The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/sys/mbuf.h

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    1 /*-
    2  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 1982, 1986, 1988, 1993
    5  *      The Regents of the University of California.
    6  * All rights reserved.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  * 3. Neither the name of the University nor the names of its contributors
   17  *    may be used to endorse or promote products derived from this software
   18  *    without specific prior written permission.
   19  *
   20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   30  * SUCH DAMAGE.
   31  *
   32  *      @(#)mbuf.h      8.5 (Berkeley) 2/19/95
   33  * $FreeBSD: head/sys/sys/mbuf.h 346281 2019-04-16 16:49:34Z gallatin $
   34  */
   35 
   36 #ifndef _SYS_MBUF_H_
   37 #define _SYS_MBUF_H_
   38 
   39 /* XXX: These includes suck. Sorry! */
   40 #include <sys/queue.h>
   41 #ifdef _KERNEL
   42 #include <sys/systm.h>
   43 #include <vm/uma.h>
   44 #ifdef WITNESS
   45 #include <sys/lock.h>
   46 #endif
   47 #endif
   48 
   49 #ifdef _KERNEL
   50 #include <sys/sdt.h>
   51 
   52 #define MBUF_PROBE1(probe, arg0)                                        \
   53         SDT_PROBE1(sdt, , , probe, arg0)
   54 #define MBUF_PROBE2(probe, arg0, arg1)                                  \
   55         SDT_PROBE2(sdt, , , probe, arg0, arg1)
   56 #define MBUF_PROBE3(probe, arg0, arg1, arg2)                            \
   57         SDT_PROBE3(sdt, , , probe, arg0, arg1, arg2)
   58 #define MBUF_PROBE4(probe, arg0, arg1, arg2, arg3)                      \
   59         SDT_PROBE4(sdt, , , probe, arg0, arg1, arg2, arg3)
   60 #define MBUF_PROBE5(probe, arg0, arg1, arg2, arg3, arg4)                \
   61         SDT_PROBE5(sdt, , , probe, arg0, arg1, arg2, arg3, arg4)
   62 
   63 SDT_PROBE_DECLARE(sdt, , , m__init);
   64 SDT_PROBE_DECLARE(sdt, , , m__gethdr);
   65 SDT_PROBE_DECLARE(sdt, , , m__get);
   66 SDT_PROBE_DECLARE(sdt, , , m__getcl);
   67 SDT_PROBE_DECLARE(sdt, , , m__clget);
   68 SDT_PROBE_DECLARE(sdt, , , m__cljget);
   69 SDT_PROBE_DECLARE(sdt, , , m__cljset);
   70 SDT_PROBE_DECLARE(sdt, , , m__free);
   71 SDT_PROBE_DECLARE(sdt, , , m__freem);
   72 
   73 #endif /* _KERNEL */
   74 
   75 /*
   76  * Mbufs are of a single size, MSIZE (sys/param.h), which includes overhead.
   77  * An mbuf may add a single "mbuf cluster" of size MCLBYTES (also in
   78  * sys/param.h), which has no additional overhead and is used instead of the
   79  * internal data area; this is done when at least MINCLSIZE of data must be
   80  * stored.  Additionally, it is possible to allocate a separate buffer
   81  * externally and attach it to the mbuf in a way similar to that of mbuf
   82  * clusters.
   83  *
   84  * NB: These calculation do not take actual compiler-induced alignment and
   85  * padding inside the complete struct mbuf into account.  Appropriate
   86  * attention is required when changing members of struct mbuf.
   87  *
   88  * MLEN is data length in a normal mbuf.
   89  * MHLEN is data length in an mbuf with pktheader.
   90  * MINCLSIZE is a smallest amount of data that should be put into cluster.
   91  *
   92  * Compile-time assertions in uipc_mbuf.c test these values to ensure that
   93  * they are sensible.
   94  */
   95 struct mbuf;
   96 #define MHSIZE          offsetof(struct mbuf, m_dat)
   97 #define MPKTHSIZE       offsetof(struct mbuf, m_pktdat)
   98 #define MLEN            ((int)(MSIZE - MHSIZE))
   99 #define MHLEN           ((int)(MSIZE - MPKTHSIZE))
  100 #define MINCLSIZE       (MHLEN + 1)
  101 #define M_NODOM         255
  102 
  103 #ifdef _KERNEL
  104 /*-
  105  * Macro for type conversion: convert mbuf pointer to data pointer of correct
  106  * type:
  107  *
  108  * mtod(m, t)   -- Convert mbuf pointer to data pointer of correct type.
  109  * mtodo(m, o) -- Same as above but with offset 'o' into data.
  110  */
  111 #define mtod(m, t)      ((t)((m)->m_data))
  112 #define mtodo(m, o)     ((void *)(((m)->m_data) + (o)))
  113 
  114 /*
  115  * Argument structure passed to UMA routines during mbuf and packet
  116  * allocations.
  117  */
  118 struct mb_args {
  119         int     flags;  /* Flags for mbuf being allocated */
  120         short   type;   /* Type of mbuf being allocated */
  121 };
  122 #endif /* _KERNEL */
  123 
  124 /*
  125  * Packet tag structure (see below for details).
  126  */
  127 struct m_tag {
  128         SLIST_ENTRY(m_tag)      m_tag_link;     /* List of packet tags */
  129         u_int16_t               m_tag_id;       /* Tag ID */
  130         u_int16_t               m_tag_len;      /* Length of data */
  131         u_int32_t               m_tag_cookie;   /* ABI/Module ID */
  132         void                    (*m_tag_free)(struct m_tag *);
  133 };
  134 
  135 /*
  136  * Static network interface owned tag.
  137  * Allocated through ifp->if_snd_tag_alloc().
  138  */
  139 struct m_snd_tag {
  140         struct ifnet *ifp;              /* network interface tag belongs to */
  141 };
  142 
  143 /*
  144  * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
  145  * Size ILP32: 48
  146  *       LP64: 56
  147  * Compile-time assertions in uipc_mbuf.c test these values to ensure that
  148  * they are correct.
  149  */
  150 struct pkthdr {
  151         union {
  152                 struct m_snd_tag *snd_tag;      /* send tag, if any */
  153                 struct ifnet    *rcvif;         /* rcv interface */
  154         };
  155         SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
  156         int32_t          len;           /* total packet length */
  157 
  158         /* Layer crossing persistent information. */
  159         uint32_t         flowid;        /* packet's 4-tuple system */
  160         uint32_t         csum_flags;    /* checksum and offload features */
  161         uint16_t         fibnum;        /* this packet should use this fib */
  162         uint8_t          numa_domain;   /* NUMA domain of recvd pkt */
  163         uint8_t          rsstype;       /* hash type */
  164         union {
  165                 uint64_t        rcv_tstmp;      /* timestamp in ns */
  166                 struct {
  167                         uint8_t          l2hlen;        /* layer 2 hdr len */
  168                         uint8_t          l3hlen;        /* layer 3 hdr len */
  169                         uint8_t          l4hlen;        /* layer 4 hdr len */
  170                         uint8_t          l5hlen;        /* layer 5 hdr len */
  171                         uint32_t         spare;
  172                 };
  173         };
  174         union {
  175                 uint8_t  eight[8];
  176                 uint16_t sixteen[4];
  177                 uint32_t thirtytwo[2];
  178                 uint64_t sixtyfour[1];
  179                 uintptr_t unintptr[1];
  180                 void    *ptr;
  181         } PH_per;
  182 
  183         /* Layer specific non-persistent local storage for reassembly, etc. */
  184         union {
  185                 uint8_t  eight[8];
  186                 uint16_t sixteen[4];
  187                 uint32_t thirtytwo[2];
  188                 uint64_t sixtyfour[1];
  189                 uintptr_t unintptr[1];
  190                 void    *ptr;
  191         } PH_loc;
  192 };
  193 #define ether_vtag      PH_per.sixteen[0]
  194 #define PH_vt           PH_per
  195 #define vt_nrecs        sixteen[0]
  196 #define tso_segsz       PH_per.sixteen[1]
  197 #define lro_nsegs       tso_segsz
  198 #define csum_phsum      PH_per.sixteen[2]
  199 #define csum_data       PH_per.thirtytwo[1]
  200 #define pace_thoff      PH_loc.sixteen[0]
  201 #define pace_tlen       PH_loc.sixteen[1]
  202 #define pace_drphdrlen  PH_loc.sixteen[2]
  203 #define pace_tos        PH_loc.eight[6]
  204 #define pace_lock       PH_loc.eight[7]
  205 
  206 /*
  207  * Description of external storage mapped into mbuf; valid only if M_EXT is
  208  * set.
