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  * Copyright (c) 1982, 1986, 1988, 1993
    3  *      The Regents of the University of California.
    4  * All rights reserved.
    5  *
    6  * Redistribution and use in source and binary forms, with or without
    7  * modification, are permitted provided that the following conditions
    8  * are met:
    9  * 1. Redistributions of source code must retain the above copyright
   10  *    notice, this list of conditions and the following disclaimer.
   11  * 2. Redistributions in binary form must reproduce the above copyright
   12  *    notice, this list of conditions and the following disclaimer in the
   13  *    documentation and/or other materials provided with the distribution.
   14  * 3. Neither the name of the University nor the names of its contributors
   15  *    may be used to endorse or promote products derived from this software
   16  *    without specific prior written permission.
   17  *
   18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   28  * SUCH DAMAGE.
   29  *
   30  *      @(#)mbuf.h      8.5 (Berkeley) 2/19/95
   31  * $FreeBSD: releng/10.3/sys/sys/mbuf.h 282786 2015-05-12 00:27:20Z hiren $
   32  */
   33 
   34 #ifndef _SYS_MBUF_H_
   35 #define _SYS_MBUF_H_
   36 
   37 /* XXX: These includes suck. Sorry! */
   38 #include <sys/queue.h>
   39 #ifdef _KERNEL
   40 #include <sys/systm.h>
   41 #include <vm/uma.h>
   42 #ifdef WITNESS
   43 #include <sys/lock.h>
   44 #endif
   45 #endif
   46 
   47 /*
   48  * Mbufs are of a single size, MSIZE (sys/param.h), which includes overhead.
   49  * An mbuf may add a single "mbuf cluster" of size MCLBYTES (also in
   50  * sys/param.h), which has no additional overhead and is used instead of the
   51  * internal data area; this is done when at least MINCLSIZE of data must be
   52  * stored.  Additionally, it is possible to allocate a separate buffer
   53  * externally and attach it to the mbuf in a way similar to that of mbuf
   54  * clusters.
   55  *
   56  * NB: These calculation do not take actual compiler-induced alignment and
   57  * padding inside the complete struct mbuf into account.  Appropriate
   58  * attention is required when changing members of struct mbuf.
   59  *
   60  * MLEN is data length in a normal mbuf.
   61  * MHLEN is data length in an mbuf with pktheader.
   62  * MINCLSIZE is a smallest amount of data that should be put into cluster.
   63  */
   64 #define MLEN            ((int)(MSIZE - sizeof(struct m_hdr)))
   65 #define MHLEN           ((int)(MLEN - sizeof(struct pkthdr)))
   66 #define MINCLSIZE       (MHLEN + 1)
   67 
   68 #ifdef _KERNEL
   69 /*-
   70  * Macro for type conversion: convert mbuf pointer to data pointer of correct
   71  * type:
   72  *
   73  * mtod(m, t)   -- Convert mbuf pointer to data pointer of correct type.
   74  * mtodo(m, o) -- Same as above but with offset 'o' into data.
   75  */
   76 #define mtod(m, t)      ((t)((m)->m_data))
   77 #define mtodo(m, o)     ((void *)(((m)->m_data) + (o)))
   78 
   79 /*
   80  * Argument structure passed to UMA routines during mbuf and packet
   81  * allocations.
   82  */
   83 struct mb_args {
   84         int     flags;  /* Flags for mbuf being allocated */
   85         short   type;   /* Type of mbuf being allocated */
   86 };
   87 #endif /* _KERNEL */
   88 
   89 /*
   90  * Header present at the beginning of every mbuf.
   91  * Size ILP32: 24
   92  *       LP64: 32
   93  */
   94 struct m_hdr {
   95         struct mbuf     *mh_next;       /* next buffer in chain */
   96         struct mbuf     *mh_nextpkt;    /* next chain in queue/record */
   97         caddr_t          mh_data;       /* location of data */
   98         int32_t          mh_len;        /* amount of data in this mbuf */
   99         uint32_t         mh_type:8,     /* type of data in this mbuf */
  100                          mh_flags:24;   /* flags; see below */
  101 #if !defined(__LP64__)
  102         uint32_t         mh_pad;        /* pad for 64bit alignment */
  103 #endif
  104 };
  105 
  106 /*
  107  * Packet tag structure (see below for details).
  108  */
  109 struct m_tag {
  110         SLIST_ENTRY(m_tag)      m_tag_link;     /* List of packet tags */
  111         u_int16_t               m_tag_id;       /* Tag ID */
  112         u_int16_t               m_tag_len;      /* Length of data */
  113         u_int32_t               m_tag_cookie;   /* ABI/Module ID */
  114         void                    (*m_tag_free)(struct m_tag *);
  115 };
  116 
  117 /*
  118  * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
  119  * Size ILP32: 48
  120  *       LP64: 56
  121  */
  122 struct pkthdr {
  123         struct ifnet    *rcvif;         /* rcv interface */
  124         SLIST_HEAD(packet_tags, m_tag) tags; /* list of packet tags */
  125         int32_t          len;           /* total packet length */
  126 
  127         /* Layer crossing persistent information. */
  128         uint32_t         flowid;        /* packet's 4-tuple system */
  129         uint64_t         csum_flags;    /* checksum and offload features */
  130         uint16_t         fibnum;        /* this packet should use this fib */
  131         uint8_t          cosqos;        /* class/quality of service */
  132         uint8_t          rsstype;       /* hash type */
  133         uint8_t          l2hlen;        /* layer 2 header length */
  134         uint8_t          l3hlen;        /* layer 3 header length */
  135         uint8_t          l4hlen;        /* layer 4 header length */
  136         uint8_t          l5hlen;        /* layer 5 header length */
  137         union {
  138                 uint8_t  eigth[8];
  139                 uint16_t sixteen[4];
  140                 uint32_t thirtytwo[2];
  141                 uint64_t sixtyfour[1];
  142                 uintptr_t unintptr[1];
  143                 void    *ptr;
  144         } PH_per;
  145 
  146         /* Layer specific non-persistent local storage for reassembly, etc. */
  147         union {
  148                 uint8_t  eigth[8];
  149                 uint16_t sixteen[4];
  150                 uint32_t thirtytwo[2];
  151                 uint64_t sixtyfour[1];
  152                 uintptr_t unintptr[1];
  153                 void    *ptr;
  154         } PH_loc;
  155 };
  156 #define ether_vtag      PH_per.sixteen[0]
  157 #define PH_vt           PH_per
  158 #define vt_nrecs        sixteen[0]
  159 #define tso_segsz       PH_per.sixteen[1]
  160 #define csum_phsum      PH_per.sixteen[2]
  161 #define csum_data       PH_per.thirtytwo[1]
  162 
  163 /*
  164  * Description of external storage mapped into mbuf; valid only if M_EXT is
  165  * set.
