kernel/drivers/net/myri10ge/myri10ge_lro.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2007-2009 Myricom, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #include "myri10ge_var.h"
  28
  29 #define IP_OFFMASK 0x1fff
  30 #define TCPOPT_TIMESTAMP 8
  31 #define TCPOLEN_TIMESTAMP 10
  32 #define TCPOLEN_TSTAMP_APPA 12
  33
  34
  35 /*
  36  * Assume len is a multiple of 4. Note that "raw" must be
  37  * suitably aligned. In practice, it will always enter algned on
  38  * at least a 4 bytes bounday, due to the alignment of our rx buffers.
  39  */
  40 uint16_t
  41 myri10ge_csum_generic(uint16_t *raw, int len)
  42 {
  43         uint32_t csum;
  44         csum = 0;
  45         while (len > 0) {
  46                 csum += *raw;
  47                 raw++;
  48                 csum += *raw;
  49                 raw++;
  50                 len -= 4;
  51         }
  52         csum = (csum >> 16) + (csum & 0xffff);
  53         csum = (csum >> 16) + (csum & 0xffff);
  54         return ((uint16_t)csum);
  55 }
  56
  57 static uint16_t
  58 myri10ge_in_pseudo(unsigned int a, unsigned int b,
  59     unsigned int c)
  60 {
  61         uint64_t csum;
  62
  63         csum = (uint64_t)a + b + c;
  64         csum = (csum >> 16) + (csum & 0xffff);
  65         csum = (csum >> 16) + (csum & 0xffff);
  66         return ((uint16_t)csum);
  67 }
  68
  69 void
  70 myri10ge_lro_flush(struct myri10ge_slice_state *ss, struct lro_entry *lro,
  71     struct myri10ge_mblk_list *mbl)
  72 {
  73         struct ip *ip;
  74         struct tcphdr *tcp;
  75         uint32_t *ts_ptr;
  76         uint32_t tcplen, tcp_csum;
  77
  78         if (lro->append_cnt) {
  79                 /*
  80                  * incorporate the new len into the ip header and
  81                  * re-calculate the checksum
  82                  */
  83                 ip = lro->ip;
  84                 ip->ip_len = htons(lro->len - ETHERNET_HEADER_SIZE);
  85                 ip->ip_sum = 0;
  86                 ip->ip_sum = 0xffff ^
  87                     myri10ge_csum_generic((uint16_t *)ip, sizeof (*ip));
  88                 /* incorporate the latest ack into the tcp header */
  89                 tcp = (struct tcphdr *)(ip + 1);
  90                 tcp->th_ack = lro->ack_seq;
  91                 tcp->th_win = lro->window;
  92                 tcp->th_flags = lro->flags;
  93                 /* incorporate latest timestamp into the tcp header */
  94                 if (lro->timestamp) {
  95                         ts_ptr = (uint32_t *)(tcp + 1);
  96                         ts_ptr[1] = htonl(lro->tsval);
  97                         ts_ptr[2] = lro->tsecr;
  98                 }
  99                 /*
 100                  * update checksum in tcp header by re-calculating the
 101                  * tcp pseudoheader checksum, and adding it to the checksum
 102                  * of the tcp payload data
 103                  */
 104                 tcp->th_sum = 0;
 105                 tcplen = lro->len - sizeof (*ip) - ETHERNET_HEADER_SIZE;
 106                 tcp_csum = lro->data_csum;
 107                 tcp_csum += myri10ge_in_pseudo(ip->ip_src.s_addr,
 108                     ip->ip_dst.s_addr, htons(tcplen + IPPROTO_TCP));
 109                 tcp_csum += myri10ge_csum_generic((uint16_t *)tcp,
 110                     tcp->th_off << 2);
 111                 tcp_csum = (tcp_csum & 0xffff) + (tcp_csum >> 16);
 112                 tcp_csum = (tcp_csum & 0xffff) + (tcp_csum >> 16);
 113                 tcp->th_sum = 0xffff ^ tcp_csum;
 114         }
 115
 116         mac_hcksum_set(lro->m_head, 0, 0, 0,
 117             0, HCK_IPV4_HDRCKSUM_OK | HCK_FULLCKSUM_OK);
 118
 119         mbl->cnt += lro->append_cnt;
 120         myri10ge_mbl_append(ss, mbl, lro->m_head);
 121         MYRI10GE_SLICE_STAT_INC(lro_flushed);
 122         MYRI10GE_SLICE_STAT_ADD(lro_queued, lro->append_cnt + 1);
 123         lro->m_head = NULL;
 124         lro->timestamp = 0;
 125         lro->append_cnt = 0;
 126         lro->next = ss->lro_free;
 127         ss->lro_free = lro;
 128 }
 129
 130 int
 131 myri10ge_lro_rx(struct myri10ge_slice_state *ss, mblk_t *m_head,
 132     uint32_t csum, struct myri10ge_mblk_list *mbl)
 133 {
 134         struct ether_header *eh;
 135         struct ip *ip;
 136         struct tcphdr *tcp;
 137         uint32_t *ts_ptr;
 138         struct lro_entry *lro, *curr;
 139         int hlen, ip_len, tcp_hdr_len, tcp_data_len;
 140         int opt_bytes, trim;
 141         int tot_len = MBLKL(m_head);
 142         uint32_t seq, tmp_csum;
 143
 144         eh = (struct ether_header *)(void *)m_head->b_rptr;
 145         if (eh->ether_type != htons(ETHERTYPE_IP))
 146                 return (EINVAL);
 147         ip = (struct ip *)(void *)(eh + 1);