  209  * Size ILP32: 28
  210  *       LP64: 48
  211  * Compile-time assertions in uipc_mbuf.c test these values to ensure that
  212  * they are correct.
  213  */
  214 typedef void m_ext_free_t(struct mbuf *);
  215 struct m_ext {
  216         union {
  217                 /*
  218                  * If EXT_FLAG_EMBREF is set, then we use refcount in the
  219                  * mbuf, the 'ext_count' member.  Otherwise, we have a
  220                  * shadow copy and we use pointer 'ext_cnt'.  The original
  221                  * mbuf is responsible to carry the pointer to free routine
  222                  * and its arguments.  They aren't copied into shadows in
  223                  * mb_dupcl() to avoid dereferencing next cachelines.
  224                  */
  225                 volatile u_int   ext_count;
  226                 volatile u_int  *ext_cnt;
  227         };
  228         char            *ext_buf;       /* start of buffer */
  229         uint32_t         ext_size;      /* size of buffer, for ext_free */
  230         uint32_t         ext_type:8,    /* type of external storage */
  231                          ext_flags:24;  /* external storage mbuf flags */
  232         /*
  233          * Fields below store the free context for the external storage.
  234          * They are valid only in the refcount carrying mbuf, the one with
  235          * EXT_FLAG_EMBREF flag, with exclusion for EXT_EXTREF type, where
  236          * the free context is copied into all mbufs that use same external
  237          * storage.
  238          */
  239 #define m_ext_copylen   offsetof(struct m_ext, ext_free)
  240         m_ext_free_t    *ext_free;      /* free routine if not the usual */
  241         void            *ext_arg1;      /* optional argument pointer */
  242         void            *ext_arg2;      /* optional argument pointer */
  243 };
  244 
  245 /*
  246  * The core of the mbuf object along with some shortcut defines for practical
  247  * purposes.
  248  */
  249 struct mbuf {
  250         /*
  251          * Header present at the beginning of every mbuf.
  252          * Size ILP32: 24
  253          *      LP64: 32
  254          * Compile-time assertions in uipc_mbuf.c test these values to ensure
  255          * that they are correct.
  256          */
  257         union { /* next buffer in chain */
  258                 struct mbuf             *m_next;
  259                 SLIST_ENTRY(mbuf)       m_slist;
  260                 STAILQ_ENTRY(mbuf)      m_stailq;
  261         };
  262         union { /* next chain in queue/record */
  263                 struct mbuf             *m_nextpkt;
  264                 SLIST_ENTRY(mbuf)       m_slistpkt;
  265                 STAILQ_ENTRY(mbuf)      m_stailqpkt;
  266         };
  267         caddr_t          m_data;        /* location of data */
  268         int32_t          m_len;         /* amount of data in this mbuf */
  269         uint32_t         m_type:8,      /* type of data in this mbuf */
  270                          m_flags:24;    /* flags; see below */
  271 #if !defined(__LP64__)
  272         uint32_t         m_pad;         /* pad for 64bit alignment */
  273 #endif
  274 
  275         /*
  276          * A set of optional headers (packet header, external storage header)
  277          * and internal data storage.  Historically, these arrays were sized
  278          * to MHLEN (space left after a packet header) and MLEN (space left
  279          * after only a regular mbuf header); they are now variable size in
  280          * order to support future work on variable-size mbufs.
  281          */
  282         union {
  283                 struct {
  284                         struct pkthdr   m_pkthdr;       /* M_PKTHDR set */
  285                         union {
  286                                 struct m_ext    m_ext;  /* M_EXT set */
  287                                 char            m_pktdat[0];
  288                         };
  289                 };
  290                 char    m_dat[0];                       /* !M_PKTHDR, !M_EXT */
  291         };
  292 };
  293 
  294 /*
  295  * mbuf flags of global significance and layer crossing.
  296  * Those of only protocol/layer specific significance are to be mapped
  297  * to M_PROTO[1-12] and cleared at layer handoff boundaries.
  298  * NB: Limited to the lower 24 bits.
  299  */
  300 #define M_EXT           0x00000001 /* has associated external storage */
  301 #define M_PKTHDR        0x00000002 /* start of record */
  302 #define M_EOR           0x00000004 /* end of record */
  303 #define M_RDONLY        0x00000008 /* associated data is marked read-only */
  304 #define M_BCAST         0x00000010 /* send/received as link-level broadcast */
  305 #define M_MCAST         0x00000020 /* send/received as link-level multicast */
  306 #define M_PROMISC       0x00000040 /* packet was not for us */
  307 #define M_VLANTAG       0x00000080 /* ether_vtag is valid */
  308 #define M_NOMAP         0x00000100 /* mbuf data is unmapped (soon from Drew) */
  309 #define M_NOFREE        0x00000200 /* do not free mbuf, embedded in cluster */
  310 #define M_TSTMP         0x00000400 /* rcv_tstmp field is valid */
  311 #define M_TSTMP_HPREC   0x00000800 /* rcv_tstmp is high-prec, typically
  312                                       hw-stamped on port (useful for IEEE 1588
  313                                       and 802.1AS) */
  314 
  315 #define M_PROTO1        0x00001000 /* protocol-specific */
  316 #define M_PROTO2        0x00002000 /* protocol-specific */
  317 #define M_PROTO3        0x00004000 /* protocol-specific */
  318 #define M_PROTO4        0x00008000 /* protocol-specific */
  319 #define M_PROTO5        0x00010000 /* protocol-specific */
  320 #define M_PROTO6        0x00020000 /* protocol-specific */
  321 #define M_PROTO7        0x00040000 /* protocol-specific */
  322 #define M_PROTO8        0x00080000 /* protocol-specific */
  323 #define M_PROTO9        0x00100000 /* protocol-specific */
  324 #define M_PROTO10       0x00200000 /* protocol-specific */
  325 #define M_PROTO11       0x00400000 /* protocol-specific */
  326 #define M_PROTO12       0x00800000 /* protocol-specific */
  327 
  328 #define MB_DTOR_SKIP    0x1     /* don't pollute the cache by touching a freed mbuf */
  329 
  330 /*
  331  * Flags to purge when crossing layers.
  332  */
  333 #define M_PROTOFLAGS \
  334     (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8|\
  335      M_PROTO9|M_PROTO10|M_PROTO11|M_PROTO12)
  336 
  337 /*
  338  * Flags preserved when copying m_pkthdr.
  339  */
  340 #define M_COPYFLAGS \
  341     (M_PKTHDR|M_EOR|M_RDONLY|M_BCAST|M_MCAST|M_PROMISC|M_VLANTAG|M_TSTMP| \
  342      M_TSTMP_HPREC|M_PROTOFLAGS)
  343 
  344 /*
  345  * Mbuf flag description for use with printf(9) %b identifier.
  346  */
  347 #define M_FLAG_BITS \
  348     "\2\1M_EXT\2M_PKTHDR\3M_EOR\4M_RDONLY\5M_BCAST\6M_MCAST" \
  349     "\7M_PROMISC\10M_VLANTAG\13M_TSTMP\14M_TSTMP_HPREC"
  350 #define M_FLAG_PROTOBITS \
  351     "\15M_PROTO1\16M_PROTO2\17M_PROTO3\20M_PROTO4\21M_PROTO5" \
  352     "\22M_PROTO6\23M_PROTO7\24M_PROTO8\25M_PROTO9\26M_PROTO10" \
  353     "\27M_PROTO11\30M_PROTO12"
  354 #define M_FLAG_PRINTF (M_FLAG_BITS M_FLAG_PROTOBITS)
  355 
  356 /*
  357  * Network interface cards are able to hash protocol fields (such as IPv4
  358  * addresses and TCP port numbers) classify packets into flows.  These flows
  359  * can then be used to maintain ordering while delivering packets to the OS
  360  * via parallel input queues, as well as to provide a stateless affinity
  361  * model.  NIC drivers can pass up the hash via m->m_pkthdr.flowid, and set
  362  * m_flag fields to indicate how the hash should be interpreted by the
  363  * network stack.
