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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 | /* * linux/net/ipv4/inet_lro.c * * Large Receive Offload (ipv4 / tcp) * * (C) Copyright IBM Corp. 2007 * * Authors: * Jan-Bernd Themann <themann@de.ibm.com> * Christoph Raisch <raisch@de.ibm.com> * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/module.h> #include <linux/if_vlan.h> #include <linux/inet_lro.h> #include <net/checksum.h> MODULE_LICENSE("GPL"); MODULE_AUTHOR("Jan-Bernd Themann <themann@de.ibm.com>"); MODULE_DESCRIPTION("Large Receive Offload (ipv4 / tcp)"); #define TCP_HDR_LEN(tcph) (tcph->doff << 2) #define IP_HDR_LEN(iph) (iph->ihl << 2) #define TCP_PAYLOAD_LENGTH(iph, tcph) \ (ntohs(iph->tot_len) - IP_HDR_LEN(iph) - TCP_HDR_LEN(tcph)) #define IPH_LEN_WO_OPTIONS 5 #define TCPH_LEN_WO_OPTIONS 5 #define TCPH_LEN_W_TIMESTAMP 8 #define LRO_MAX_PG_HLEN 64 #define LRO_INC_STATS(lro_mgr, attr) { lro_mgr->stats.attr++; } /* * Basic tcp checks whether packet is suitable for LRO */ static int lro_tcp_ip_check(const struct iphdr *iph, const struct tcphdr *tcph, int len, const struct net_lro_desc *lro_desc) { /* check ip header: don't aggregate padded frames */ if (ntohs(iph->tot_len) != len) return -1; if (TCP_PAYLOAD_LENGTH(iph, tcph) == 0) return -1; if (iph->ihl != IPH_LEN_WO_OPTIONS) return -1; if (tcph->cwr || tcph->ece || tcph->urg || !tcph->ack || tcph->rst || tcph->syn || tcph->fin) return -1; if (INET_ECN_is_ce(ipv4_get_dsfield(iph))) return -1; if (tcph->doff != TCPH_LEN_WO_OPTIONS && tcph->doff != TCPH_LEN_W_TIMESTAMP) return -1; /* check tcp options (only timestamp allowed) */ if (tcph->doff == TCPH_LEN_W_TIMESTAMP) { __be32 *topt = (__be32 *)(tcph + 1); if (*topt != htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)) return -1; /* timestamp should be in right order */ topt++; if (lro_desc && after(ntohl(lro_desc->tcp_rcv_tsval), ntohl(*topt))) return -1; /* timestamp reply should not be zero */ topt++; if (*topt == 0) return -1; } return 0; } static void lro_update_tcp_ip_header(struct net_lro_desc *lro_desc) { struct iphdr *iph = lro_desc->iph; struct tcphdr *tcph = lro_desc->tcph; __be32 *p; __wsum tcp_hdr_csum; tcph->ack_seq = lro_desc->tcp_ack; tcph->window = lro_desc->tcp_window; if (lro_desc->tcp_saw_tstamp) { p = (__be32 *)(tcph + 1); *(p+2) = lro_desc->tcp_rcv_tsecr; } csum_replace2(&iph->check, iph->tot_len, htons(lro_desc->ip_tot_len)); iph->tot_len = htons(lro_desc->ip_tot_len); tcph->check = 0; tcp_hdr_csum = csum_partial(tcph, TCP_HDR_LEN(tcph), 0); lro_desc->data_csum = csum_add(lro_desc->data_csum, tcp_hdr_csum); tcph->check = csum_tcpudp_magic(iph->saddr, iph->daddr, lro_desc->ip_tot_len - IP_HDR_LEN(iph), IPPROTO_TCP, lro_desc->data_csum); } static __wsum lro_tcp_data_csum(struct