bbd21b24SSubash Abhinov Kasiviswanathan csum_value = ~ntohs(csum_trailer->csum_value); 76bbd21b24SSubash Abhinov Kasiviswanathan hdr_csum = ~ip_fast_csum(ip4h, (int)ip4h->ihl); 77bbd21b24SSubash Abhinov Kasiviswanathan ip_payload_csum = csum16_sub((__force __sum16)csum_value, 78bbd21b24SSubash Abhinov Kasiviswanathan (__force __be16)hdr_csum); 79bbd21b24SSubash Abhinov Kasiviswanathan 80bbd21b24SSubash Abhinov Kasiviswanathan pseudo_csum = ~csum_tcpudp_magic(ip4h->saddr, ip4h->daddr, 81bbd21b24SSubash Abhinov Kasiviswanathan ntohs(ip4h->tot_len) - ip4h->ihl * 4, 82bbd21b24SSubash Abhinov Kasiviswanathan ip4h->protocol, 0); 83bbd21b24SSubash Abhinov Kasiviswanathan addend = (__force __be16)ntohs((__force __be16)pseudo_csum); 84bbd21b24SSubash Abhinov Kasiviswanathan pseudo_csum = csum16_add(ip_payload_csum, addend); 85bbd21b24SSubash Abhinov Kasiviswanathan 86bbd21b24SSubash Abhinov Kasiviswanathan addend = (__force __be16)ntohs((__force __be16)*csum_field); 87bbd21b24SSubash Abhinov Kasiviswanathan csum_temp = ~csum16_sub(pseudo_csum, addend); 88bbd21b24SSubash Abhinov Kasiviswanathan csum_value_final = (__force u16)csum_temp; 89bbd21b24SSubash Abhinov Kasiviswanathan 90bbd21b24SSubash Abhinov Kasiviswanathan if (unlikely(csum_value_final == 0)) { 91bbd21b24SSubash Abhinov Kasiviswanathan switch (ip4h->protocol) { 92bbd21b24SSubash Abhinov Kasiviswanathan case IPPROTO_UDP: 93bbd21b24SSubash Abhinov Kasiviswanathan /* RFC 768 - DL4 1's complement rule for UDP csum 0 */ 94bbd21b24SSubash Abhinov Kasiviswanathan csum_value_final = ~csum_value_final; 95bbd21b24SSubash Abhinov Kasiviswanathan break; 96bbd21b24SSubash Abhinov Kasiviswanathan 97bbd21b24SSubash Abhinov Kasiviswanathan case IPPROTO_TCP: 98bbd21b24SSubash Abhinov Kasiviswanathan /* DL4 Non-RFC compliant TCP checksum found */ 99bbd21b24SSubash Abhinov Kasiviswanathan if (*csum_field == (__force __sum16)0xFFFF) 100bbd21b24SSubash Abhinov Kasiviswanathan csum_value_final = ~csum_value_final; 101bbd21b24SSubash Abhinov Kasiviswanathan break; 102bbd21b24SSubash Abhinov Kasiviswanathan } 103bbd21b24SSubash Abhinov Kasiviswanathan } 104bbd21b24SSubash Abhinov Kasiviswanathan 105bbd21b24SSubash Abhinov Kasiviswanathan if (csum_value_final == ntohs((__force __be16)*csum_field)) 106bbd21b24SSubash Abhinov Kasiviswanathan return 0; 107bbd21b24SSubash Abhinov Kasiviswanathan else 108bbd21b24SSubash Abhinov Kasiviswanathan return -EINVAL; 109bbd21b24SSubash Abhinov Kasiviswanathan } 110bbd21b24SSubash Abhinov Kasiviswanathan 111bbd21b24SSubash Abhinov Kasiviswanathan #if IS_ENABLED(CONFIG_IPV6) 112bbd21b24SSubash Abhinov Kasiviswanathan static int 113bbd21b24SSubash Abhinov Kasiviswanathan rmnet_map_ipv6_dl_csum_trailer(struct sk_buff *skb, 114bbd21b24SSubash Abhinov Kasiviswanathan struct rmnet_map_dl_csum_trailer *csum_trailer) 