  364  *
  365  * Most NICs support RSS, which provides ordering and explicit affinity, and
  366  * use the hash m_flag bits to indicate what header fields were covered by
  367  * the hash.  M_HASHTYPE_OPAQUE and M_HASHTYPE_OPAQUE_HASH can be set by non-
  368  * RSS cards or configurations that provide an opaque flow identifier, allowing
  369  * for ordering and distribution without explicit affinity.  Additionally,
  370  * M_HASHTYPE_OPAQUE_HASH indicates that the flow identifier has hash
  371  * properties.
  372  *
  373  * The meaning of the IPV6_EX suffix:
  374  * "o  Home address from the home address option in the IPv6 destination
  375  *     options header.  If the extension header is not present, use the Source
  376  *     IPv6 Address.
  377  *  o  IPv6 address that is contained in the Routing-Header-Type-2 from the
  378  *     associated extension header.  If the extension header is not present,
  379  *     use the Destination IPv6 Address."
  380  * Quoted from:
  381  * https://docs.microsoft.com/en-us/windows-hardware/drivers/network/rss-hashing-types#ndishashipv6ex
  382  */
  383 #define M_HASHTYPE_HASHPROP             0x80    /* has hash properties */
  384 #define M_HASHTYPE_HASH(t)              (M_HASHTYPE_HASHPROP | (t))
  385 /* Microsoft RSS standard hash types */
  386 #define M_HASHTYPE_NONE                 0
  387 #define M_HASHTYPE_RSS_IPV4             M_HASHTYPE_HASH(1) /* IPv4 2-tuple */
  388 #define M_HASHTYPE_RSS_TCP_IPV4         M_HASHTYPE_HASH(2) /* TCPv4 4-tuple */
  389 #define M_HASHTYPE_RSS_IPV6             M_HASHTYPE_HASH(3) /* IPv6 2-tuple */
  390 #define M_HASHTYPE_RSS_TCP_IPV6         M_HASHTYPE_HASH(4) /* TCPv6 4-tuple */
  391 #define M_HASHTYPE_RSS_IPV6_EX          M_HASHTYPE_HASH(5) /* IPv6 2-tuple +
  392                                                             * ext hdrs */
  393 #define M_HASHTYPE_RSS_TCP_IPV6_EX      M_HASHTYPE_HASH(6) /* TCPv6 4-tuple +
  394                                                             * ext hdrs */
  395 #define M_HASHTYPE_RSS_UDP_IPV4         M_HASHTYPE_HASH(7) /* IPv4 UDP 4-tuple*/
  396 #define M_HASHTYPE_RSS_UDP_IPV6         M_HASHTYPE_HASH(9) /* IPv6 UDP 4-tuple*/
  397 #define M_HASHTYPE_RSS_UDP_IPV6_EX      M_HASHTYPE_HASH(10)/* IPv6 UDP 4-tuple +
  398                                                             * ext hdrs */
  399 
  400 #define M_HASHTYPE_OPAQUE               63      /* ordering, not affinity */
  401 #define M_HASHTYPE_OPAQUE_HASH          M_HASHTYPE_HASH(M_HASHTYPE_OPAQUE)
  402                                                 /* ordering+hash, not affinity*/
  403 
  404 #define M_HASHTYPE_CLEAR(m)     ((m)->m_pkthdr.rsstype = 0)
  405 #define M_HASHTYPE_GET(m)       ((m)->m_pkthdr.rsstype)
  406 #define M_HASHTYPE_SET(m, v)    ((m)->m_pkthdr.rsstype = (v))
  407 #define M_HASHTYPE_TEST(m, v)   (M_HASHTYPE_GET(m) == (v))
  408 #define M_HASHTYPE_ISHASH(m)    (M_HASHTYPE_GET(m) & M_HASHTYPE_HASHPROP)
  409 
  410 /*
  411  * External mbuf storage buffer types.
  412  */
  413 #define EXT_CLUSTER     1       /* mbuf cluster */
  414 #define EXT_SFBUF       2       /* sendfile(2)'s sf_buf */
  415 #define EXT_JUMBOP      3       /* jumbo cluster page sized */
  416 #define EXT_JUMBO9      4       /* jumbo cluster 9216 bytes */
  417 #define EXT_JUMBO16     5       /* jumbo cluster 16184 bytes */
  418 #define EXT_PACKET      6       /* mbuf+cluster from packet zone */
  419 #define EXT_MBUF        7       /* external mbuf reference */
  420 #define EXT_RXRING      8       /* data in NIC receive ring */
  421 
  422 #define EXT_VENDOR1     224     /* for vendor-internal use */
  423 #define EXT_VENDOR2     225     /* for vendor-internal use */
  424 #define EXT_VENDOR3     226     /* for vendor-internal use */
  425 #define EXT_VENDOR4     227     /* for vendor-internal use */
  426 
  427 #define EXT_EXP1        244     /* for experimental use */
  428 #define EXT_EXP2        245     /* for experimental use */
  429 #define EXT_EXP3        246     /* for experimental use */
  430 #define EXT_EXP4        247     /* for experimental use */
  431 
  432 #define EXT_NET_DRV     252     /* custom ext_buf provided by net driver(s) */
  433 #define EXT_MOD_TYPE    253     /* custom module's ext_buf type */
  434 #define EXT_DISPOSABLE  254     /* can throw this buffer away w/page flipping */
  435 #define EXT_EXTREF      255     /* has externally maintained ext_cnt ptr */
  436 
  437 /*
  438  * Flags for external mbuf buffer types.
  439  * NB: limited to the lower 24 bits.
  440  */
  441 #define EXT_FLAG_EMBREF         0x000001        /* embedded ext_count */
  442 #define EXT_FLAG_EXTREF         0x000002        /* external ext_cnt, notyet */
  443 
  444 #define EXT_FLAG_NOFREE         0x000010        /* don't free mbuf to pool, notyet */
  445 
  446 #define EXT_FLAG_VENDOR1        0x010000        /* These flags are vendor */
  447 #define EXT_FLAG_VENDOR2        0x020000        /* or submodule specific, */
  448 #define EXT_FLAG_VENDOR3        0x040000        /* not used by mbuf code. */
  449 #define EXT_FLAG_VENDOR4        0x080000        /* Set/read by submodule. */
  450 
  451 #define EXT_FLAG_EXP1           0x100000        /* for experimental use */
  452 #define EXT_FLAG_EXP2           0x200000        /* for experimental use */
  453 #define EXT_FLAG_EXP3           0x400000        /* for experimental use */
  454 #define EXT_FLAG_EXP4           0x800000        /* for experimental use */
  455 
  456 /*
  457  * EXT flag description for use with printf(9) %b identifier.
  458  */
  459 #define EXT_FLAG_BITS \
  460     "\2\1EXT_FLAG_EMBREF\2EXT_FLAG_EXTREF\5EXT_FLAG_NOFREE" \
  461     "\21EXT_FLAG_VENDOR1\22EXT_FLAG_VENDOR2\23EXT_FLAG_VENDOR3" \
  462     "\24EXT_FLAG_VENDOR4\25EXT_FLAG_EXP1\26EXT_FLAG_EXP2\27EXT_FLAG_EXP3" \
  463     "\30EXT_FLAG_EXP4"
  464 
  465 /*
  466  * Flags indicating checksum, segmentation and other offload work to be
  467  * done, or already done, by hardware or lower layers.  It is split into
  468  * separate inbound and outbound flags.
