include/net/gro.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 #ifndef _NET_IPV6_GRO_H
   4 #define _NET_IPV6_GRO_H
   5
   6 #include <linux/indirect_call_wrapper.h>
   7 #include <linux/ip.h>
   8 #include <linux/ipv6.h>
   9 #include <net/ip6_checksum.h>
  10 #include <linux/skbuff.h>
  11 #include <net/udp.h>
  12
  13 struct napi_gro_cb {
  14         /* Virtual address of skb_shinfo(skb)->frags[0].page + offset. */
  15         void    *frag0;
  16
  17         /* Length of frag0. */
  18         unsigned int frag0_len;
  19
  20         /* This indicates where we are processing relative to skb->data. */
  21         int     data_offset;
  22
  23         /* This is non-zero if the packet cannot be merged with the new skb. */
  24         u16     flush;
  25
  26         /* Save the IP ID here and check when we get to the transport layer */
  27         u16     flush_id;
  28
  29         /* Number of segments aggregated. */
  30         u16     count;
  31
  32         /* Used in ipv6_gro_receive() and foo-over-udp */
  33         u16     proto;
  34
  35         /* jiffies when first packet was created/queued */
  36         unsigned long age;
  37
  38 /* Used in napi_gro_cb::free */
  39 #define NAPI_GRO_FREE             1
  40 #define NAPI_GRO_FREE_STOLEN_HEAD 2
  41         /* portion of the cb set to zero at every gro iteration */
  42         struct_group(zeroed,
  43
  44                 /* Start offset for remote checksum offload */
  45                 u16     gro_remcsum_start;
  46
  47                 /* This is non-zero if the packet may be of the same flow. */
  48                 u8      same_flow:1;
  49
  50                 /* Used in tunnel GRO receive */
  51                 u8      encap_mark:1;
  52
  53                 /* GRO checksum is valid */
  54                 u8      csum_valid:1;
  55
  56                 /* Number of checksums via CHECKSUM_UNNECESSARY */
  57                 u8      csum_cnt:3;
  58
  59                 /* Free the skb? */
  60                 u8      free:2;
  61
  62                 /* Used in foo-over-udp, set in udp[46]_gro_receive */
  63                 u8      is_ipv6:1;
  64
  65                 /* Used in GRE, set in fou/gue_gro_receive */
  66                 u8      is_fou:1;
  67
  68                 /* Used to determine if flush_id can be ignored */
  69                 u8      is_atomic:1;
  70
  71                 /* Number of gro_receive callbacks this packet already went through */
  72                 u8 recursion_counter:4;
  73
  74                 /* GRO is done by frag_list pointer chaining. */
  75                 u8      is_flist:1;
  76         );
  77
  78         /* used to support CHECKSUM_COMPLETE for tunneling protocols */
  79         __wsum  csum;
  80
  81         /* used in skb_gro_receive() slow path */
  82         struct sk_buff *last;
  83 };
  84
  85 #define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb)
  86
  87 #define GRO_RECURSION_LIMIT 15
  88 static inline int gro_recursion_inc_test(struct sk_buff *skb)
  89 {
  90         return ++NAPI_GRO_CB(skb)->recursion_counter == GRO_RECURSION_LIMIT;
  91 }
  92
  93 typedef struct sk_buff *(*gro_receive_t)(struct list_head *, struct sk_buff *);
  94 static inline struct sk_buff *call_gro_receive(gro_receive_t cb,
  95                                                struct list_head *head,
  96                                                struct sk_buff *skb)
  97 {
  98         if (unlikely(gro_recursion_inc_test(skb))) {
  99                 NAPI_GRO_CB(skb)->flush |= 1;
 100                 return NULL;
 101         }
 102
 103         return cb(head, skb);
 104 }
 105
 106 typedef struct sk_buff *(*gro_receive_sk_t)(struct sock *, struct list_head *,
 107                                             struct sk_buff *);
 108 static inline struct sk_buff *call_gro_receive_sk(gro_receive_sk_t cb,
 109                                                   struct sock *sk,
 110                                                   struct list_head *head,
 111                                                   struct sk_buff *skb)
 112 {
 113         if (unlikely(gro_recursion_inc_test(skb))) {
 114                 NAPI_GRO_CB(skb)->flush |= 1;