115bbd21b24SSubash Abhinov Kasiviswanathan { 116bbd21b24SSubash Abhinov Kasiviswanathan __sum16 *csum_field, ip6_payload_csum, pseudo_csum, csum_temp; 117bbd21b24SSubash Abhinov Kasiviswanathan u16 csum_value, csum_value_final; 118bbd21b24SSubash Abhinov Kasiviswanathan __be16 ip6_hdr_csum, addend; 119bbd21b24SSubash Abhinov Kasiviswanathan struct ipv6hdr *ip6h; 120bbd21b24SSubash Abhinov Kasiviswanathan void *txporthdr; 121bbd21b24SSubash Abhinov Kasiviswanathan u32 length; 122bbd21b24SSubash Abhinov Kasiviswanathan 123bbd21b24SSubash Abhinov Kasiviswanathan ip6h = (struct ipv6hdr *)(skb->data); 124bbd21b24SSubash Abhinov Kasiviswanathan 125bbd21b24SSubash Abhinov Kasiviswanathan txporthdr = skb->data + sizeof(struct ipv6hdr); 126bbd21b24SSubash Abhinov Kasiviswanathan csum_field = rmnet_map_get_csum_field(ip6h->nexthdr, txporthdr); 127bbd21b24SSubash Abhinov Kasiviswanathan 128bbd21b24SSubash Abhinov Kasiviswanathan if (!csum_field) 129bbd21b24SSubash Abhinov Kasiviswanathan return -EPROTONOSUPPORT; 130bbd21b24SSubash Abhinov Kasiviswanathan 131bbd21b24SSubash Abhinov Kasiviswanathan csum_value = ~ntohs(csum_trailer->csum_value); 132bbd21b24SSubash Abhinov Kasiviswanathan ip6_hdr_csum = (__force __be16) 133bbd21b24SSubash Abhinov Kasiviswanathan ~ntohs((__force __be16)ip_compute_csum(ip6h, 134bbd21b24SSubash Abhinov Kasiviswanathan (int)(txporthdr - (void *)(skb->data)))); 135bbd21b24SSubash Abhinov Kasiviswanathan ip6_payload_csum = csum16_sub((__force __sum16)csum_value, 136bbd21b24SSubash Abhinov Kasiviswanathan ip6_hdr_csum); 137bbd21b24SSubash Abhinov Kasiviswanathan 138bbd21b24SSubash Abhinov Kasiviswanathan length = (ip6h->nexthdr == IPPROTO_UDP) ? 139bbd21b24SSubash Abhinov Kasiviswanathan ntohs(((struct udphdr *)txporthdr)->len) : 140bbd21b24SSubash Abhinov Kasiviswanathan ntohs(ip6h->payload_len); 141bbd21b24SSubash Abhinov Kasiviswanathan pseudo_csum = ~(csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 142bbd21b24SSubash Abhinov Kasiviswanathan length, ip6h->nexthdr, 0)); 143bbd21b24SSubash Abhinov Kasiviswanathan addend = (__force __be16)ntohs((__force __be16)pseudo_csum); 144bbd21b24SSubash Abhinov Kasiviswanathan pseudo_csum = csum16_add(ip6_payload_csum, addend); 145bbd21b24SSubash Abhinov Kasiviswanathan 146bbd21b24SSubash Abhinov Kasiviswanathan addend = (__force __be16)ntohs((__force __be16)*csum_field); 147bbd21b24SSubash Abhinov Kasiviswanathan csum_temp = ~csum16_sub(pseudo_csum, addend); 148bbd21b24SSubash Abhinov Kasiviswanathan csum_value_final = (__force u16)csum_temp; 149bbd21b24SSubash Abhinov Kasiviswanathan 150bbd21b24SSubash Abhinov Kasiviswanathan if (unlikely(csum_value_final == 0)) { 151bbd21b24SSubash Abhinov Kasiviswanathan switch (ip6h->nexthdr) { 152bbd21b24SSubash Abhinov Kasiviswanathan case IPPROTO_UDP: 153bbd21b24SSubash