  469  *
  470  * Outbound flags that are set by upper protocol layers requesting lower
  471  * layers, or ideally the hardware, to perform these offloading tasks.
  472  * For outbound packets this field and its flags can be directly tested
  473  * against ifnet if_hwassist.
  474  */
  475 #define CSUM_IP                 0x00000001      /* IP header checksum offload */
  476 #define CSUM_IP_UDP             0x00000002      /* UDP checksum offload */
  477 #define CSUM_IP_TCP             0x00000004      /* TCP checksum offload */
  478 #define CSUM_IP_SCTP            0x00000008      /* SCTP checksum offload */
  479 #define CSUM_IP_TSO             0x00000010      /* TCP segmentation offload */
  480 #define CSUM_IP_ISCSI           0x00000020      /* iSCSI checksum offload */
  481 
  482 #define CSUM_IP6_UDP            0x00000200      /* UDP checksum offload */
  483 #define CSUM_IP6_TCP            0x00000400      /* TCP checksum offload */
  484 #define CSUM_IP6_SCTP           0x00000800      /* SCTP checksum offload */
  485 #define CSUM_IP6_TSO            0x00001000      /* TCP segmentation offload */
  486 #define CSUM_IP6_ISCSI          0x00002000      /* iSCSI checksum offload */
  487 
  488 /* Inbound checksum support where the checksum was verified by hardware. */
  489 #define CSUM_L3_CALC            0x01000000      /* calculated layer 3 csum */
  490 #define CSUM_L3_VALID           0x02000000      /* checksum is correct */
  491 #define CSUM_L4_CALC            0x04000000      /* calculated layer 4 csum */
  492 #define CSUM_L4_VALID           0x08000000      /* checksum is correct */
  493 #define CSUM_L5_CALC            0x10000000      /* calculated layer 5 csum */
  494 #define CSUM_L5_VALID           0x20000000      /* checksum is correct */
  495 #define CSUM_COALESCED          0x40000000      /* contains merged segments */
  496 
  497 /*
  498  * CSUM flag description for use with printf(9) %b identifier.
  499  */
  500 #define CSUM_BITS \
  501     "\2\1CSUM_IP\2CSUM_IP_UDP\3CSUM_IP_TCP\4CSUM_IP_SCTP\5CSUM_IP_TSO" \
  502     "\6CSUM_IP_ISCSI" \
  503     "\12CSUM_IP6_UDP\13CSUM_IP6_TCP\14CSUM_IP6_SCTP\15CSUM_IP6_TSO" \
  504     "\16CSUM_IP6_ISCSI" \
  505     "\31CSUM_L3_CALC\32CSUM_L3_VALID\33CSUM_L4_CALC\34CSUM_L4_VALID" \
  506     "\35CSUM_L5_CALC\36CSUM_L5_VALID\37CSUM_COALESCED"
  507 
  508 /* CSUM flags compatibility mappings. */
  509 #define CSUM_IP_CHECKED         CSUM_L3_CALC
  510 #define CSUM_IP_VALID           CSUM_L3_VALID
  511 #define CSUM_DATA_VALID         CSUM_L4_VALID
  512 #define CSUM_PSEUDO_HDR         CSUM_L4_CALC
  513 #define CSUM_SCTP_VALID         CSUM_L4_VALID
  514 #define CSUM_DELAY_DATA         (CSUM_TCP|CSUM_UDP)
  515 #define CSUM_DELAY_IP           CSUM_IP         /* Only v4, no v6 IP hdr csum */
  516 #define CSUM_DELAY_DATA_IPV6    (CSUM_TCP_IPV6|CSUM_UDP_IPV6)
  517 #define CSUM_DATA_VALID_IPV6    CSUM_DATA_VALID
  518 #define CSUM_TCP                CSUM_IP_TCP
  519 #define CSUM_UDP                CSUM_IP_UDP
  520 #define CSUM_SCTP               CSUM_IP_SCTP
  521 #define CSUM_TSO                (CSUM_IP_TSO|CSUM_IP6_TSO)
  522 #define CSUM_UDP_IPV6           CSUM_IP6_UDP
  523 #define CSUM_TCP_IPV6           CSUM_IP6_TCP
  524 #define CSUM_SCTP_IPV6          CSUM_IP6_SCTP
  525 
  526 /*
  527  * mbuf types describing the content of the mbuf (including external storage).
  528  */
  529 #define MT_NOTMBUF      0       /* USED INTERNALLY ONLY! Object is not mbuf */
  530 #define MT_DATA         1       /* dynamic (data) allocation */
  531 #define MT_HEADER       MT_DATA /* packet header, use M_PKTHDR instead */
  532 
  533 #define MT_VENDOR1      4       /* for vendor-internal use */
  534 #define MT_VENDOR2      5       /* for vendor-internal use */
  535 #define MT_VENDOR3      6       /* for vendor-internal use */
  536 #define MT_VENDOR4      7       /* for vendor-internal use */
  537 
  538 #define MT_SONAME       8       /* socket name */
  539 
  540 #define MT_EXP1         9       /* for experimental use */
  541 #define MT_EXP2         10      /* for experimental use */
  542 #define MT_EXP3         11      /* for experimental use */
  543 #define MT_EXP4         12      /* for experimental use */
  544 
  545 #define MT_CONTROL      14      /* extra-data protocol message */
  546 #define MT_EXTCONTROL   15      /* control message with externalized contents */
  547 #define MT_OOBDATA      16      /* expedited data  */
  548 
  549 #define MT_NOINIT       255     /* Not a type but a flag to allocate
  550                                    a non-initialized mbuf */
  551 
  552 /*
  553  * String names of mbuf-related UMA(9) and malloc(9) types.  Exposed to
  554  * !_KERNEL so that monitoring tools can look up the zones with
  555  * libmemstat(3).