 148         if (ip->ip_p != IPPROTO_TCP)
 149                 return (EINVAL);
 150
 151         /* ensure there are no options */
 152         if ((ip->ip_hl << 2) != sizeof (*ip))
 153                 return (EINVAL);
 154
 155         /* .. and the packet is not fragmented */
 156         if (ip->ip_off & htons(IP_MF|IP_OFFMASK))
 157                 return (EINVAL);
 158
 159         /* verify that the IP header checksum is correct */
 160         tmp_csum = myri10ge_csum_generic((uint16_t *)ip, sizeof (*ip));
 161         if (unlikely((tmp_csum ^ 0xffff) != 0)) {
 162                 MYRI10GE_SLICE_STAT_INC(lro_bad_csum);
 163                 return (EINVAL);
 164         }
 165
 166         /* find the TCP header */
 167         tcp = (struct tcphdr *)(ip + 1);
 168
 169         /* ensure no bits set besides ack or psh */
 170         if ((tcp->th_flags & ~(TH_ACK | TH_PUSH)) != 0)
 171                 return (EINVAL);
 172
 173         /*
 174          * check for timestamps. Since the only option we handle are
 175          * timestamps, we only have to handle the simple case of
 176          * aligned timestamps
 177          */
 178
 179         opt_bytes = (tcp->th_off << 2) - sizeof (*tcp);
 180         tcp_hdr_len =  sizeof (*tcp) + opt_bytes;
 181         ts_ptr = (uint32_t *)(tcp + 1);
 182         if (opt_bytes != 0) {
 183                 if (unlikely(opt_bytes != TCPOLEN_TSTAMP_APPA) ||
 184                     (*ts_ptr !=  ntohl(TCPOPT_NOP<<24|TCPOPT_NOP<<16|
 185                     TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)))
 186                         return (EINVAL);
 187         }
 188
 189         ip_len = ntohs(ip->ip_len);
 190         tcp_data_len = ip_len - (tcp->th_off << 2) - sizeof (*ip);
 191
 192         /*
 193          * If frame is padded beyond the end of the IP packet,
 194          * then we must trim the extra bytes off the end.
 195          */
 196         trim = tot_len - (ip_len + ETHERNET_HEADER_SIZE);
 197         if (trim != 0) {
 198                 if (trim < 0) {
 199                         /* truncated packet */
 200                         return (EINVAL);
 201                 }
 202                 m_head->b_wptr -= trim;
 203                 tot_len -= trim;
 204         }
 205
 206         /* Verify TCP checksum */
 207         csum = ntohs((uint16_t)csum);
 208         tmp_csum = csum + myri10ge_in_pseudo(ip->ip_src.s_addr,
 209             ip->ip_dst.s_addr, htons(tcp_hdr_len + tcp_data_len + IPPROTO_TCP));
 210         tmp_csum = (tmp_csum & 0xffff) + (tmp_csum >> 16);
 211         tmp_csum = (tmp_csum & 0xffff) + (tmp_csum >> 16);
 212         if (tmp_csum != 0xffff) {
 213                 MYRI10GE_SLICE_STAT_INC(lro_bad_csum);
 214                 return (EINVAL);
 215         }
 216
 217         hlen = ip_len + ETHERNET_HEADER_SIZE - tcp_data_len;
 218         seq = ntohl(tcp->th_seq);
 219
 220         for (lro = ss->lro_active; lro != NULL; lro = lro->next) {
 221                 if (lro->source_port == tcp->th_sport &&
 222                     lro->dest_port == tcp->th_dport &&
 223                     lro->source_ip == ip->ip_src.s_addr &&
 224                     lro->dest_ip == ip->ip_dst.s_addr) {
 225                         /* Try to append it */
 226
 227                         if (unlikely(seq != lro->next_seq)) {
 228                                 /* out of order packet */
 229                                 if (ss->lro_active == lro) {
 230                                         ss->lro_active = lro->next;
 231                                 } else {
 232                                         curr = ss->lro_active;
 233                                         while (curr->next != lro)
 234                                                 curr = curr->next;
 235                                         curr->next = lro->next;
 236                                 }
 237                                 myri10ge_lro_flush(ss, lro, mbl);
 238                                 return (EINVAL);
 239                         }
 240
 241                         if (opt_bytes) {
 242                                 uint32_t tsval = ntohl(*(ts_ptr + 1));
 243                                 /* make sure timestamp values are increasing */
 244                                 if (unlikely(lro->tsval > tsval ||
 245                                     *(ts_ptr + 2) == 0)) {
 246                                         return (-8);
 247                                 }
 248                                 lro->tsval = tsval;
 249                                 lro->tsecr = *(ts_ptr + 2);
 250                         }
 251
 252                         lro->next_seq += tcp_data_len;
 253                         lro->ack_seq = tcp->th_ack;
 254                         lro->window = tcp->th_win;