 115                 return NULL;
 116         }
 117
 118         return cb(sk, head, skb);
 119 }
 120
 121 static inline unsigned int skb_gro_offset(const struct sk_buff *skb)
 122 {
 123         return NAPI_GRO_CB(skb)->data_offset;
 124 }
 125
 126 static inline unsigned int skb_gro_len(const struct sk_buff *skb)
 127 {
 128         return skb->len - NAPI_GRO_CB(skb)->data_offset;
 129 }
 130
 131 static inline void skb_gro_pull(struct sk_buff *skb, unsigned int len)
 132 {
 133         NAPI_GRO_CB(skb)->data_offset += len;
 134 }
 135
 136 static inline void *skb_gro_header_fast(struct sk_buff *skb,
 137                                         unsigned int offset)
 138 {
 139         return NAPI_GRO_CB(skb)->frag0 + offset;
 140 }
 141
 142 static inline int skb_gro_header_hard(struct sk_buff *skb, unsigned int hlen)
 143 {
 144         return NAPI_GRO_CB(skb)->frag0_len < hlen;
 145 }
 146
 147 static inline void skb_gro_frag0_invalidate(struct sk_buff *skb)
 148 {
 149         NAPI_GRO_CB(skb)->frag0 = NULL;
 150         NAPI_GRO_CB(skb)->frag0_len = 0;
 151 }
 152
 153 static inline void *skb_gro_header_slow(struct sk_buff *skb, unsigned int hlen,
 154                                         unsigned int offset)
 155 {
 156         if (!pskb_may_pull(skb, hlen))
 157                 return NULL;
 158
 159         skb_gro_frag0_invalidate(skb);
 160         return skb->data + offset;
 161 }
 162
 163 static inline void *skb_gro_network_header(struct sk_buff *skb)
 164 {
 165         return (NAPI_GRO_CB(skb)->frag0 ?: skb->data) +
 166                skb_network_offset(skb);
 167 }
 168
 169 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
 170 {
 171         const struct iphdr *iph = skb_gro_network_header(skb);
 172
 173         return csum_tcpudp_nofold(iph->saddr, iph->daddr,
 174                                   skb_gro_len(skb), proto, 0);
 175 }
 176
 177 static inline void skb_gro_postpull_rcsum(struct sk_buff *skb,
 178                                         const void *start, unsigned int len)
 179 {
 180         if (NAPI_GRO_CB(skb)->csum_valid)
 181                 NAPI_GRO_CB(skb)->csum = wsum_negate(csum_partial(start, len,
 182                                                 wsum_negate(NAPI_GRO_CB(skb)->csum)));
 183 }
 184
 185 /* GRO checksum functions. These are logical equivalents of the normal
 186  * checksum functions (in skbuff.h) except that they operate on the GRO
 187  * offsets and fields in sk_buff.
 188  */
 189
 190 __sum16 __skb_gro_checksum_complete(struct sk_buff *skb);
 191
 192 static inline bool skb_at_gro_remcsum_start(struct sk_buff *skb)
 193 {
 194         return (NAPI_GRO_CB(skb)->gro_remcsum_start == skb_gro_offset(skb));
 195 }
 196
 197 static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb,
 198                                                       bool zero_okay,
 199                                                       __sum16 check)
 200 {
 201         return ((skb->ip_summed != CHECKSUM_PARTIAL ||
 202                 skb_checksum_start_offset(skb) <
 203                  skb_gro_offset(skb)) &&
 204                 !skb_at_gro_remcsum_start(skb) &&
 205                 NAPI_GRO_CB(skb)->csum_cnt == 0 &&
 206                 (!zero_okay || check));
 207 }
 208
 209 static inline __sum16 __skb_gro_checksum_validate_complete(struct sk_buff *skb,
 210                                                            __wsum psum)
 211 {
 212         if (NAPI_GRO_CB(skb)->csum_valid &&
 213             !csum_fold(csum_add(psum, NAPI_GRO_CB(skb)->csum)))
 214                 return 0;
 215
 216         NAPI_GRO_CB(skb)->csum = psum;
 217
 218         return __skb_gro_checksum_complete(skb);
 219 }
 220
 221 static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb)
 222 {
 223         if (NAPI_GRO_CB(skb)->csum_cnt > 0) {
 224                 /* Consume a checksum from CHECKSUM_UNNECESSARY */
 225                 NAPI_GRO_CB(skb)->csum_cnt--;
 226         } else {
 227                 /* Update skb for CHECKSUM_UNNECESSARY and csum_level when we
 228                  * verified a new top level checksum or an encapsulated one
 229                  * during GRO. This saves work if we fallback to normal path.