  556  */
  557 #define MBUF_MEM_NAME           "mbuf"
  558 #define MBUF_CLUSTER_MEM_NAME   "mbuf_cluster"
  559 #define MBUF_PACKET_MEM_NAME    "mbuf_packet"
  560 #define MBUF_JUMBOP_MEM_NAME    "mbuf_jumbo_page"
  561 #define MBUF_JUMBO9_MEM_NAME    "mbuf_jumbo_9k"
  562 #define MBUF_JUMBO16_MEM_NAME   "mbuf_jumbo_16k"
  563 #define MBUF_TAG_MEM_NAME       "mbuf_tag"
  564 #define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt"
  565 
  566 #ifdef _KERNEL
  567 
  568 #ifdef WITNESS
  569 #define MBUF_CHECKSLEEP(how) do {                                       \
  570         if (how == M_WAITOK)                                            \
  571                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,         \
  572                     "Sleeping in \"%s\"", __func__);                    \
  573 } while (0)
  574 #else
  575 #define MBUF_CHECKSLEEP(how)
  576 #endif
  577 
  578 /*
  579  * Network buffer allocation API
  580  *
  581  * The rest of it is defined in kern/kern_mbuf.c
  582  */
  583 extern uma_zone_t       zone_mbuf;
  584 extern uma_zone_t       zone_clust;
  585 extern uma_zone_t       zone_pack;
  586 extern uma_zone_t       zone_jumbop;
  587 extern uma_zone_t       zone_jumbo9;
  588 extern uma_zone_t       zone_jumbo16;
  589 
  590 void             mb_dupcl(struct mbuf *, struct mbuf *);
  591 void             mb_free_ext(struct mbuf *);
  592 void             m_adj(struct mbuf *, int);
  593 int              m_apply(struct mbuf *, int, int,
  594                     int (*)(void *, void *, u_int), void *);
  595 int              m_append(struct mbuf *, int, c_caddr_t);
  596 void             m_cat(struct mbuf *, struct mbuf *);
  597 void             m_catpkt(struct mbuf *, struct mbuf *);
  598 int              m_clget(struct mbuf *m, int how);
  599 void            *m_cljget(struct mbuf *m, int how, int size);
  600 struct mbuf     *m_collapse(struct mbuf *, int, int);
  601 void             m_copyback(struct mbuf *, int, int, c_caddr_t);
  602 void             m_copydata(const struct mbuf *, int, int, caddr_t);
  603 struct mbuf     *m_copym(struct mbuf *, int, int, int);
  604 struct mbuf     *m_copypacket(struct mbuf *, int);
  605 void             m_copy_pkthdr(struct mbuf *, struct mbuf *);
  606 struct mbuf     *m_copyup(struct mbuf *, int, int);
  607 struct mbuf     *m_defrag(struct mbuf *, int);
  608 void             m_demote_pkthdr(struct mbuf *);
  609 void             m_demote(struct mbuf *, int, int);
  610 struct mbuf     *m_devget(char *, int, int, struct ifnet *,
  611                     void (*)(char *, caddr_t, u_int));
  612 void             m_dispose_extcontrolm(struct mbuf *m);
  613 struct mbuf     *m_dup(const struct mbuf *, int);
  614 int              m_dup_pkthdr(struct mbuf *, const struct mbuf *, int);
  615 void             m_extadd(struct mbuf *, char *, u_int, m_ext_free_t,
  616                     void *, void *, int, int);
  617 u_int            m_fixhdr(struct mbuf *);
  618 struct mbuf     *m_fragment(struct mbuf *, int, int);
  619 void             m_freem(struct mbuf *);
  620 struct mbuf     *m_get2(int, int, short, int);
  621 struct mbuf     *m_getjcl(int, short, int, int);
  622 struct mbuf     *m_getm2(struct mbuf *, int, int, short, int);
  623 struct mbuf     *m_getptr(struct mbuf *, int, int *);
  624 u_int            m_length(struct mbuf *, struct mbuf **);
  625 int              m_mbuftouio(struct uio *, const struct mbuf *, int);
  626 void             m_move_pkthdr(struct mbuf *, struct mbuf *);
  627 int              m_pkthdr_init(struct mbuf *, int);
  628 struct mbuf     *m_prepend(struct mbuf *, int, int);
  629 void             m_print(const struct mbuf *, int);
  630 struct mbuf     *m_pulldown(struct mbuf *, int, int, int *);
  631 struct mbuf     *m_pullup(struct mbuf *, int);
  632 int              m_sanity(struct mbuf *, int);
  633 struct mbuf     *m_split(struct mbuf *, int, int);
  634 struct mbuf     *m_uiotombuf(struct uio *, int, int, int, int);
  635 struct mbuf     *m_unshare(struct mbuf *, int);
  636 
  637 static __inline int
  638 m_gettype(int size)
  639 {
  640         int type;
  641 
  642         switch (size) {
  643         case MSIZE:
  644                 type = EXT_MBUF;
  645                 break;
  646         case MCLBYTES:
  647                 type = EXT_CLUSTER;
  648                 break;
  649 #if MJUMPAGESIZE != MCLBYTES
  650         case MJUMPAGESIZE:
  651                 type = EXT_JUMBOP;
  652                 break;
  653 #endif
  654         case MJUM9BYTES:
  655                 type = EXT_JUMBO9;
  656                 break;
  657         case MJUM16BYTES:
  658                 type = EXT_JUMBO16;
  659                 break;
  660         default:
  661                 panic("%s: invalid cluster size %d", __func__, size);
  662         }
  663 
  664         return (type);
  665 }
  666 
  667 /*
  668  * Associated an external reference counted buffer with an mbuf.
  669  */
  670 static __inline void
  671 m_extaddref(struct mbuf *m, char *buf, u_int size, u_int *ref_cnt,
  672     m_ext_free_t freef, void *arg1, void *arg2)
  673 {
  674 
  675         KASSERT(ref_cnt != NULL, ("%s: ref_cnt not provided", __func__));
  676 
  677         atomic_add_int(ref_cnt, 1);
  678         m->m_flags |= M_EXT;
  679         m->m_ext.ext_buf = buf;
  680         m->m_ext.ext_cnt = ref_cnt;
  681         m->m_data = m->m_ext.ext_buf;
  682         m->m_ext.ext_size = size;
  683         m->m_ext.ext_free = freef;
  684         m->m_ext.ext_arg1 = arg1;
  685         m->m_ext.ext_arg2 = arg2;
  686         m->m_ext.ext_type = EXT_EXTREF;
  687         m->m_ext.ext_flags = 0;
  688 }
  689 
  690 static __inline uma_zone_t
  691 m_getzone(int size)
  692 {
  693         uma_zone_t zone;
  694 
  695         switch (size) {
  696         case MCLBYTES:
  697                 zone = zone_clust;
  698                 break;
  699 #if MJUMPAGESIZE != MCLBYTES
  700         case MJUMPAGESIZE:
  701                 zone = zone_jumbop;
  702                 break;
  703 #endif
  704         case MJUM9BYTES:
  705                 zone = zone_jumbo9;
  706                 break;
  707         case MJUM16BYTES:
  708                 zone = zone_jumbo16;
  709                 break;
  710         default:
  711                 panic("%s: invalid cluster size %d", __func__, size);
  712         }
  713 
  714         return (zone);
  715 }
  716 
  717 /*
  718  * Initialize an mbuf with linear storage.
  719  *
  720  * Inline because the consumer text overhead will be roughly the same to
  721  * initialize or call a function with this many parameters and M_PKTHDR
  722  * should go away with constant propagation for !MGETHDR.
  723  */
  724 static __inline int
  725 m_init(struct mbuf *m, int how, short type, int flags)
  726 {
  727         int error;
  728 
  729         m->m_next = NULL;
  730         m->m_nextpkt = NULL;
  731         m->m_data = m->m_dat;
  732         m->m_len = 0;
  733         m->m_flags = flags;
  734         m->m_type = type;
  735         if (flags & M_PKTHDR)
  736                 error = m_pkthdr_init(m, how);
  737         else
  738                 error = 0;
  739 
  740         MBUF_PROBE5(m__init, m, how, type, flags, error);
  741         return (error);
  742 }
  743 
  744 static __inline struct mbuf *
  745 m_get(int how, short type)
  746 {
  747         struct mbuf *m;
  748         struct mb_args args;
  749 
  750         args.flags = 0;
  751         args.type = type;
  752         m = uma_zalloc_arg(zone_mbuf, &args, how);
  753         MBUF_PROBE3(m__get, how, type, m);
  754         return (m);
  755 }
  756 
  757 static __inline struct mbuf *
  758 m_gethdr(int how, short type)
  759 {
  760         struct mbuf *m;
  761         struct mb_args args;
  762 
  763         args.flags = M_PKTHDR;
  764         args.type = type;
  765         m = uma_zalloc_arg(zone_mbuf, &args, how);
  766         MBUF_PROBE3(m__gethdr, how, type, m);
  767         return (m);
  768 }
  769 
  770 static __inline struct mbuf *
  771 m_getcl(int how, short type, int flags)
  772 {
  773         struct mbuf *m;
  774         struct mb_args args;
  775 
  776         args.flags = flags;
  777         args.type = type;
  778         m = uma_zalloc_arg(zone_pack, &args, how);
  779         MBUF_PROBE4(m__getcl, how, type, flags, m);
  780         return (m);
  781 }
  782 
  783 /*
  784  * XXX: m_cljset() is a dangerous API.  One must attach only a new,
  785  * unreferenced cluster to an mbuf(9).  It is not possible to assert
  786  * that, so care can be taken only by users of the API.