Abhinov Kasiviswanathan /* RFC 2460 section 8.1 154bbd21b24SSubash Abhinov Kasiviswanathan * DL6 One's complement rule for UDP checksum 0 155bbd21b24SSubash Abhinov Kasiviswanathan */ 156bbd21b24SSubash Abhinov Kasiviswanathan csum_value_final = ~csum_value_final; 157bbd21b24SSubash Abhinov Kasiviswanathan break; 158bbd21b24SSubash Abhinov Kasiviswanathan 159bbd21b24SSubash Abhinov Kasiviswanathan case IPPROTO_TCP: 160bbd21b24SSubash Abhinov Kasiviswanathan /* DL6 Non-RFC compliant TCP checksum found */ 161bbd21b24SSubash Abhinov Kasiviswanathan if (*csum_field == (__force __sum16)0xFFFF) 162bbd21b24SSubash Abhinov Kasiviswanathan csum_value_final = ~csum_value_final; 163bbd21b24SSubash Abhinov Kasiviswanathan break; 164bbd21b24SSubash Abhinov Kasiviswanathan } 165bbd21b24SSubash Abhinov Kasiviswanathan } 166bbd21b24SSubash Abhinov Kasiviswanathan 167bbd21b24SSubash Abhinov Kasiviswanathan if (csum_value_final == ntohs((__force __be16)*csum_field)) 168bbd21b24SSubash Abhinov Kasiviswanathan return 0; 169bbd21b24SSubash Abhinov Kasiviswanathan else 170bbd21b24SSubash Abhinov Kasiviswanathan return -EINVAL; 171bbd21b24SSubash Abhinov Kasiviswanathan } 172bbd21b24SSubash Abhinov Kasiviswanathan #endif 173bbd21b24SSubash Abhinov Kasiviswanathan 1745eb5f860SSubash Abhinov Kasiviswanathan static void rmnet_map_complement_ipv4_txporthdr_csum_field(void *iphdr) 1755eb5f860SSubash Abhinov Kasiviswanathan { 1765eb5f860SSubash Abhinov Kasiviswanathan struct iphdr *ip4h = (struct iphdr *)iphdr; 1775eb5f860SSubash Abhinov Kasiviswanathan void *txphdr; 1785eb5f860SSubash Abhinov Kasiviswanathan u16 *csum; 1795eb5f860SSubash Abhinov Kasiviswanathan 1805eb5f860SSubash Abhinov Kasiviswanathan txphdr = iphdr + ip4h->ihl * 4; 1815eb5f860SSubash Abhinov Kasiviswanathan 1825eb5f860SSubash Abhinov Kasiviswanathan if (ip4h->protocol == IPPROTO_TCP || ip4h->protocol == IPPROTO_UDP) { 1835eb5f860SSubash Abhinov Kasiviswanathan csum = (u16 *)rmnet_map_get_csum_field(ip4h->protocol, txphdr); 1845eb5f860SSubash Abhinov Kasiviswanathan *csum = ~(*csum); 1855eb5f860SSubash Abhinov Kasiviswanathan } 1865eb5f860SSubash Abhinov Kasiviswanathan } 1875eb5f860SSubash Abhinov Kasiviswanathan 1885eb5f860SSubash Abhinov Kasiviswanathan static void 1895eb5f860SSubash Abhinov Kasiviswanathan rmnet_map_ipv4_ul_csum_header(void *iphdr, 1905eb5f860SSubash Abhinov Kasiviswanathan struct rmnet_map_ul_csum_header *ul_header, 1915eb5f860SSubash Abhinov Kasiviswanathan struct sk_buff *skb) 1925eb5f860SSubash Abhinov Kasiviswanathan { 1935eb5f860SSubash Abhinov Kasiviswanathan struct iphdr *ip4h = (struct iphdr *)iphdr; 1945eb5f860SSubash Abhinov Kasiviswanathan __be16 *hdr = (__be16 *)ul_header, offset; 1955eb5f860SSubash Abhinov Kasiviswanathan 1965eb5f860SSubash Abhinov Kasiviswanathan offset = htons((__force