 255                         lro->flags |= tcp->th_flags;
 256                         lro->append_cnt++;
 257                         if (tcp_data_len == 0) {
 258                                 freeb(m_head);
 259                                 return (0);
 260                         }
 261                         /*
 262                          * subtract off the checksum of the tcp header
 263                          * from the hardware checksum, and add it to
 264                          * the stored tcp data checksum.  Byteswap
 265                          * the checksum if the total length so far is
 266                          * odd
 267                          */
 268                         tmp_csum = myri10ge_csum_generic((uint16_t *)tcp,
 269                             tcp_hdr_len);
 270                         csum = csum + (tmp_csum ^ 0xffff);
 271                         csum = (csum & 0xffff) + (csum >> 16);
 272                         csum = (csum & 0xffff) + (csum >> 16);
 273                         if (lro->len & 0x1) {
 274                                 /* Odd number of bytes so far, flip bytes */
 275                                 csum = ((csum << 8) | (csum >> 8)) & 0xffff;
 276                         }
 277                         csum = csum + lro->data_csum;
 278                         csum = (csum & 0xffff) + (csum >> 16);
 279                         csum = (csum & 0xffff) + (csum >> 16);
 280                         lro->data_csum = csum;
 281
 282                         lro->len += tcp_data_len;
 283
 284                         /*
 285                          * adjust mblk so that rptr points to
 286                          * the first byte of the payload
 287                          */
 288                         m_head->b_rptr += hlen;
 289                         /* append mbuf chain */
 290                         lro->m_tail->b_cont = m_head;
 291                         /* advance the last pointer */
 292                         lro->m_tail = m_head;
 293                         /* flush packet if required */
 294                         if (lro->len > (65535 - myri10ge_mtu) ||
 295                             (lro->append_cnt + 1) == myri10ge_lro_max_aggr) {
 296                                 if (ss->lro_active == lro) {
 297                                         ss->lro_active = lro->next;
 298                                 } else {
 299                                         curr = ss->lro_active;
 300                                         while (curr->next != lro)
 301                                                 curr = curr->next;
 302                                         curr->next = lro->next;
 303                                 }
 304                                 myri10ge_lro_flush(ss, lro, mbl);
 305                         }
 306                         return (0);
 307                 }
 308         }
 309
 310         if (ss->lro_free == NULL)
 311                 return (ENOMEM);
 312
 313         /* start a new chain */
 314         lro = ss->lro_free;
 315         ss->lro_free = lro->next;
 316         lro->next = ss->lro_active;
 317         ss->lro_active = lro;
 318         lro->source_port = tcp->th_sport;
 319         lro->dest_port = tcp->th_dport;
 320         lro->source_ip = ip->ip_src.s_addr;
 321         lro->dest_ip = ip->ip_dst.s_addr;
 322         lro->next_seq = seq + tcp_data_len;
 323         lro->mss = (uint16_t)tcp_data_len;
 324         lro->ack_seq = tcp->th_ack;
 325         lro->window = tcp->th_win;
 326         lro->flags = tcp->th_flags;
 327
 328         /*
 329          * save the checksum of just the TCP payload by
 330          * subtracting off the checksum of the TCP header from
 331          * the entire hardware checksum
 332          * Since IP header checksum is correct, checksum over
 333          * the IP header is -0.  Substracting -0 is unnecessary.
 334          */
 335         tmp_csum = myri10ge_csum_generic((uint16_t *)tcp, tcp_hdr_len);
 336         csum = csum + (tmp_csum ^ 0xffff);
 337         csum = (csum & 0xffff) + (csum >> 16);
 338         csum = (csum & 0xffff) + (csum >> 16);
 339         lro->data_csum = csum;
 340         lro->ip = ip;
 341
 342         /* record timestamp if it is present */
 343         if (opt_bytes) {
 344                 lro->timestamp = 1;
 345                 lro->tsval = ntohl(*(ts_ptr + 1));
 346                 lro->tsecr = *(ts_ptr + 2);
 347         }
 348         lro->len = tot_len;
 349         lro->m_head = m_head;
 350         lro->m_tail = m_head;
 351         return (0);
 352 }
 353
 354 /*
 355  *  This file uses MyriGE driver indentation.
 356  *
 357  * Local Variables:
 358  * c-file-style:"sun"
 359  * tab-width:8
 360  * End:
 361  */