  166  * Size ILP32: 28
  167  *       LP64: 48
  168  */
  169 struct m_ext {
  170         volatile u_int  *ref_cnt;       /* pointer to ref count info */
  171         caddr_t          ext_buf;       /* start of buffer */
  172         uint32_t         ext_size;      /* size of buffer, for ext_free */
  173         uint32_t         ext_type:8,    /* type of external storage */
  174                          ext_flags:24;  /* external storage mbuf flags */
  175         int             (*ext_free)     /* free routine if not the usual */
  176                             (struct mbuf *, void *, void *);
  177         void            *ext_arg1;      /* optional argument pointer */
  178         void            *ext_arg2;      /* optional argument pointer */
  179 };
  180 
  181 /*
  182  * The core of the mbuf object along with some shortcut defines for practical
  183  * purposes.
  184  */
  185 struct mbuf {
  186         struct m_hdr    m_hdr;
  187         union {
  188                 struct {
  189                         struct pkthdr   MH_pkthdr;      /* M_PKTHDR set */
  190                         union {
  191                                 struct m_ext    MH_ext; /* M_EXT set */
  192                                 char            MH_databuf[MHLEN];
  193                         } MH_dat;
  194                 } MH;
  195                 char    M_databuf[MLEN];                /* !M_PKTHDR, !M_EXT */
  196         } M_dat;
  197 };
  198 #define m_next          m_hdr.mh_next
  199 #define m_len           m_hdr.mh_len
  200 #define m_data          m_hdr.mh_data
  201 #define m_type          m_hdr.mh_type
  202 #define m_flags         m_hdr.mh_flags
  203 #define m_nextpkt       m_hdr.mh_nextpkt
  204 #define m_pkthdr        M_dat.MH.MH_pkthdr
  205 #define m_ext           M_dat.MH.MH_dat.MH_ext
  206 #define m_pktdat        M_dat.MH.MH_dat.MH_databuf
  207 #define m_dat           M_dat.M_databuf
  208 
  209 /* 
  210  * NOTE: forwards compatibility definitions for mbuf(9)
  211  *
  212  * These aren't 1:1 with the macros in r277203; in particular they're exposed
  213  * to both userland and kernel, whereas this is exposed to just _KERNEL -- to
  214  * avoid disruption with existing KBI/KPIs
  215  */
  216 #define MHSIZE          offsetof(struct mbuf, m_dat)
  217 #define MPKTHSIZE       offsetof(struct mbuf, m_pktdat)
  218 
  219 /*
  220  * mbuf flags of global significance and layer crossing.
  221  * Those of only protocol/layer specific significance are to be mapped
  222  * to M_PROTO[1-12] and cleared at layer handoff boundaries.
  223  * NB: Limited to the lower 24 bits.
  224  */
  225 #define M_EXT           0x00000001 /* has associated external storage */
  226 #define M_PKTHDR        0x00000002 /* start of record */
  227 #define M_EOR           0x00000004 /* end of record */
  228 #define M_RDONLY        0x00000008 /* associated data is marked read-only */
  229 #define M_BCAST         0x00000010 /* send/received as link-level broadcast */
  230 #define M_MCAST         0x00000020 /* send/received as link-level multicast */
  231 #define M_PROMISC       0x00000040 /* packet was not for us */
  232 #define M_VLANTAG       0x00000080 /* ether_vtag is valid */
  233 #define M_FLOWID        0x00000100 /* deprecated: flowid is valid */
  234 #define M_NOFREE        0x00000200 /* do not free mbuf, embedded in cluster */
  235 
  236 #define M_PROTO1        0x00001000 /* protocol-specific */
  237 #define M_PROTO2        0x00002000 /* protocol-specific */
  238 #define M_PROTO3        0x00004000 /* protocol-specific */
  239 #define M_PROTO4        0x00008000 /* protocol-specific */
  240 #define M_PROTO5        0x00010000 /* protocol-specific */
  241 #define M_PROTO6        0x00020000 /* protocol-specific */
  242 #define M_PROTO7        0x00040000 /* protocol-specific */
  243 #define M_PROTO8        0x00080000 /* protocol-specific */
  244 #define M_PROTO9        0x00100000 /* protocol-specific */
  245 #define M_PROTO10       0x00200000 /* protocol-specific */
  246 #define M_PROTO11       0x00400000 /* protocol-specific */
  247 #define M_PROTO12       0x00800000 /* protocol-specific */
  248 
  249 /*
  250  * Flags to purge when crossing layers.
  251  */
  252 #define M_PROTOFLAGS \
  253     (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8|\
  254      M_PROTO9|M_PROTO10|M_PROTO11|M_PROTO12)
  255 
  256 /*
  257  * Flags preserved when copying m_pkthdr.