u16)(skb_transport_header(skb) - 1975eb5f860SSubash Abhinov Kasiviswanathan (unsigned char *)iphdr)); 1985eb5f860SSubash Abhinov Kasiviswanathan ul_header->csum_start_offset = offset; 1995eb5f860SSubash Abhinov Kasiviswanathan ul_header->csum_insert_offset = skb->csum_offset; 2005eb5f860SSubash Abhinov Kasiviswanathan ul_header->csum_enabled = 1; 2015eb5f860SSubash Abhinov Kasiviswanathan if (ip4h->protocol == IPPROTO_UDP) 2025eb5f860SSubash Abhinov Kasiviswanathan ul_header->udp_ip4_ind = 1; 2035eb5f860SSubash Abhinov Kasiviswanathan else 2045eb5f860SSubash Abhinov Kasiviswanathan ul_header->udp_ip4_ind = 0; 2055eb5f860SSubash Abhinov Kasiviswanathan 2065eb5f860SSubash Abhinov Kasiviswanathan /* Changing remaining fields to network order */ 2075eb5f860SSubash Abhinov Kasiviswanathan hdr++; 2085eb5f860SSubash Abhinov Kasiviswanathan *hdr = htons((__force u16)*hdr); 2095eb5f860SSubash Abhinov Kasiviswanathan 2105eb5f860SSubash Abhinov Kasiviswanathan skb->ip_summed = CHECKSUM_NONE; 2115eb5f860SSubash Abhinov Kasiviswanathan 2125eb5f860SSubash Abhinov Kasiviswanathan rmnet_map_complement_ipv4_txporthdr_csum_field(iphdr); 2135eb5f860SSubash Abhinov Kasiviswanathan } 2145eb5f860SSubash Abhinov Kasiviswanathan 2155eb5f860SSubash Abhinov Kasiviswanathan #if IS_ENABLED(CONFIG_IPV6) 2165eb5f860SSubash Abhinov Kasiviswanathan static void rmnet_map_complement_ipv6_txporthdr_csum_field(void *ip6hdr) 2175eb5f860SSubash Abhinov Kasiviswanathan { 2185eb5f860SSubash Abhinov Kasiviswanathan struct ipv6hdr *ip6h = (struct ipv6hdr *)ip6hdr; 2195eb5f860SSubash Abhinov Kasiviswanathan void *txphdr; 2205eb5f860SSubash Abhinov Kasiviswanathan u16 *csum; 2215eb5f860SSubash Abhinov Kasiviswanathan 2225eb5f860SSubash Abhinov Kasiviswanathan txphdr = ip6hdr + sizeof(struct ipv6hdr); 2235eb5f860SSubash Abhinov Kasiviswanathan 2245eb5f860SSubash Abhinov Kasiviswanathan if (ip6h->nexthdr == IPPROTO_TCP || ip6h->nexthdr == IPPROTO_UDP) { 2255eb5f860SSubash Abhinov Kasiviswanathan csum = (u16 *)rmnet_map_get_csum_field(ip6h->nexthdr, txphdr); 2265eb5f860SSubash Abhinov Kasiviswanathan *csum = ~(*csum); 2275eb5f860SSubash Abhinov Kasiviswanathan } 2285eb5f860SSubash Abhinov Kasiviswanathan } 2295eb5f860SSubash Abhinov Kasiviswanathan 2305eb5f860SSubash Abhinov Kasiviswanathan static void 2315eb5f860SSubash Abhinov Kasiviswanathan rmnet_map_ipv6_ul_csum_header(void *ip6hdr, 2325eb5f860SSubash Abhinov Kasiviswanathan struct rmnet_map_ul_csum_header *ul_header, 2335eb5f860SSubash Abhinov Kasiviswanathan struct sk_buff *skb) 2345eb5f860SSubash Abhinov Kasiviswanathan { 2355eb5f860SSubash Abhinov Kasiviswanathan __be16 *hdr = (__be16 *)ul_header, offset; 2365eb5f860SSubash Abhinov Kasiviswanathan 2375eb5f860SSubash Abhinov Kasiviswanathan offset = htons((__force u16)(skb_transport_header(skb) - 2385eb5f860SSubash