  787  */
  788 static __inline void
  789 m_cljset(struct mbuf *m, void *cl, int type)
  790 {
  791         int size;
  792 
  793         switch (type) {
  794         case EXT_CLUSTER:
  795                 size = MCLBYTES;
  796                 break;
  797 #if MJUMPAGESIZE != MCLBYTES
  798         case EXT_JUMBOP:
  799                 size = MJUMPAGESIZE;
  800                 break;
  801 #endif
  802         case EXT_JUMBO9:
  803                 size = MJUM9BYTES;
  804                 break;
  805         case EXT_JUMBO16:
  806                 size = MJUM16BYTES;
  807                 break;
  808         default:
  809                 panic("%s: unknown cluster type %d", __func__, type);
  810                 break;
  811         }
  812 
  813         m->m_data = m->m_ext.ext_buf = cl;
  814         m->m_ext.ext_free = m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
  815         m->m_ext.ext_size = size;
  816         m->m_ext.ext_type = type;
  817         m->m_ext.ext_flags = EXT_FLAG_EMBREF;
  818         m->m_ext.ext_count = 1;
  819         m->m_flags |= M_EXT;
  820         MBUF_PROBE3(m__cljset, m, cl, type);
  821 }
  822 
  823 static __inline void
  824 m_chtype(struct mbuf *m, short new_type)
  825 {
  826 
  827         m->m_type = new_type;
  828 }
  829 
  830 static __inline void
  831 m_clrprotoflags(struct mbuf *m)
  832 {
  833 
  834         while (m) {
  835                 m->m_flags &= ~M_PROTOFLAGS;
  836                 m = m->m_next;
  837         }
  838 }
  839 
  840 static __inline struct mbuf *
  841 m_last(struct mbuf *m)
  842 {
  843 
  844         while (m->m_next)
  845                 m = m->m_next;
  846         return (m);
  847 }
  848 
  849 static inline u_int
  850 m_extrefcnt(struct mbuf *m)
  851 {
  852 
  853         KASSERT(m->m_flags & M_EXT, ("%s: M_EXT missing", __func__));
  854 
  855         return ((m->m_ext.ext_flags & EXT_FLAG_EMBREF) ? m->m_ext.ext_count :
  856             *m->m_ext.ext_cnt);
  857 }
  858 
  859 /*
  860  * mbuf, cluster, and external object allocation macros (for compatibility
  861  * purposes).
  862  */
  863 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from))
  864 #define MGET(m, how, type)      ((m) = m_get((how), (type)))
  865 #define MGETHDR(m, how, type)   ((m) = m_gethdr((how), (type)))
  866 #define MCLGET(m, how)          m_clget((m), (how))
  867 #define MEXTADD(m, buf, size, free, arg1, arg2, flags, type)            \
  868     m_extadd((m), (char *)(buf), (size), (free), (arg1), (arg2),        \
  869     (flags), (type))
  870 #define m_getm(m, len, how, type)                                       \
  871     m_getm2((m), (len), (how), (type), M_PKTHDR)
  872 
  873 /*
  874  * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can
  875  * be both the local data payload, or an external buffer area, depending on
  876  * whether M_EXT is set).
  877  */
  878 #define M_WRITABLE(m)   (!((m)->m_flags & M_RDONLY) &&                  \
  879                          (!(((m)->m_flags & M_EXT)) ||                  \
  880                          (m_extrefcnt(m) == 1)))
  881 
  882 /* Check if the supplied mbuf has a packet header, or else panic. */
  883 #define M_ASSERTPKTHDR(m)                                               \
  884         KASSERT((m) != NULL && (m)->m_flags & M_PKTHDR,                 \
  885             ("%s: no mbuf packet header!", __func__))
  886 
  887 /*
  888  * Ensure that the supplied mbuf is a valid, non-free mbuf.
  889  *
  890  * XXX: Broken at the moment.  Need some UMA magic to make it work again.
  891  */
  892 #define M_ASSERTVALID(m)                                                \
  893         KASSERT((((struct mbuf *)m)->m_flags & 0) == 0,                 \
  894             ("%s: attempted use of a free mbuf!", __func__))
  895 
  896 /*
  897  * Return the address of the start of the buffer associated with an mbuf,
  898  * handling external storage, packet-header mbufs, and regular data mbufs.
  899  */
  900 #define M_START(m)                                                      \
  901         (((m)->m_flags & M_EXT) ? (m)->m_ext.ext_buf :                  \
  902          ((m)->m_flags & M_PKTHDR) ? &(m)->m_pktdat[0] :                \
  903          &(m)->m_dat[0])
  904 
  905 /*
  906  * Return the size of the buffer associated with an mbuf, handling external
  907  * storage, packet-header mbufs, and regular data mbufs.
  908  */
  909 #define M_SIZE(m)                                                       \
  910         (((m)->m_flags & M_EXT) ? (m)->m_ext.ext_size :                 \
  911          ((m)->m_flags & M_PKTHDR) ? MHLEN :                            \
  912          MLEN)
  913 
  914 /*
  915  * Set the m_data pointer of a newly allocated mbuf to place an object of the
  916  * specified size at the end of the mbuf, longword aligned.
  917  *
  918  * NB: Historically, we had M_ALIGN(), MH_ALIGN(), and MEXT_ALIGN() as
  919  * separate macros, each asserting that it was called at the proper moment.
  920  * This required callers to themselves test the storage type and call the
  921  * right one.  Rather than require callers to be aware of those layout
  922  * decisions, we centralize here.
  923  */
  924 static __inline void
  925 m_align(struct mbuf *m, int len)
  926 {
  927 #ifdef INVARIANTS
  928         const char *msg = "%s: not a virgin mbuf";
  929 #endif
  930         int adjust;
  931 
  932         KASSERT(m->m_data == M_START(m), (msg, __func__));
  933 
  934         adjust = M_SIZE(m) - len;
  935         m->m_data += adjust &~ (sizeof(long)-1);
  936 }
  937 
  938 #define M_ALIGN(m, len)         m_align(m, len)
  939 #define MH_ALIGN(m, len)        m_align(m, len)
  940 #define MEXT_ALIGN(m, len)      m_align(m, len)
  941 
  942 /*
  943  * Compute the amount of space available before the current start of data in
  944  * an mbuf.
  945  *
  946  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
  947  * of checking writability of the mbuf data area rests solely with the caller.
  948  *
  949  * NB: In previous versions, M_LEADINGSPACE() would only check M_WRITABLE()
  950  * for mbufs with external storage.  We now allow mbuf-embedded data to be
  951  * read-only as well.
  952  */
  953 #define M_LEADINGSPACE(m)                                               \
  954         (M_WRITABLE(m) ? ((m)->m_data - M_START(m)) : 0)
  955 
  956 /*
  957  * Compute the amount of space available after the end of data in an mbuf.
  958  *
  959  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
  960  * of checking writability of the mbuf data area rests solely with the caller.
  961  *
  962  * NB: In previous versions, M_TRAILINGSPACE() would only check M_WRITABLE()
  963  * for mbufs with external storage.  We now allow mbuf-embedded data to be
  964  * read-only as well.
  965  */
  966 #define M_TRAILINGSPACE(m)                                              \
  967         (M_WRITABLE(m) ?                                                \
  968             ((M_START(m) + M_SIZE(m)) - ((m)->m_data + (m)->m_len)) : 0)
  969 
  970 /*
  971  * Arrange to prepend space of size plen to mbuf m.  If a new mbuf must be
  972  * allocated, how specifies whether to wait.  If the allocation fails, the
  973  * original mbuf chain is freed and m is set to NULL.
  974  */
  975 #define M_PREPEND(m, plen, how) do {                                    \
  976         struct mbuf **_mmp = &(m);                                      \
  977         struct mbuf *_mm = *_mmp;                                       \
  978         int _mplen = (plen);                                            \
  979         int __mhow = (how);                                             \
  980                                                                         \
  981         MBUF_CHECKSLEEP(how);                                           \
  982         if (M_LEADINGSPACE(_mm) >= _mplen) {                            \
  983                 _mm->m_data -= _mplen;                                  \
  984                 _mm->m_len += _mplen;                                   \
  985         } else                                                          \
  986                 _mm = m_prepend(_mm, _mplen, __mhow);                   \
  987         if (_mm != NULL && _mm->m_flags & M_PKTHDR)                     \
  988                 _mm->m_pkthdr.len += _mplen;                            \
  989         *_mmp = _mm;                                                    \
  990 } while (0)
  991 
  992 /*
  993  * Change mbuf to new type.  This is a relatively expensive operation and
  994  * should be avoided.