  258  */
  259 #define M_COPYFLAGS \
  260     (M_PKTHDR|M_EOR|M_RDONLY|M_BCAST|M_MCAST|M_PROMISC|M_VLANTAG|M_FLOWID| \
  261      M_PROTOFLAGS)
  262 
  263 /*
  264  * Mbuf flag description for use with printf(9) %b identifier.
  265  */
  266 #define M_FLAG_BITS \
  267     "\2\1M_EXT\2M_PKTHDR\3M_EOR\4M_RDONLY\5M_BCAST\6M_MCAST" \
  268     "\7M_PROMISC\10M_VLANTAG\11M_FLOWID"
  269 #define M_FLAG_PROTOBITS \
  270     "\15M_PROTO1\16M_PROTO2\17M_PROTO3\20M_PROTO4\21M_PROTO5" \
  271     "\22M_PROTO6\23M_PROTO7\24M_PROTO8\25M_PROTO9\26M_PROTO10" \
  272     "\27M_PROTO11\30M_PROTO12"
  273 #define M_FLAG_PRINTF (M_FLAG_BITS M_FLAG_PROTOBITS)
  274 
  275 /*
  276  * Network interface cards are able to hash protocol fields (such as IPv4
  277  * addresses and TCP port numbers) classify packets into flows.  These flows
  278  * can then be used to maintain ordering while delivering packets to the OS
  279  * via parallel input queues, as well as to provide a stateless affinity
  280  * model.  NIC drivers can pass up the hash via m->m_pkthdr.flowid, and set
  281  * m_flag fields to indicate how the hash should be interpreted by the
  282  * network stack.
  283  *
  284  * Most NICs support RSS, which provides ordering and explicit affinity, and
  285  * use the hash m_flag bits to indicate what header fields were covered by
  286  * the hash.  M_HASHTYPE_OPAQUE can be set by non-RSS cards or configurations
  287  * that provide an opaque flow identifier, allowing for ordering and
  288  * distribution without explicit affinity.
  289  */
  290 #define M_HASHTYPE_NONE                 0
  291 #define M_HASHTYPE_RSS_IPV4             1       /* IPv4 2-tuple */
  292 #define M_HASHTYPE_RSS_TCP_IPV4         2       /* TCPv4 4-tuple */
  293 #define M_HASHTYPE_RSS_IPV6             3       /* IPv6 2-tuple */
  294 #define M_HASHTYPE_RSS_TCP_IPV6         4       /* TCPv6 4-tuple */
  295 #define M_HASHTYPE_RSS_IPV6_EX          5       /* IPv6 2-tuple + ext hdrs */
  296 #define M_HASHTYPE_RSS_TCP_IPV6_EX      6       /* TCPv6 4-tiple + ext hdrs */
  297 #define M_HASHTYPE_OPAQUE               255     /* ordering, not affinity */
  298 
  299 #define M_HASHTYPE_CLEAR(m)     ((m)->m_pkthdr.rsstype = 0)
  300 /*
  301  * Handle M_FLOWID for legacy drivers still using them.
  302  */
  303 #define M_HASHTYPE_GET(m)       (((m->m_flags & M_FLOWID) &&        \
  304     (m)->m_pkthdr.rsstype == M_HASHTYPE_NONE) ? M_HASHTYPE_OPAQUE : \
  305     (m)->m_pkthdr.rsstype)
  306 #define M_HASHTYPE_SET(m, v)    do {        \
  307             if ((v) != M_HASHTYPE_NONE)     \
  308                 m->m_flags |= M_FLOWID;     \
  309             (m)->m_pkthdr.rsstype = (v);    \
  310 } while (0)
  311 #define M_HASHTYPE_TEST(m, v)   (M_HASHTYPE_GET(m) == (v))
  312 
  313 /*
  314  * COS/QOS class and quality of service tags.
  315  * It uses DSCP code points as base.
  316  */
  317 #define QOS_DSCP_CS0            0x00
  318 #define QOS_DSCP_DEF            QOS_DSCP_CS0
  319 #define QOS_DSCP_CS1            0x20
  320 #define QOS_DSCP_AF11           0x28
  321 #define QOS_DSCP_AF12           0x30
  322 #define QOS_DSCP_AF13           0x38
  323 #define QOS_DSCP_CS2            0x40
  324 #define QOS_DSCP_AF21           0x48
  325 #define QOS_DSCP_AF22           0x50
  326 #define QOS_DSCP_AF23           0x58
  327 #define QOS_DSCP_CS3            0x60
  328 #define QOS_DSCP_AF31           0x68
  329 #define QOS_DSCP_AF32           0x70
  330 #define QOS_DSCP_AF33           0x78
  331 #define QOS_DSCP_CS4            0x80
  332 #define QOS_DSCP_AF41           0x88
  333 #define QOS_DSCP_AF42           0x90
  334 #define QOS_DSCP_AF43           0x98
  335 #define QOS_DSCP_CS5            0xa0
  336 #define QOS_DSCP_EF             0xb8
  337 #define QOS_DSCP_CS6            0xc0
  338 #define QOS_DSCP_CS7            0xe0
  339 
  340 /*
  341  * External mbuf storage buffer types.