Abhinov Kasiviswanathan (unsigned char *)ip6hdr)); 2395eb5f860SSubash Abhinov Kasiviswanathan ul_header->csum_start_offset = offset; 2405eb5f860SSubash Abhinov Kasiviswanathan ul_header->csum_insert_offset = skb->csum_offset; 2415eb5f860SSubash Abhinov Kasiviswanathan ul_header->csum_enabled = 1; 2425eb5f860SSubash Abhinov Kasiviswanathan ul_header->udp_ip4_ind = 0; 2435eb5f860SSubash Abhinov Kasiviswanathan 2445eb5f860SSubash Abhinov Kasiviswanathan /* Changing remaining fields to network order */ 2455eb5f860SSubash Abhinov Kasiviswanathan hdr++; 2465eb5f860SSubash Abhinov Kasiviswanathan *hdr = htons((__force u16)*hdr); 2475eb5f860SSubash Abhinov Kasiviswanathan 2485eb5f860SSubash Abhinov Kasiviswanathan skb->ip_summed = CHECKSUM_NONE; 2495eb5f860SSubash Abhinov Kasiviswanathan 2505eb5f860SSubash Abhinov Kasiviswanathan rmnet_map_complement_ipv6_txporthdr_csum_field(ip6hdr); 2515eb5f860SSubash Abhinov Kasiviswanathan } 2525eb5f860SSubash Abhinov Kasiviswanathan #endif 2535eb5f860SSubash Abhinov Kasiviswanathan 254ceed73a2SSubash Abhinov Kasiviswanathan /* Adds MAP header to front of skb->data 255ceed73a2SSubash Abhinov Kasiviswanathan * Padding is calculated and set appropriately in MAP header. Mux ID is 256ceed73a2SSubash Abhinov Kasiviswanathan * initialized to 0. 257ceed73a2SSubash Abhinov Kasiviswanathan */ 258ceed73a2SSubash Abhinov Kasiviswanathan struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb, 259ceed73a2SSubash Abhinov Kasiviswanathan int hdrlen, int pad) 260ceed73a2SSubash Abhinov Kasiviswanathan { 261ceed73a2SSubash Abhinov Kasiviswanathan struct rmnet_map_header *map_header; 262ceed73a2SSubash Abhinov Kasiviswanathan u32 padding, map_datalen; 263ceed73a2SSubash Abhinov Kasiviswanathan u8 *padbytes; 264ceed73a2SSubash Abhinov Kasiviswanathan 265ceed73a2SSubash Abhinov Kasiviswanathan map_datalen = skb->len - hdrlen; 266ceed73a2SSubash Abhinov Kasiviswanathan map_header = (struct rmnet_map_header *) 267ceed73a2SSubash Abhinov Kasiviswanathan skb_push(skb, sizeof(struct rmnet_map_header)); 268ceed73a2SSubash Abhinov Kasiviswanathan memset(map_header, 0, sizeof(struct rmnet_map_header)); 269ceed73a2SSubash Abhinov Kasiviswanathan 270ceed73a2SSubash Abhinov Kasiviswanathan if (pad == RMNET_MAP_NO_PAD_BYTES) { 271ceed73a2SSubash Abhinov Kasiviswanathan map_header->pkt_len = htons(map_datalen); 272ceed73a2SSubash Abhinov Kasiviswanathan return map_header; 273ceed73a2SSubash Abhinov Kasiviswanathan } 274ceed73a2SSubash Abhinov Kasiviswanathan 275ceed73a2SSubash Abhinov Kasiviswanathan padding = ALIGN(map_datalen, 4) - map_datalen; 276ceed73a2SSubash Abhinov Kasiviswanathan 277ceed73a2SSubash Abhinov Kasiviswanathan if (padding == 0) 278ceed73a2SSubash Abhinov Kasiviswanathan goto done; 279ceed73a2SSubash Abhinov Kasiviswanathan 280ceed73a2SSubash Abhinov