  995  */
  996 #define MCHTYPE(m, t)   m_chtype((m), (t))
  997 
  998 /* Length to m_copy to copy all. */
  999 #define M_COPYALL       1000000000
 1000 
 1001 extern int              max_datalen;    /* MHLEN - max_hdr */
 1002 extern int              max_hdr;        /* Largest link + protocol header */
 1003 extern int              max_linkhdr;    /* Largest link-level header */
 1004 extern int              max_protohdr;   /* Largest protocol header */
 1005 extern int              nmbclusters;    /* Maximum number of clusters */
 1006 
 1007 /*-
 1008  * Network packets may have annotations attached by affixing a list of
 1009  * "packet tags" to the pkthdr structure.  Packet tags are dynamically
 1010  * allocated semi-opaque data structures that have a fixed header
 1011  * (struct m_tag) that specifies the size of the memory block and a
 1012  * <cookie,type> pair that identifies it.  The cookie is a 32-bit unique
 1013  * unsigned value used to identify a module or ABI.  By convention this value
 1014  * is chosen as the date+time that the module is created, expressed as the
 1015  * number of seconds since the epoch (e.g., using date -u +'%s').  The type
 1016  * value is an ABI/module-specific value that identifies a particular
 1017  * annotation and is private to the module.  For compatibility with systems
 1018  * like OpenBSD that define packet tags w/o an ABI/module cookie, the value
 1019  * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find
 1020  * compatibility shim functions and several tag types are defined below.
 1021  * Users that do not require compatibility should use a private cookie value
 1022  * so that packet tag-related definitions can be maintained privately.
 1023  *
 1024  * Note that the packet tag returned by m_tag_alloc has the default memory
 1025  * alignment implemented by malloc.  To reference private data one can use a
 1026  * construct like:
 1027  *
 1028  *      struct m_tag *mtag = m_tag_alloc(...);
 1029  *      struct foo *p = (struct foo *)(mtag+1);
 1030  *
 1031  * if the alignment of struct m_tag is sufficient for referencing members of
 1032  * struct foo.  Otherwise it is necessary to embed struct m_tag within the
 1033  * private data structure to insure proper alignment; e.g.,
 1034  *
 1035  *      struct foo {
 1036  *              struct m_tag    tag;
 1037  *              ...
 1038  *      };
 1039  *      struct foo *p = (struct foo *) m_tag_alloc(...);
 1040  *      struct m_tag *mtag = &p->tag;
 1041  */
 1042 
 1043 /*
 1044  * Persistent tags stay with an mbuf until the mbuf is reclaimed.  Otherwise
 1045  * tags are expected to ``vanish'' when they pass through a network
 1046  * interface.  For most interfaces this happens normally as the tags are
 1047  * reclaimed when the mbuf is free'd.  However in some special cases
 1048  * reclaiming must be done manually.  An example is packets that pass through
 1049  * the loopback interface.  Also, one must be careful to do this when
 1050  * ``turning around'' packets (e.g., icmp_reflect).
 1051  *
 1052  * To mark a tag persistent bit-or this flag in when defining the tag id.
 1053  * The tag will then be treated as described above.
 1054  */
 1055 #define MTAG_PERSISTENT                         0x800
 1056 
 1057 #define PACKET_TAG_NONE                         0  /* Nadda */
 1058 
 1059 /* Packet tags for use with PACKET_ABI_COMPAT. */
 1060 #define PACKET_TAG_IPSEC_IN_DONE                1  /* IPsec applied, in */
 1061 #define PACKET_TAG_IPSEC_OUT_DONE               2  /* IPsec applied, out */
 1062 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE         3  /* NIC IPsec crypto done */
 1063 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED      4  /* NIC IPsec crypto req'ed */
 1064 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO     5  /* NIC notifies IPsec */
 1065 #define PACKET_TAG_IPSEC_PENDING_TDB            6  /* Reminder to do IPsec */
 1066 #define PACKET_TAG_BRIDGE                       7  /* Bridge processing done */
 1067 #define PACKET_TAG_GIF                          8  /* GIF processing done */
 1068 #define PACKET_TAG_GRE                          9  /* GRE processing done */
 1069 #define PACKET_TAG_IN_PACKET_CHECKSUM           10 /* NIC checksumming done */
 1070 #define PACKET_TAG_ENCAP                        11 /* Encap.  processing */
 1071 #define PACKET_TAG_IPSEC_SOCKET                 12 /* IPSEC socket ref */
 1072 #define PACKET_TAG_IPSEC_HISTORY                13 /* IPSEC history */
 1073 #define PACKET_TAG_IPV6_INPUT                   14 /* IPV6 input processing */
 1074 #define PACKET_TAG_DUMMYNET                     15 /* dummynet info */
 1075 #define PACKET_TAG_DIVERT                       17 /* divert info */
 1076 #define PACKET_TAG_IPFORWARD                    18 /* ipforward info */
 1077 #define PACKET_TAG_MACLABEL     (19 | MTAG_PERSISTENT) /* MAC label */
 1078 #define PACKET_TAG_PF           (21 | MTAG_PERSISTENT) /* PF/ALTQ information */
 1079 #define PACKET_TAG_RTSOCKFAM                    25 /* rtsock sa family */
 1080 #define PACKET_TAG_IPOPTIONS                    27 /* Saved IP options */
 1081 #define PACKET_TAG_CARP                         28 /* CARP info */
 1082 #define PACKET_TAG_IPSEC_NAT_T_PORTS            29 /* two uint16_t */
 1083 #define PACKET_TAG_ND_OUTGOING                  30 /* ND outgoing */
 1084 
 1085 /* Specific cookies and tags. */
 1086 
 1087 /* Packet tag routines. */
 1088 struct m_tag    *m_tag_alloc(u_int32_t, int, int, int);
 1089 void             m_tag_delete(struct mbuf *, struct m_tag *);
 1090 void             m_tag_delete_chain(struct mbuf *, struct m_tag *);
 1091 void             m_tag_free_default(struct m_tag *);
 1092 struct m_tag    *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
 1093 struct m_tag    *m_tag_copy(struct m_tag *, int);
 1094 int              m_tag_copy_chain(struct mbuf *, const struct mbuf *, int);
 1095 void             m_tag_delete_nonpersistent(struct mbuf *);
 1096 
 1097 /*
 1098  * Initialize the list of tags associated with an mbuf.
 1099  */
 1100 static __inline void
 1101 m_tag_init(struct mbuf *m)
 1102 {
 1103 
 1104         SLIST_INIT(&m->m_pkthdr.tags);
 1105 }
 1106 
 1107 /*
 1108  * Set up the contents of a tag.  Note that this does not fill in the free
 1109  * method; the caller is expected to do that.
 1110  *
 1111  * XXX probably should be called m_tag_init, but that was already taken.
 1112  */
 1113 static __inline void
 1114 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
 1115 {
 1116 
 1117         t->m_tag_id = type;
 1118         t->m_tag_len = len;
 1119         t->m_tag_cookie = cookie;
 1120 }
 1121 
 1122 /*
 1123  * Reclaim resources associated with a tag.
 1124  */
 1125 static __inline void
 1126 m_tag_free(struct m_tag *t)
 1127 {
 1128 
 1129         (*t->m_tag_free)(t);
 1130 }
 1131 
 1132 /*
 1133  * Return the first tag associated with an mbuf.
 1134  */
 1135 static __inline struct m_tag *
 1136 m_tag_first(struct mbuf *m)
 1137 {
 1138 
 1139         return (SLIST_FIRST(&m->m_pkthdr.tags));
 1140 }
 1141 
 1142 /*
 1143  * Return the next tag in the list of tags associated with an mbuf.
 1144  */
 1145 static __inline struct m_tag *
 1146 m_tag_next(struct mbuf *m __unused, struct m_tag *t)
 1147 {
 1148 
 1149         return (SLIST_NEXT(t, m_tag_link));
 1150 }
 1151 
 1152 /*
 1153  * Prepend a tag to the list of tags associated with an mbuf.