  342  */
  343 #define EXT_CLUSTER     1       /* mbuf cluster */
  344 #define EXT_SFBUF       2       /* sendfile(2)'s sf_bufs */
  345 #define EXT_JUMBOP      3       /* jumbo cluster 4096 bytes */
  346 #define EXT_JUMBO9      4       /* jumbo cluster 9216 bytes */
  347 #define EXT_JUMBO16     5       /* jumbo cluster 16184 bytes */
  348 #define EXT_PACKET      6       /* mbuf+cluster from packet zone */
  349 #define EXT_MBUF        7       /* external mbuf reference (M_IOVEC) */
  350 
  351 #define EXT_VENDOR1     224     /* for vendor-internal use */
  352 #define EXT_VENDOR2     225     /* for vendor-internal use */
  353 #define EXT_VENDOR3     226     /* for vendor-internal use */
  354 #define EXT_VENDOR4     227     /* for vendor-internal use */
  355 
  356 #define EXT_EXP1        244     /* for experimental use */
  357 #define EXT_EXP2        245     /* for experimental use */
  358 #define EXT_EXP3        246     /* for experimental use */
  359 #define EXT_EXP4        247     /* for experimental use */
  360 
  361 #define EXT_NET_DRV     252     /* custom ext_buf provided by net driver(s) */
  362 #define EXT_MOD_TYPE    253     /* custom module's ext_buf type */
  363 #define EXT_DISPOSABLE  254     /* can throw this buffer away w/page flipping */
  364 #define EXT_EXTREF      255     /* has externally maintained ref_cnt ptr */
  365 
  366 /*
  367  * Flags for external mbuf buffer types.
  368  * NB: limited to the lower 24 bits.
  369  */
  370 #define EXT_FLAG_EMBREF         0x000001        /* embedded ref_cnt, notyet */
  371 #define EXT_FLAG_EXTREF         0x000002        /* external ref_cnt, notyet */
  372 #define EXT_FLAG_NOFREE         0x000010        /* don't free mbuf to pool, notyet */
  373 
  374 #define EXT_FLAG_VENDOR1        0x010000        /* for vendor-internal use */
  375 #define EXT_FLAG_VENDOR2        0x020000        /* for vendor-internal use */
  376 #define EXT_FLAG_VENDOR3        0x040000        /* for vendor-internal use */
  377 #define EXT_FLAG_VENDOR4        0x080000        /* for vendor-internal use */
  378 
  379 #define EXT_FLAG_EXP1           0x100000        /* for experimental use */
  380 #define EXT_FLAG_EXP2           0x200000        /* for experimental use */
  381 #define EXT_FLAG_EXP3           0x400000        /* for experimental use */
  382 #define EXT_FLAG_EXP4           0x800000        /* for experimental use */
  383 
  384 /*
  385  * EXT flag description for use with printf(9) %b identifier.
  386  */
  387 #define EXT_FLAG_BITS \
  388     "\2\1EXT_FLAG_EMBREF\2EXT_FLAG_EXTREF\5EXT_FLAG_NOFREE" \
  389     "\21EXT_FLAG_VENDOR1\22EXT_FLAG_VENDOR2\23EXT_FLAG_VENDOR3" \
  390     "\24EXT_FLAG_VENDOR4\25EXT_FLAG_EXP1\26EXT_FLAG_EXP2\27EXT_FLAG_EXP3" \
  391     "\30EXT_FLAG_EXP4"
  392 
  393 /*
  394  * Return values for (*ext_free).
  395  */
  396 #define EXT_FREE_OK     0       /* Normal return */
  397 
  398 /*
  399  * Flags indicating checksum, segmentation and other offload work to be
  400  * done, or already done, by hardware or lower layers.  It is split into
  401  * separate inbound and outbound flags.
  402  *
  403  * Outbound flags that are set by upper protocol layers requesting lower
  404  * layers, or ideally the hardware, to perform these offloading tasks.
  405  * For outbound packets this field and its flags can be directly tested
  406  * against if_data.ifi_hwassist.
  407  */
  408 #define CSUM_IP                 0x00000001      /* IP header checksum offload */
  409 #define CSUM_IP_UDP             0x00000002      /* UDP checksum offload */
  410 #define CSUM_IP_TCP             0x00000004      /* TCP checksum offload */
  411 #define CSUM_IP_SCTP            0x00000008      /* SCTP checksum offload */
  412 #define CSUM_IP_TSO             0x00000010      /* TCP segmentation offload */
  413 #define CSUM_IP_ISCSI           0x00000020      /* iSCSI checksum offload */
  414 
  415 #define CSUM_IP6_UDP            0x00000200      /* UDP checksum offload */
  416 #define CSUM_IP6_TCP            0x00000400      /* TCP checksum offload */
  417 #define CSUM_IP6_SCTP           0x00000800      /* SCTP checksum offload */
  418 #define CSUM_IP6_TSO            0x00001000      /* TCP segmentation offload */
  419 #define CSUM_IP6_ISCSI          0x00002000      /* iSCSI checksum offload */
  420 
  421 /* Inbound checksum support where the checksum was verified by hardware. */
  422 #define CSUM_L3_CALC            0x01000000      /* calculated layer 3 csum */
  423 #define CSUM_L3_VALID           0x02000000      /* checksum is correct */
  424 #define CSUM_L4_CALC            0x04000000      /* calculated layer 4 csum */
  425 #define CSUM_L4_VALID           0x08000000      /* checksum is correct */
  426 #define CSUM_L5_CALC            0x10000000      /* calculated layer 5 csum */
  427 #define CSUM_L5_VALID           0x20000000      /* checksum is correct */
  428 #define CSUM_COALESED           0x40000000      /* contains merged segments */
  429 
  430 /*
  431  * CSUM flag description for use with printf(9) %b identifier.