Kasiviswanathan if (skb_tailroom(skb) < padding) 281ceed73a2SSubash Abhinov Kasiviswanathan return NULL; 282ceed73a2SSubash Abhinov Kasiviswanathan 283ceed73a2SSubash Abhinov Kasiviswanathan padbytes = (u8 *)skb_put(skb, padding); 284ceed73a2SSubash Abhinov Kasiviswanathan memset(padbytes, 0, padding); 285ceed73a2SSubash Abhinov Kasiviswanathan 286ceed73a2SSubash Abhinov Kasiviswanathan done: 287ceed73a2SSubash Abhinov Kasiviswanathan map_header->pkt_len = htons(map_datalen + padding); 288ceed73a2SSubash Abhinov Kasiviswanathan map_header->pad_len = padding & 0x3F; 289ceed73a2SSubash Abhinov Kasiviswanathan 290ceed73a2SSubash Abhinov Kasiviswanathan return map_header; 291ceed73a2SSubash Abhinov Kasiviswanathan } 292ceed73a2SSubash Abhinov Kasiviswanathan 293ceed73a2SSubash Abhinov Kasiviswanathan /* Deaggregates a single packet 294ceed73a2SSubash Abhinov Kasiviswanathan * A whole new buffer is allocated for each portion of an aggregated frame. 295ceed73a2SSubash Abhinov Kasiviswanathan * Caller should keep calling deaggregate() on the source skb until 0 is 296ceed73a2SSubash Abhinov Kasiviswanathan * returned, indicating that there are no more packets to deaggregate. Caller 297ceed73a2SSubash Abhinov Kasiviswanathan * is responsible for freeing the original skb. 298ceed73a2SSubash Abhinov Kasiviswanathan */ 299bbd21b24SSubash Abhinov Kasiviswanathan struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb, 300bbd21b24SSubash Abhinov Kasiviswanathan struct rmnet_port *port) 301ceed73a2SSubash Abhinov Kasiviswanathan { 302ceed73a2SSubash Abhinov Kasiviswanathan struct rmnet_map_header *maph; 303ceed73a2SSubash Abhinov Kasiviswanathan struct sk_buff *skbn; 304ceed73a2SSubash Abhinov Kasiviswanathan u32 packet_len; 305ceed73a2SSubash Abhinov Kasiviswanathan 306ceed73a2SSubash Abhinov Kasiviswanathan if (skb->len == 0) 307ceed73a2SSubash Abhinov Kasiviswanathan return NULL; 308ceed73a2SSubash Abhinov Kasiviswanathan 309ceed73a2SSubash Abhinov Kasiviswanathan maph = (struct rmnet_map_header *)skb->data; 310ceed73a2SSubash Abhinov Kasiviswanathan packet_len = ntohs(maph->pkt_len) + sizeof(struct rmnet_map_header); 311ceed73a2SSubash Abhinov Kasiviswanathan 312bbd21b24SSubash Abhinov Kasiviswanathan if (port->data_format & RMNET_INGRESS_FORMAT_MAP_CKSUMV4) 313bbd21b24SSubash Abhinov Kasiviswanathan packet_len += sizeof(struct rmnet_map_dl_csum_trailer); 314bbd21b24SSubash Abhinov Kasiviswanathan 315ceed73a2SSubash Abhinov Kasiviswanathan if (((int)skb->len - (int)packet_len) < 0) 316ceed73a2SSubash Abhinov Kasiviswanathan return NULL; 317ceed73a2SSubash Abhinov Kasiviswanathan 3181f4f554aSDan Carpenter /* Some hardware can send us empty frames. Catch them */ 3191f4f554aSDan Carpenter if (ntohs(maph->pkt_len) == 0) 3201f4f554aSDan Carpenter return NULL; 3211f4f554aSDan Carpenter 