 1154  */
 1155 static __inline void
 1156 m_tag_prepend(struct mbuf *m, struct m_tag *t)
 1157 {
 1158 
 1159         SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
 1160 }
 1161 
 1162 /*
 1163  * Unlink a tag from the list of tags associated with an mbuf.
 1164  */
 1165 static __inline void
 1166 m_tag_unlink(struct mbuf *m, struct m_tag *t)
 1167 {
 1168 
 1169         SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
 1170 }
 1171 
 1172 /* These are for OpenBSD compatibility. */
 1173 #define MTAG_ABI_COMPAT         0               /* compatibility ABI */
 1174 
 1175 static __inline struct m_tag *
 1176 m_tag_get(int type, int length, int wait)
 1177 {
 1178         return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait));
 1179 }
 1180 
 1181 static __inline struct m_tag *
 1182 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
 1183 {
 1184         return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL :
 1185             m_tag_locate(m, MTAG_ABI_COMPAT, type, start));
 1186 }
 1187 
 1188 static __inline struct mbuf *
 1189 m_free(struct mbuf *m)
 1190 {
 1191         struct mbuf *n = m->m_next;
 1192 
 1193         MBUF_PROBE1(m__free, m);
 1194         if ((m->m_flags & (M_PKTHDR|M_NOFREE)) == (M_PKTHDR|M_NOFREE))
 1195                 m_tag_delete_chain(m, NULL);
 1196         if (m->m_flags & M_EXT)
 1197                 mb_free_ext(m);
 1198         else if ((m->m_flags & M_NOFREE) == 0)
 1199                 uma_zfree(zone_mbuf, m);
 1200         return (n);
 1201 }
 1202 
 1203 static __inline int
 1204 rt_m_getfib(struct mbuf *m)
 1205 {
 1206         KASSERT(m->m_flags & M_PKTHDR , ("Attempt to get FIB from non header mbuf."));
 1207         return (m->m_pkthdr.fibnum);
 1208 }
 1209 
 1210 #define M_GETFIB(_m)   rt_m_getfib(_m)
 1211 
 1212 #define M_SETFIB(_m, _fib) do {                                         \
 1213         KASSERT((_m)->m_flags & M_PKTHDR, ("Attempt to set FIB on non header mbuf."));  \
 1214         ((_m)->m_pkthdr.fibnum) = (_fib);                               \
 1215 } while (0)
 1216 
 1217 /* flags passed as first argument for "m_ether_tcpip_hash()" */
 1218 #define MBUF_HASHFLAG_L2        (1 << 2)
 1219 #define MBUF_HASHFLAG_L3        (1 << 3)
 1220 #define MBUF_HASHFLAG_L4        (1 << 4)
 1221 
 1222 /* mbuf hashing helper routines */
 1223 uint32_t        m_ether_tcpip_hash_init(void);
 1224 uint32_t        m_ether_tcpip_hash(const uint32_t, const struct mbuf *, const uint32_t);
 1225 
 1226 #ifdef MBUF_PROFILING
 1227  void m_profile(struct mbuf *m);
 1228  #define M_PROFILE(m) m_profile(m)
 1229 #else
 1230  #define M_PROFILE(m)
 1231 #endif
 1232 
 1233 struct mbufq {
 1234         STAILQ_HEAD(, mbuf)     mq_head;
 1235         int                     mq_len;
 1236         int                     mq_maxlen;
 1237 };
 1238 
 1239 static inline void
 1240 mbufq_init(struct mbufq *mq, int maxlen)
 1241 {
 1242 
 1243         STAILQ_INIT(&mq->mq_head);
 1244         mq->mq_maxlen = maxlen;
 1245         mq->mq_len = 0;
 1246 }
 1247 
 1248 static inline struct mbuf *
 1249 mbufq_flush(struct mbufq *mq)
 1250 {
 1251         struct mbuf *m;
 1252 
 1253         m = STAILQ_FIRST(&mq->mq_head);
 1254         STAILQ_INIT(&mq->mq_head);
 1255         mq->mq_len = 0;
 1256         return (m);
 1257 }
 1258 
 1259 static inline void
 1260 mbufq_drain(struct mbufq *mq)
 1261 {
 1262         struct mbuf *m, *n;
 1263 
 1264         n = mbufq_flush(mq);
 1265         while ((m = n) != NULL) {
 1266                 n = STAILQ_NEXT(m, m_stailqpkt);
 1267                 m_freem(m);
 1268         }
 1269 }
 1270 
 1271 static inline struct mbuf *
 1272 mbufq_first(const struct mbufq *mq)
 1273 {
 1274 
 1275         return (STAILQ_FIRST(&mq->mq_head));
 1276 }
 1277 
 1278 static inline struct mbuf *
 1279 mbufq_last(const struct mbufq *mq)
 1280 {
 1281 
 1282         return (STAILQ_LAST(&mq->mq_head, mbuf, m_stailqpkt));
 1283 }
 1284 
 1285 static inline int
 1286 mbufq_full(const struct mbufq *mq)
 1287 {
 1288 
 1289         return (mq->mq_len >= mq->mq_maxlen);
 1290 }
 1291 
 1292 static inline int
 1293 mbufq_len(const struct mbufq *mq)
 1294 {
 1295 
 1296         return (mq->mq_len);
 1297 }
 1298 
 1299 static inline int
 1300 mbufq_enqueue(struct mbufq *mq, struct mbuf *m)
 1301 {
 1302 
 1303         if (mbufq_full(mq))
 1304                 return (ENOBUFS);
 1305         STAILQ_INSERT_TAIL(&mq->mq_head, m, m_stailqpkt);
 1306         mq->mq_len++;
 1307         return (0);
 1308 }
 1309 
 1310 static inline struct mbuf *
 1311 mbufq_dequeue(struct mbufq *mq)
 1312 {
 1313         struct mbuf *m;
 1314 
 1315         m = STAILQ_FIRST(&mq->mq_head);
 1316         if (m) {
 1317                 STAILQ_REMOVE_HEAD(&mq->mq_head, m_stailqpkt);
 1318                 m->m_nextpkt = NULL;
 1319                 mq->mq_len--;
 1320         }
 1321         return (m);
 1322 }
 1323 
 1324 static inline void
 1325 mbufq_prepend(struct mbufq *mq, struct mbuf *m)
 1326 {
 1327 
 1328         STAILQ_INSERT_HEAD(&mq->mq_head, m, m_stailqpkt);
 1329         mq->mq_len++;
 1330 }
 1331 
 1332 /*
 1333  * Note: this doesn't enforce the maximum list size for dst.
 1334  */
 1335 static inline void
 1336 mbufq_concat(struct mbufq *mq_dst, struct mbufq *mq_src)
 1337 {
 1338 
 1339         mq_dst->mq_len += mq_src->mq_len;
 1340         STAILQ_CONCAT(&mq_dst->mq_head, &mq_src->mq_head);
 1341         mq_src->mq_len = 0;
 1342 }
 1343 
 1344 #ifdef _SYS_TIMESPEC_H_
 1345 static inline void
 1346 mbuf_tstmp2timespec(struct mbuf *m, struct timespec *ts)
 1347 {
 1348 
 1349         KASSERT((m->m_flags & M_PKTHDR) != 0, ("mbuf %p no M_PKTHDR", m));
 1350         KASSERT((m->m_flags & M_TSTMP) != 0, ("mbuf %p no M_TSTMP", m));
 1351         ts->tv_sec = m->m_pkthdr.rcv_tstmp / 1000000000;
 1352         ts->tv_nsec = m->m_pkthdr.rcv_tstmp % 1000000000;
 1353 }
 1354 #endif
 1355 
 1356 #ifdef NETDUMP
 1357 /* Invoked from the netdump client code. */
 1358 void    netdump_mbuf_drain(void);
 1359 void    netdump_mbuf_dump(void);
 1360 void    netdump_mbuf_reinit(int nmbuf, int nclust, int clsize);
 1361 #endif
 1362 
 1363 #endif /* _KERNEL */
 1364 #endif /* !_SYS_MBUF_H_ */

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