  432  */
  433 #define CSUM_BITS \
  434     "\2\1CSUM_IP\2CSUM_IP_UDP\3CSUM_IP_TCP\4CSUM_IP_SCTP\5CSUM_IP_TSO" \
  435     "\6CSUM_IP_ISCSI" \
  436     "\12CSUM_IP6_UDP\13CSUM_IP6_TCP\14CSUM_IP6_SCTP\15CSUM_IP6_TSO" \
  437     "\16CSUM_IP6_ISCSI" \
  438     "\31CSUM_L3_CALC\32CSUM_L3_VALID\33CSUM_L4_CALC\34CSUM_L4_VALID" \
  439     "\35CSUM_L5_CALC\36CSUM_L5_VALID\37CSUM_COALESED"
  440 
  441 /* CSUM flags compatibility mappings. */
  442 #define CSUM_IP_CHECKED         CSUM_L3_CALC
  443 #define CSUM_IP_VALID           CSUM_L3_VALID
  444 #define CSUM_DATA_VALID         CSUM_L4_VALID
  445 #define CSUM_PSEUDO_HDR         CSUM_L4_CALC
  446 #define CSUM_SCTP_VALID         CSUM_L4_VALID
  447 #define CSUM_DELAY_DATA         (CSUM_TCP|CSUM_UDP)
  448 #define CSUM_DELAY_IP           CSUM_IP         /* Only v4, no v6 IP hdr csum */
  449 #define CSUM_DELAY_DATA_IPV6    (CSUM_TCP_IPV6|CSUM_UDP_IPV6)
  450 #define CSUM_DATA_VALID_IPV6    CSUM_DATA_VALID
  451 #define CSUM_TCP                CSUM_IP_TCP
  452 #define CSUM_UDP                CSUM_IP_UDP
  453 #define CSUM_SCTP               CSUM_IP_SCTP
  454 #define CSUM_TSO                (CSUM_IP_TSO|CSUM_IP6_TSO)
  455 #define CSUM_UDP_IPV6           CSUM_IP6_UDP
  456 #define CSUM_TCP_IPV6           CSUM_IP6_TCP
  457 #define CSUM_SCTP_IPV6          CSUM_IP6_SCTP
  458 #define CSUM_FRAGMENT           0x0             /* Unused */
  459 
  460 /*
  461  * mbuf types describing the content of the mbuf (including external storage).
  462  */
  463 #define MT_NOTMBUF      0       /* USED INTERNALLY ONLY! Object is not mbuf */
  464 #define MT_DATA         1       /* dynamic (data) allocation */
  465 #define MT_HEADER       MT_DATA /* packet header, use M_PKTHDR instead */
  466 
  467 #define MT_VENDOR1      4       /* for vendor-internal use */
  468 #define MT_VENDOR2      5       /* for vendor-internal use */
  469 #define MT_VENDOR3      6       /* for vendor-internal use */
  470 #define MT_VENDOR4      7       /* for vendor-internal use */
  471 
  472 #define MT_SONAME       8       /* socket name */
  473 
  474 #define MT_EXP1         9       /* for experimental use */
  475 #define MT_EXP2         10      /* for experimental use */
  476 #define MT_EXP3         11      /* for experimental use */
  477 #define MT_EXP4         12      /* for experimental use */
  478 
  479 #define MT_CONTROL      14      /* extra-data protocol message */
  480 #define MT_OOBDATA      15      /* expedited data  */
  481 #define MT_NTYPES       16      /* number of mbuf types for mbtypes[] */
  482 
  483 #define MT_NOINIT       255     /* Not a type but a flag to allocate
  484                                    a non-initialized mbuf */
  485 
  486 /*
  487  * Compatibility with historic mbuf allocator.
  488  */
  489 #define MBTOM(how)      (how)
  490 #define M_DONTWAIT      M_NOWAIT
  491 #define M_TRYWAIT       M_WAITOK
  492 #define M_WAIT          M_WAITOK
  493 
  494 /*
  495  * String names of mbuf-related UMA(9) and malloc(9) types.  Exposed to
  496  * !_KERNEL so that monitoring tools can look up the zones with
  497  * libmemstat(3).
  498  */
  499 #define MBUF_MEM_NAME           "mbuf"
  500 #define MBUF_CLUSTER_MEM_NAME   "mbuf_cluster"
  501 #define MBUF_PACKET_MEM_NAME    "mbuf_packet"
  502 #define MBUF_JUMBOP_MEM_NAME    "mbuf_jumbo_page"
  503 #define MBUF_JUMBO9_MEM_NAME    "mbuf_jumbo_9k"
  504 #define MBUF_JUMBO16_MEM_NAME   "mbuf_jumbo_16k"
  505 #define MBUF_TAG_MEM_NAME       "mbuf_tag"
  506 #define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt"
  507 
  508 #ifdef _KERNEL
  509 
  510 #ifdef WITNESS
  511 #define MBUF_CHECKSLEEP(how) do {                                       \
  512         if (how == M_WAITOK)                                            \
  513                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,         \
  514                     "Sleeping in \"%s\"", __func__);                    \
  515 } while (0)
  516 #else
  517 #define MBUF_CHECKSLEEP(how)
  518 #endif
  519 
  520 /*
  521  * Network buffer allocation API
  522  *
  523  * The rest of it is defined in kern/kern_mbuf.c
  524  */
  525 extern uma_zone_t       zone_mbuf;
  526 extern uma_zone_t       zone_clust;
  527 extern uma_zone_t       zone_pack;
  528 extern uma_zone_t       zone_jumbop;
  529 extern uma_zone_t       zone_jumbo9;
  530 extern uma_zone_t       zone_jumbo16;
  531 extern uma_zone_t       zone_ext_refcnt;
  532 
  533 void             mb_free_ext(struct mbuf *);
  534 int              m_pkthdr_init(struct mbuf *, int);
  535 
  536 static __inline int
  537 m_gettype(int size)
  538 {
  539         int type;
  540 
  541         switch (size) {
  542         case MSIZE:
  543                 type = EXT_MBUF;
  544                 break;
  545         case MCLBYTES:
  546                 type = EXT_CLUSTER;
  547                 break;
  548 #if MJUMPAGESIZE != MCLBYTES
  549         case MJUMPAGESIZE:
  550                 type = EXT_JUMBOP;
  551                 break;
  552 #endif
  553         case MJUM9BYTES:
  554                 type = EXT_JUMBO9;
  555                 break;
  556         case MJUM16BYTES:
  557                 type = EXT_JUMBO16;
  558                 break;
  559         default:
  560                 panic("%s: invalid cluster size %d", __func__, size);
  561         }
  562 
  563         return (type);
  564 }
  565 
  566 /*
  567  * Associated an external reference counted buffer with an mbuf.