322ceed73a2SSubash Abhinov Kasiviswanathan skbn = alloc_skb(packet_len + RMNET_MAP_DEAGGR_SPACING, GFP_ATOMIC); 323ceed73a2SSubash Abhinov Kasiviswanathan if (!skbn) 324ceed73a2SSubash Abhinov Kasiviswanathan return NULL; 325ceed73a2SSubash Abhinov Kasiviswanathan 326ceed73a2SSubash Abhinov Kasiviswanathan skbn->dev = skb->dev; 327ceed73a2SSubash Abhinov Kasiviswanathan skb_reserve(skbn, RMNET_MAP_DEAGGR_HEADROOM); 328ceed73a2SSubash Abhinov Kasiviswanathan skb_put(skbn, packet_len); 329ceed73a2SSubash Abhinov Kasiviswanathan memcpy(skbn->data, skb->data, packet_len); 330ceed73a2SSubash Abhinov Kasiviswanathan skb_pull(skb, packet_len); 331ceed73a2SSubash Abhinov Kasiviswanathan 332ceed73a2SSubash Abhinov Kasiviswanathan return skbn; 333ceed73a2SSubash Abhinov Kasiviswanathan } 334bbd21b24SSubash Abhinov Kasiviswanathan 335bbd21b24SSubash Abhinov Kasiviswanathan /* Validates packet checksums. Function takes a pointer to 336bbd21b24SSubash Abhinov Kasiviswanathan * the beginning of a buffer which contains the IP payload + 337bbd21b24SSubash Abhinov Kasiviswanathan * padding + checksum trailer. 338bbd21b24SSubash Abhinov Kasiviswanathan * Only IPv4 and IPv6 are supported along with TCP & UDP. 339bbd21b24SSubash Abhinov Kasiviswanathan * Fragmented or tunneled packets are not supported. 340bbd21b24SSubash Abhinov Kasiviswanathan */ 341bbd21b24SSubash Abhinov Kasiviswanathan int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len) 342bbd21b24SSubash Abhinov Kasiviswanathan { 343bbd21b24SSubash Abhinov Kasiviswanathan struct rmnet_map_dl_csum_trailer *csum_trailer; 344bbd21b24SSubash Abhinov Kasiviswanathan 345bbd21b24SSubash Abhinov Kasiviswanathan if (unlikely(!(skb->dev->features & NETIF_F_RXCSUM))) 346bbd21b24SSubash Abhinov Kasiviswanathan return -EOPNOTSUPP; 347bbd21b24SSubash Abhinov Kasiviswanathan 348bbd21b24SSubash Abhinov Kasiviswanathan csum_trailer = (struct rmnet_map_dl_csum_trailer *)(skb->data + len); 349bbd21b24SSubash Abhinov Kasiviswanathan 350bbd21b24SSubash Abhinov Kasiviswanathan if (!csum_trailer->valid) 351bbd21b24SSubash Abhinov Kasiviswanathan return -EINVAL; 352bbd21b24SSubash Abhinov Kasiviswanathan 353bbd21b24SSubash Abhinov Kasiviswanathan if (skb->protocol == htons(ETH_P_IP)) 354bbd21b24SSubash Abhinov Kasiviswanathan return rmnet_map_ipv4_dl_csum_trailer(skb, csum_trailer); 355bbd21b24SSubash Abhinov Kasiviswanathan else if (skb->protocol == htons(ETH_P_IPV6)) 356bbd21b24SSubash Abhinov Kasiviswanathan #if IS_ENABLED(CONFIG_IPV6) 357bbd21b24SSubash Abhinov Kasiviswanathan return rmnet_map_ipv6_dl_csum_trailer(skb, csum_trailer); 358bbd21b24SSubash Abhinov Kasiviswanathan #else 359bbd21b24SSubash Abhinov Kasiviswanathan return -EPROTONOSUPPORT; 360bbd21b24SSubash Abhinov Kasiviswanathan #endif 361bbd21b24SSubash Abhinov Kasiviswanathan 362bbd21b24SSubash Abhinov Kasiviswanathan return 0; 363bbd21b24SSubash Abhinov Kasiviswanathan } 3645eb5f860SSubash Abhinov Kasiviswanathan 3655eb5f860SSubash Abhinov Kasiviswanathan /* Generates UL checksum meta info header for IPv4 and IPv6 over TCP and UDP 3665eb5f860SSubash Abhinov Kasiviswanathan * packets that are supported for UL checksum offload. 