iphdr *iph, struct tcphdr *tcph, int len) { __wsum tcp_csum; __wsum tcp_hdr_csum; __wsum tcp_ps_hdr_csum; tcp_csum = ~csum_unfold(tcph->check); tcp_hdr_csum = csum_partial(tcph, TCP_HDR_LEN(tcph), tcp_csum); tcp_ps_hdr_csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, len + TCP_HDR_LEN(tcph), IPPROTO_TCP, 0); return csum_sub(csum_sub(tcp_csum, tcp_hdr_csum), tcp_ps_hdr_csum); } static void lro_init_desc(struct net_lro_desc *lro_desc, struct sk_buff *skb, struct iphdr *iph, struct tcphdr *tcph) { int nr_frags; __be32 *ptr; u32 tcp_data_len = TCP_PAYLOAD_LENGTH(iph, tcph); nr_frags = skb_shinfo(skb)->nr_frags; lro_desc->parent = skb; lro_desc->next_frag = &(skb_shinfo(skb)->frags[nr_frags]); lro_desc->iph = iph; lro_desc->tcph = tcph; lro_desc->tcp_next_seq = ntohl(tcph->seq) + tcp_data_len; lro_desc->tcp_ack = tcph->ack_seq; lro_desc->tcp_window = tcph->window; lro_desc->pkt_aggr_cnt = 1; lro_desc->ip_tot_len = ntohs(iph->tot_len); if (tcph->doff == 8) { ptr = (__be32 *)(tcph+1); lro_desc->tcp_saw_tstamp = 1; lro_desc->tcp_rcv_tsval = *(ptr+1); lro_desc->tcp_rcv_tsecr = *(ptr+2); } lro_desc->mss = tcp_data_len; lro_desc->active = 1; lro_desc->data_csum = lro_tcp_data_csum(iph, tcph, tcp_data_len); } static inline void lro_clear_desc(struct net_lro_desc *lro_desc) { memset(lro_desc, 0, sizeof(struct net_lro_desc)); } static void lro_add_common(struct net_lro_desc *lro_desc, struct iphdr *iph, struct tcphdr *tcph, int tcp_data_len) { struct sk_buff *parent = lro_desc->parent; __be32 *topt; lro_desc->pkt_aggr_cnt++; lro_desc->ip_tot_len += tcp_data_len; lro_desc->tcp_next_seq += tcp_data_len; lro_desc->tcp_window = tcph->window; lro_desc->tcp_ack = tcph->ack_seq; /* don't update tcp_rcv_tsval, would not work with PAWS */ if (lro_desc->tcp_saw_tstamp) { topt = (__be32 *) (tcph + 1); lro_desc->tcp_rcv_tsecr = *(topt + 2); } lro_desc->data_csum = csum_block_add(lro_desc->data_csum, lro_tcp_data_csum(iph, tcph, tcp_data_len), parent->len); parent->len += tcp_data_len; parent->data_len += tcp_data_len; if (tcp_data_len > lro_desc->mss) lro_desc->mss = tcp_data_len; } static void lro_add_packet(struct net_lro_desc *lro_desc, struct sk_buff *skb, struct iphdr *iph, struct tcphdr *tcph) { struct sk_buff *parent = lro_desc->parent; int tcp_data_len = TCP_PAYLOAD_LENGTH(iph, tcph); lro_add_common(lro_desc, iph, tcph, tcp_data_len); skb_pull(skb, (skb->len - tcp_data_len)); parent->truesize += skb->truesize; if (lro_desc->last_skb) lro_desc->last_skb->next = skb; else skb_shinfo(parent)->frag_list = skb; lro_desc->last_skb = skb; } static int lro_check_tcp_conn(struct net_lro_desc *lro_desc, struct iphdr *iph, struct tcphdr *tcph) { if ((lro_desc->iph->saddr != iph->saddr) || (lro_desc->iph->daddr != iph->daddr) || (lro_desc->tcph->source != tcph->source) || (lro_desc->tcph->dest != tcph->dest)) return -1; return 0; } static struct net_lro_desc *lro_get_desc(struct net_lro_mgr *lro_mgr, struct net_lro_desc *lro_arr, struct iphdr *iph, struct tcphdr *tcph) { struct net_lro_desc *lro_desc = NULL; struct net_lro_desc *tmp; int max_desc = lro_mgr->max_desc; int i; for (i = 0; i < max_desc; i++) { tmp = &lro_arr[i]; if (tmp->active) if (!lro_check_tcp_conn(tmp, iph, tcph)) { lro_desc = tmp; goto out; } } for (i = 0; i < max_desc; i++) { if (!lro_arr[i].active) { lro_desc = &lro_arr[i]; goto out; } } LRO_INC_STATS(lro_mgr, no_desc); out: return lro_desc; } static void lro_flush(struct net_lro_mgr *lro_mgr, struct net_lro_desc *lro_desc) { if (lro_desc->pkt_aggr_cnt > 1) lro_update_tcp_ip_header(lro_desc); skb_shinfo(lro_desc->parent)->gso_size = lro_desc->mss; if (lro_mgr->features & LRO_F_NAPI) netif_receive_skb(lro_desc->parent); else netif_rx(lro_desc->parent); LRO_INC_STATS(lro_mgr, flushed); lro_clear_desc(lro_desc); } static int __lro_proc_skb(struct net_lro_mgr *lro_mgr, struct sk_buff *skb, void *priv) { struct net_lro_desc *lro_desc; struct iphdr *iph; struct tcphdr *tcph; u64 flags; int vlan_hdr_len = 0; if (!lro_mgr->get_skb_header || lro_mgr->get_skb_header(skb, (void *)&iph, (void *)&tcph, &flags, priv)) goto out; if (!(flags & LRO_IPV4) || !(flags & LRO_TCP)) goto out; lro_desc = lro_get_desc(lro_mgr, lro_mgr->lro_arr, iph, tcph); if (!lro_desc) goto out; if ((skb->protocol == htons(ETH_P_8021Q)) && !(lro_mgr->features & LRO_F_EXTRACT_VLAN_ID)) vlan_hdr_len = VLAN_HLEN; if (!lro_desc->active) { /* start new lro session */ if (lro_tcp_ip_check(iph, tcph, skb->len - vlan_hdr_len, NULL)) goto out; skb->ip_summed = lro_mgr->ip_summed_aggr; lro_init_desc(lro_desc, skb, iph, tcph); LRO_INC_STATS(lro_mgr, aggregated); return 0; } if (lro_desc->tcp_next_seq != ntohl(tcph->seq)) goto out2; if (lro_tcp_ip_check(iph, tcph, skb->len, lro_desc)) goto out2; lro_add_packet(lro_desc, skb, iph, tcph); LRO_INC_STATS(lro_mgr, aggregated); if ((lro_desc->pkt_aggr_cnt >= lro_mgr->max_aggr) || lro_desc->parent->len > (0xFFFF - lro_mgr->dev->mtu)) lro_flush(lro_mgr, lro_desc); return 0; out2: /* send aggregated SKBs to stack */ lro_flush(lro_mgr, lro_desc); out: return 1; } void lro_receive_skb(struct net_lro_mgr *lro_mgr, struct sk_buff *skb, void *priv) { if (__lro_proc_skb(lro_mgr, skb, priv)) { if (lro_mgr->features & LRO_F_NAPI) netif_receive_skb(skb); else netif_rx(skb); } } EXPORT_SYMBOL(lro_receive_skb); void lro_flush_all(struct net_lro_mgr *lro_mgr) { int i; struct net_lro_desc *lro_desc = lro_mgr->lro_arr; for (i = 0; i < lro_mgr->max_desc; i++) { if (lro_desc[i].active) lro_flush(lro_mgr, &lro_desc[i]); } } EXPORT_SYMBOL(lro_flush_all); |