  568  */
  569 static __inline void
  570 m_extaddref(struct mbuf *m, caddr_t buf, u_int size, u_int *ref_cnt,
  571     int (*freef)(struct mbuf *, void *, void *), void *arg1, void *arg2)
  572 {
  573 
  574         KASSERT(ref_cnt != NULL, ("%s: ref_cnt not provided", __func__));
  575 
  576         atomic_add_int(ref_cnt, 1);
  577         m->m_flags |= M_EXT;
  578         m->m_ext.ext_buf = buf;
  579         m->m_ext.ref_cnt = ref_cnt;
  580         m->m_data = m->m_ext.ext_buf;
  581         m->m_ext.ext_size = size;
  582         m->m_ext.ext_free = freef;
  583         m->m_ext.ext_arg1 = arg1;
  584         m->m_ext.ext_arg2 = arg2;
  585         m->m_ext.ext_type = EXT_EXTREF;
  586         m->m_ext.ext_flags = 0;
  587 }
  588 
  589 static __inline uma_zone_t
  590 m_getzone(int size)
  591 {
  592         uma_zone_t zone;
  593 
  594         switch (size) {
  595         case MCLBYTES:
  596                 zone = zone_clust;
  597                 break;
  598 #if MJUMPAGESIZE != MCLBYTES
  599         case MJUMPAGESIZE:
  600                 zone = zone_jumbop;
  601                 break;
  602 #endif
  603         case MJUM9BYTES:
  604                 zone = zone_jumbo9;
  605                 break;
  606         case MJUM16BYTES:
  607                 zone = zone_jumbo16;
  608                 break;
  609         default:
  610                 panic("%s: invalid cluster size %d", __func__, size);
  611         }
  612 
  613         return (zone);
  614 }
  615 
  616 /*
  617  * Initialize an mbuf with linear storage.
  618  *
  619  * Inline because the consumer text overhead will be roughly the same to
  620  * initialize or call a function with this many parameters and M_PKTHDR
  621  * should go away with constant propagation for !MGETHDR.
  622  */
  623 static __inline int
  624 m_init(struct mbuf *m, uma_zone_t zone, int size, int how, short type,
  625     int flags)
  626 {
  627         int error;
  628 
  629         m->m_next = NULL;
  630         m->m_nextpkt = NULL;
  631         m->m_data = m->m_dat;
  632         m->m_len = 0;
  633         m->m_flags = flags;
  634         m->m_type = type;
  635         if (flags & M_PKTHDR) {
  636                 if ((error = m_pkthdr_init(m, how)) != 0)
  637                         return (error);
  638         }
  639 
  640         return (0);
  641 }
  642 
  643 static __inline struct mbuf *
  644 m_get(int how, short type)
  645 {
  646         struct mb_args args;
  647 
  648         args.flags = 0;
  649         args.type = type;
  650         return (uma_zalloc_arg(zone_mbuf, &args, how));
  651 }
  652 
  653 /*
  654  * XXX This should be deprecated, very little use.
  655  */
  656 static __inline struct mbuf *
  657 m_getclr(int how, short type)
  658 {
  659         struct mbuf *m;
  660         struct mb_args args;
  661 
  662         args.flags = 0;
  663         args.type = type;
  664         m = uma_zalloc_arg(zone_mbuf, &args, how);
  665         if (m != NULL)
  666                 bzero(m->m_data, MLEN);
  667         return (m);
  668 }
  669 
  670 static __inline struct mbuf *
  671 m_gethdr(int how, short type)
  672 {
  673         struct mb_args args;
  674 
  675         args.flags = M_PKTHDR;
  676         args.type = type;
  677         return (uma_zalloc_arg(zone_mbuf, &args, how));
  678 }
  679 
  680 static __inline struct mbuf *
  681 m_getcl(int how, short type, int flags)
  682 {
  683         struct mb_args args;
  684 
  685         args.flags = flags;
  686         args.type = type;
  687         return (uma_zalloc_arg(zone_pack, &args, how));
  688 }
  689 
  690 static __inline void
  691 m_clget(struct mbuf *m, int how)
  692 {
  693 
  694         if (m->m_flags & M_EXT)
  695                 printf("%s: %p mbuf already has cluster\n", __func__, m);
  696         m->m_ext.ext_buf = (char *)NULL;
  697         uma_zalloc_arg(zone_clust, m, how);
  698         /*
  699          * On a cluster allocation failure, drain the packet zone and retry,
  700          * we might be able to loosen a few clusters up on the drain.
  701          */
  702         if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) {
  703                 zone_drain(zone_pack);
  704                 uma_zalloc_arg(zone_clust, m, how);
  705         }
  706 }
  707 
  708 /*
  709  * m_cljget() is different from m_clget() as it can allocate clusters without
  710  * attaching them to an mbuf.  In that case the return value is the pointer
  711  * to the cluster of the requested size.  If an mbuf was specified, it gets
  712  * the cluster attached to it and the return value can be safely ignored.