 230                  */
 231                 __skb_incr_checksum_unnecessary(skb);
 232         }
 233 }
 234
 235 #define __skb_gro_checksum_validate(skb, proto, zero_okay, check,       \
 236                                     compute_pseudo)                     \
 237 ({                                                                      \
 238         __sum16 __ret = 0;                                              \
 239         if (__skb_gro_checksum_validate_needed(skb, zero_okay, check))  \
 240                 __ret = __skb_gro_checksum_validate_complete(skb,       \
 241                                 compute_pseudo(skb, proto));            \
 242         if (!__ret)                                                     \
 243                 skb_gro_incr_csum_unnecessary(skb);                     \
 244         __ret;                                                          \
 245 })
 246
 247 #define skb_gro_checksum_validate(skb, proto, compute_pseudo)           \
 248         __skb_gro_checksum_validate(skb, proto, false, 0, compute_pseudo)
 249
 250 #define skb_gro_checksum_validate_zero_check(skb, proto, check,         \
 251                                              compute_pseudo)            \
 252         __skb_gro_checksum_validate(skb, proto, true, check, compute_pseudo)
 253
 254 #define skb_gro_checksum_simple_validate(skb)                           \
 255         __skb_gro_checksum_validate(skb, 0, false, 0, null_compute_pseudo)
 256
 257 static inline bool __skb_gro_checksum_convert_check(struct sk_buff *skb)
 258 {
 259         return (NAPI_GRO_CB(skb)->csum_cnt == 0 &&
 260                 !NAPI_GRO_CB(skb)->csum_valid);
 261 }
 262
 263 static inline void __skb_gro_checksum_convert(struct sk_buff *skb,
 264                                               __wsum pseudo)
 265 {
 266         NAPI_GRO_CB(skb)->csum = ~pseudo;
 267         NAPI_GRO_CB(skb)->csum_valid = 1;
 268 }
 269
 270 #define skb_gro_checksum_try_convert(skb, proto, compute_pseudo)        \
 271 do {                                                                    \
 272         if (__skb_gro_checksum_convert_check(skb))                      \
 273                 __skb_gro_checksum_convert(skb,                         \
 274                                            compute_pseudo(skb, proto)); \
 275 } while (0)
 276
 277 struct gro_remcsum {
 278         int offset;
 279         __wsum delta;
 280 };
 281
 282 static inline void skb_gro_remcsum_init(struct gro_remcsum *grc)
 283 {
 284         grc->offset = 0;
 285         grc->delta = 0;
 286 }
 287
 288 static inline void *skb_gro_remcsum_process(struct sk_buff *skb, void *ptr,
 289                                             unsigned int off, size_t hdrlen,
 290                                             int start, int offset,
 291                                             struct gro_remcsum *grc,
 292                                             bool nopartial)
 293 {
 294         __wsum delta;
 295         size_t plen = hdrlen + max_t(size_t, offset + sizeof(u16), start);
 296
 297         BUG_ON(!NAPI_GRO_CB(skb)->csum_valid);
 298
 299         if (!nopartial) {
 300                 NAPI_GRO_CB(skb)->gro_remcsum_start = off + hdrlen + start;
 301                 return ptr;
 302         }
 303
 304         ptr = skb_gro_header_fast(skb, off);
 305         if (skb_gro_header_hard(skb, off + plen)) {
 306                 ptr = skb_gro_header_slow(skb, off + plen, off);
 307                 if (!ptr)
 308                         return NULL;
 309         }
 310
 311         delta = remcsum_adjust(ptr + hdrlen, NAPI_GRO_CB(skb)->csum,
 312                                start, offset);
 313
 314         /* Adjust skb->csum since we changed the packet */
 315         NAPI_GRO_CB(skb)->csum = csum_add(NAPI_GRO_CB(skb)->csum, delta);
 316
 317         grc->offset = off + hdrlen + offset;
 318         grc->delta = delta;
 319
 320         return ptr;
 321 }
 322
 323 static inline void skb_gro_remcsum_cleanup(struct sk_buff *skb,
 324                                            struct gro_remcsum *grc)
 325 {
 326         void *ptr;
 327         size_t plen = grc->offset + sizeof(u16);
 328
 329         if (!grc->delta)
 330                 return;
 331
 332         ptr = skb_gro_header_fast(skb, grc->offset);
 333         if (skb_gro_header_hard(skb, grc->offset + sizeof(u16))) {
 334                 ptr = skb_gro_header_slow(skb, plen, grc->offset);
 335                 if (!ptr)
 336                         return;
 337         }
 338