3675eb5f860SSubash Abhinov Kasiviswanathan */ 3685eb5f860SSubash Abhinov Kasiviswanathan void rmnet_map_checksum_uplink_packet(struct sk_buff *skb, 3695eb5f860SSubash Abhinov Kasiviswanathan struct net_device *orig_dev) 3705eb5f860SSubash Abhinov Kasiviswanathan { 3715eb5f860SSubash Abhinov Kasiviswanathan struct rmnet_map_ul_csum_header *ul_header; 3725eb5f860SSubash Abhinov Kasiviswanathan void *iphdr; 3735eb5f860SSubash Abhinov Kasiviswanathan 3745eb5f860SSubash Abhinov Kasiviswanathan ul_header = (struct rmnet_map_ul_csum_header *) 3755eb5f860SSubash Abhinov Kasiviswanathan skb_push(skb, sizeof(struct rmnet_map_ul_csum_header)); 3765eb5f860SSubash Abhinov Kasiviswanathan 3775eb5f860SSubash Abhinov Kasiviswanathan if (unlikely(!(orig_dev->features & 3785eb5f860SSubash Abhinov Kasiviswanathan (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)))) 3795eb5f860SSubash Abhinov Kasiviswanathan goto sw_csum; 3805eb5f860SSubash Abhinov Kasiviswanathan 3815eb5f860SSubash Abhinov Kasiviswanathan if (skb->ip_summed == CHECKSUM_PARTIAL) { 3825eb5f860SSubash Abhinov Kasiviswanathan iphdr = (char *)ul_header + 3835eb5f860SSubash Abhinov Kasiviswanathan sizeof(struct rmnet_map_ul_csum_header); 3845eb5f860SSubash Abhinov Kasiviswanathan 3855eb5f860SSubash Abhinov Kasiviswanathan if (skb->protocol == htons(ETH_P_IP)) { 3865eb5f860SSubash Abhinov Kasiviswanathan rmnet_map_ipv4_ul_csum_header(iphdr, ul_header, skb); 3875eb5f860SSubash Abhinov Kasiviswanathan return; 3885eb5f860SSubash Abhinov Kasiviswanathan } else if (skb->protocol == htons(ETH_P_IPV6)) { 3895eb5f860SSubash Abhinov Kasiviswanathan #if IS_ENABLED(CONFIG_IPV6) 3905eb5f860SSubash Abhinov Kasiviswanathan rmnet_map_ipv6_ul_csum_header(iphdr, ul_header, skb); 3915eb5f860SSubash Abhinov Kasiviswanathan return; 3925eb5f860SSubash Abhinov Kasiviswanathan #else 3935eb5f860SSubash Abhinov Kasiviswanathan goto sw_csum; 3945eb5f860SSubash Abhinov Kasiviswanathan #endif 3955eb5f860SSubash Abhinov Kasiviswanathan } 3965eb5f860SSubash Abhinov Kasiviswanathan } 3975eb5f860SSubash Abhinov Kasiviswanathan 3985eb5f860SSubash Abhinov Kasiviswanathan sw_csum: 3995eb5f860SSubash Abhinov Kasiviswanathan ul_header->csum_start_offset = 0; 4005eb5f860SSubash Abhinov Kasiviswanathan ul_header->csum_insert_offset = 0; 4015eb5f860SSubash Abhinov Kasiviswanathan ul_header->csum_enabled = 0; 4025eb5f860SSubash Abhinov Kasiviswanathan ul_header->udp_ip4_ind = 0; 4035eb5f860SSubash Abhinov Kasiviswanathan } 404