  713  * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
  714  */
  715 static __inline void *
  716 m_cljget(struct mbuf *m, int how, int size)
  717 {
  718         uma_zone_t zone;
  719 
  720         if (m && m->m_flags & M_EXT)
  721                 printf("%s: %p mbuf already has cluster\n", __func__, m);
  722         if (m != NULL)
  723                 m->m_ext.ext_buf = NULL;
  724 
  725         zone = m_getzone(size);
  726         return (uma_zalloc_arg(zone, m, how));
  727 }
  728 
  729 static __inline void
  730 m_cljset(struct mbuf *m, void *cl, int type)
  731 {
  732         uma_zone_t zone;
  733         int size;
  734 
  735         switch (type) {
  736         case EXT_CLUSTER:
  737                 size = MCLBYTES;
  738                 zone = zone_clust;
  739                 break;
  740 #if MJUMPAGESIZE != MCLBYTES
  741         case EXT_JUMBOP:
  742                 size = MJUMPAGESIZE;
  743                 zone = zone_jumbop;
  744                 break;
  745 #endif
  746         case EXT_JUMBO9:
  747                 size = MJUM9BYTES;
  748                 zone = zone_jumbo9;
  749                 break;
  750         case EXT_JUMBO16:
  751                 size = MJUM16BYTES;
  752                 zone = zone_jumbo16;
  753                 break;
  754         default:
  755                 panic("%s: unknown cluster type %d", __func__, type);
  756                 break;
  757         }
  758 
  759         m->m_data = m->m_ext.ext_buf = cl;
  760         m->m_ext.ext_free = m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
  761         m->m_ext.ext_size = size;
  762         m->m_ext.ext_type = type;
  763         m->m_ext.ext_flags = 0;
  764         m->m_ext.ref_cnt = uma_find_refcnt(zone, cl);
  765         m->m_flags |= M_EXT;
  766 
  767 }
  768 
  769 static __inline void
  770 m_chtype(struct mbuf *m, short new_type)
  771 {
  772 
  773         m->m_type = new_type;
  774 }
  775 
  776 static __inline void
  777 m_clrprotoflags(struct mbuf *m)
  778 {
  779 
  780         m->m_flags &= ~M_PROTOFLAGS;
  781 }
  782 
  783 static __inline struct mbuf *
  784 m_last(struct mbuf *m)
  785 {
  786 
  787         while (m->m_next)
  788                 m = m->m_next;
  789         return (m);
  790 }
  791 
  792 /*
  793  * mbuf, cluster, and external object allocation macros (for compatibility
  794  * purposes).
  795  */
  796 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from))
  797 #define MGET(m, how, type)      ((m) = m_get((how), (type)))
  798 #define MGETHDR(m, how, type)   ((m) = m_gethdr((how), (type)))
  799 #define MCLGET(m, how)          m_clget((m), (how))
  800 #define MEXTADD(m, buf, size, free, arg1, arg2, flags, type)            \
  801     (void )m_extadd((m), (caddr_t)(buf), (size), (free), (arg1), (arg2),\
  802     (flags), (type), M_NOWAIT)
  803 #define m_getm(m, len, how, type)                                       \
  804     m_getm2((m), (len), (how), (type), M_PKTHDR)
  805 
  806 /*
  807  * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can
  808  * be both the local data payload, or an external buffer area, depending on
  809  * whether M_EXT is set).
  810  */
  811 #define M_WRITABLE(m)   (!((m)->m_flags & M_RDONLY) &&                  \
  812                          (!(((m)->m_flags & M_EXT)) ||                  \
  813                          (*((m)->m_ext.ref_cnt) == 1)) )                \
  814 
  815 /* Check if the supplied mbuf has a packet header, or else panic. */
  816 #define M_ASSERTPKTHDR(m)                                               \
  817         KASSERT((m) != NULL && (m)->m_flags & M_PKTHDR,                 \
  818             ("%s: no mbuf packet header!", __func__))
  819 
  820 /*
  821  * Ensure that the supplied mbuf is a valid, non-free mbuf.
  822  *
  823  * XXX: Broken at the moment.  Need some UMA magic to make it work again.
  824  */
  825 #define M_ASSERTVALID(m)                                                \
  826         KASSERT((((struct mbuf *)m)->m_flags & 0) == 0,                 \
  827             ("%s: attempted use of a free mbuf!", __func__))
  828 
  829 /*
  830  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an
  831  * object of the specified size at the end of the mbuf, longword aligned.
  832  */
  833 #define M_ALIGN(m, len) do {                                            \
  834         KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)),                     \
  835                 ("%s: M_ALIGN not normal mbuf", __func__));             \
  836         KASSERT((m)->m_data == (m)->m_dat,                              \
  837                 ("%s: M_ALIGN not a virgin mbuf", __func__));           \
  838         (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1);            \
  839 } while (0)
  840 
  841 /*
  842  * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by
  843  * M_DUP/MOVE_PKTHDR.
  844  */
  845 #define MH_ALIGN(m, len) do {                                           \
  846         KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT),     \
  847                 ("%s: MH_ALIGN not PKTHDR mbuf", __func__));            \
  848         KASSERT((m)->m_data == (m)->m_pktdat,                           \
  849                 ("%s: MH_ALIGN not a virgin mbuf", __func__));          \
  850         (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1);           \
  851 } while (0)
  852 
  853 /*
  854  * As above, for mbuf with external storage.
  855  */
  856 #define MEXT_ALIGN(m, len) do {                                         \
  857         KASSERT((m)->m_flags & M_EXT,                                   \
  858                 ("%s: MEXT_ALIGN not an M_EXT mbuf", __func__));        \
  859         KASSERT((m)->m_data == (m)->m_ext.ext_buf,                      \
  860                 ("%s: MEXT_ALIGN not a virgin mbuf", __func__));        \
  861         (m)->m_data += ((m)->m_ext.ext_size - (len)) &                  \
  862             ~(sizeof(long) - 1);                                        \
  863 } while (0)
  864 
  865 /*
  866  * Compute the amount of space available before the current start of data in
  867  * an mbuf.
  868  *
  869  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
  870  * of checking writability of the mbuf data area rests solely with the caller.