 339         remcsum_unadjust((__sum16 *)ptr, grc->delta);
 340 }
 341
 342 #ifdef CONFIG_XFRM_OFFLOAD
 343 static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
 344 {
 345         if (PTR_ERR(pp) != -EINPROGRESS)
 346                 NAPI_GRO_CB(skb)->flush |= flush;
 347 }
 348 static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
 349                                                struct sk_buff *pp,
 350                                                int flush,
 351                                                struct gro_remcsum *grc)
 352 {
 353         if (PTR_ERR(pp) != -EINPROGRESS) {
 354                 NAPI_GRO_CB(skb)->flush |= flush;
 355                 skb_gro_remcsum_cleanup(skb, grc);
 356                 skb->remcsum_offload = 0;
 357         }
 358 }
 359 #else
 360 static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
 361 {
 362         NAPI_GRO_CB(skb)->flush |= flush;
 363 }
 364 static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
 365                                                struct sk_buff *pp,
 366                                                int flush,
 367                                                struct gro_remcsum *grc)
 368 {
 369         NAPI_GRO_CB(skb)->flush |= flush;
 370         skb_gro_remcsum_cleanup(skb, grc);
 371         skb->remcsum_offload = 0;
 372 }
 373 #endif
 374
 375 INDIRECT_CALLABLE_DECLARE(struct sk_buff *ipv6_gro_receive(struct list_head *,
 376                                                            struct sk_buff *));
 377 INDIRECT_CALLABLE_DECLARE(int ipv6_gro_complete(struct sk_buff *, int));
 378 INDIRECT_CALLABLE_DECLARE(struct sk_buff *inet_gro_receive(struct list_head *,
 379                                                            struct sk_buff *));
 380 INDIRECT_CALLABLE_DECLARE(int inet_gro_complete(struct sk_buff *, int));
 381
 382 INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
 383                                                            struct sk_buff *));
 384 INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));
 385
 386 INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp6_gro_receive(struct list_head *,
 387                                                            struct sk_buff *));
 388 INDIRECT_CALLABLE_DECLARE(int udp6_gro_complete(struct sk_buff *, int));
 389
 390 #define indirect_call_gro_receive_inet(cb, f2, f1, head, skb)   \
 391 ({                                                              \
 392         unlikely(gro_recursion_inc_test(skb)) ?                 \
 393                 NAPI_GRO_CB(skb)->flush |= 1, NULL :            \
 394                 INDIRECT_CALL_INET(cb, f2, f1, head, skb);      \
 395 })
 396
 397 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
 398                                 struct udphdr *uh, struct sock *sk);
 399 int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup);
 400
 401 static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
 402 {
 403         struct udphdr *uh;
 404         unsigned int hlen, off;
 405
 406         off  = skb_gro_offset(skb);
 407         hlen = off + sizeof(*uh);
 408         uh   = skb_gro_header_fast(skb, off);
 409         if (skb_gro_header_hard(skb, hlen))
 410                 uh = skb_gro_header_slow(skb, hlen, off);
 411
 412         return uh;
 413 }
 414
 415 static inline __wsum ip6_gro_compute_pseudo(struct sk_buff *skb, int proto)
 416 {
 417         const struct ipv6hdr *iph = skb_gro_network_header(skb);
 418
 419         return ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr,
 420                                             skb_gro_len(skb), proto, 0));
 421 }
 422
 423 int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb);
 424
 425 /* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
 426 static inline void gro_normal_list(struct napi_struct *napi)
 427 {
 428         if (!napi->rx_count)
 429                 return;
 430         netif_receive_skb_list_internal(&napi->rx_list);
 431         INIT_LIST_HEAD(&napi->rx_list);
 432         napi->rx_count = 0;
 433 }
 434
 435 /* Queue one GRO_NORMAL SKB up for list processing. If batch size exceeded,
 436  * pass the whole batch up to the stack.
 437  */
 438 static inline void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb, int segs)
 439 {
 440         list_add_tail(&skb->list, &napi->rx_list);
 441         napi->rx_count += segs;
 442         if (napi->rx_count >= gro_normal_batch)
 443                 gro_normal_list(napi);
 444 }
 445
 446
 447 #endif /* _NET_IPV6_GRO_H */