  871  */
  872 #define M_LEADINGSPACE(m)                                               \
  873         ((m)->m_flags & M_EXT ?                                         \
  874             (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0):     \
  875             (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat :     \
  876             (m)->m_data - (m)->m_dat)
  877 
  878 /*
  879  * Compute the amount of space available after the end of data in an mbuf.
  880  *
  881  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
  882  * of checking writability of the mbuf data area rests solely with the caller.
  883  */
  884 #define M_TRAILINGSPACE(m)                                              \
  885         ((m)->m_flags & M_EXT ?                                         \
  886             (M_WRITABLE(m) ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size   \
  887                 - ((m)->m_data + (m)->m_len) : 0) :                     \
  888             &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
  889 
  890 /*
  891  * Arrange to prepend space of size plen to mbuf m.  If a new mbuf must be
  892  * allocated, how specifies whether to wait.  If the allocation fails, the
  893  * original mbuf chain is freed and m is set to NULL.
  894  */
  895 #define M_PREPEND(m, plen, how) do {                                    \
  896         struct mbuf **_mmp = &(m);                                      \
  897         struct mbuf *_mm = *_mmp;                                       \
  898         int _mplen = (plen);                                            \
  899         int __mhow = (how);                                             \
  900                                                                         \
  901         MBUF_CHECKSLEEP(how);                                           \
  902         if (M_LEADINGSPACE(_mm) >= _mplen) {                            \
  903                 _mm->m_data -= _mplen;                                  \
  904                 _mm->m_len += _mplen;                                   \
  905         } else                                                          \
  906                 _mm = m_prepend(_mm, _mplen, __mhow);                   \
  907         if (_mm != NULL && _mm->m_flags & M_PKTHDR)                     \
  908                 _mm->m_pkthdr.len += _mplen;                            \
  909         *_mmp = _mm;                                                    \
  910 } while (0)
  911 
  912 /*
  913  * Change mbuf to new type.  This is a relatively expensive operation and
  914  * should be avoided.
  915  */
  916 #define MCHTYPE(m, t)   m_chtype((m), (t))
  917 
  918 /* Length to m_copy to copy all. */
  919 #define M_COPYALL       1000000000
  920 
  921 /* Compatibility with 4.3. */
  922 #define m_copy(m, o, l) m_copym((m), (o), (l), M_NOWAIT)
  923 
  924 extern int              max_datalen;    /* MHLEN - max_hdr */
  925 extern int              max_hdr;        /* Largest link + protocol header */
  926 extern int              max_linkhdr;    /* Largest link-level header */
  927 extern int              max_protohdr;   /* Largest protocol header */
  928 extern int              nmbclusters;    /* Maximum number of clusters */
  929 
  930 struct uio;
  931 
  932 void             m_adj(struct mbuf *, int);
  933 void             m_align(struct mbuf *, int);
  934 int              m_apply(struct mbuf *, int, int,
  935                     int (*)(void *, void *, u_int), void *);
  936 int              m_append(struct mbuf *, int, c_caddr_t);
  937 void             m_cat(struct mbuf *, struct mbuf *);
  938 int              m_extadd(struct mbuf *, caddr_t, u_int,
  939                     int (*)(struct mbuf *, void *, void *), void *, void *,
  940                     int, int, int);
  941 struct mbuf     *m_collapse(struct mbuf *, int, int);
  942 void             m_copyback(struct mbuf *, int, int, c_caddr_t);
  943 void             m_copydata(const struct mbuf *, int, int, caddr_t);
  944 struct mbuf     *m_copym(struct mbuf *, int, int, int);
  945 struct mbuf     *m_copymdata(struct mbuf *, struct mbuf *,
  946                     int, int, int, int);
  947 struct mbuf     *m_copypacket(struct mbuf *, int);
  948 void             m_copy_pkthdr(struct mbuf *, struct mbuf *);
  949 struct mbuf     *m_copyup(struct mbuf *, int, int);
  950 struct mbuf     *m_defrag(struct mbuf *, int);
  951 void             m_demote(struct mbuf *, int);
  952 struct mbuf     *m_devget(char *, int, int, struct ifnet *,
  953                     void (*)(char *, caddr_t, u_int));
  954 struct mbuf     *m_dup(struct mbuf *, int);
  955 int              m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
  956 u_int            m_fixhdr(struct mbuf *);
  957 struct mbuf     *m_fragment(struct mbuf *, int, int);
  958 void             m_freem(struct mbuf *);
  959 struct mbuf     *m_get2(int, int, short, int);
  960 struct mbuf     *m_getjcl(int, short, int, int);
  961 struct mbuf     *m_getm2(struct mbuf *, int, int, short, int);
  962 struct mbuf     *m_getptr(struct mbuf *, int, int *);
  963 u_int            m_length(struct mbuf *, struct mbuf **);
  964 int              m_mbuftouio(struct uio *, struct mbuf *, int);
  965 void             m_move_pkthdr(struct mbuf *, struct mbuf *);
  966 struct mbuf     *m_prepend(struct mbuf *, int, int);
  967 void             m_print(const struct mbuf *, int);
  968 struct mbuf     *m_pulldown(struct mbuf *, int, int, int *);
  969 struct mbuf     *m_pullup(struct mbuf *, int);
  970 int              m_sanity(struct mbuf *, int);
  971 struct mbuf     *m_split(struct mbuf *, int, int);
  972 struct mbuf     *m_uiotombuf(struct uio *, int, int, int, int);
  973 struct mbuf     *m_unshare(struct mbuf *, int);
  974 
  975 /*-
  976  * Network packets may have annotations attached by affixing a list of
  977  * "packet tags" to the pkthdr structure.  Packet tags are dynamically
  978  * allocated semi-opaque data structures that have a fixed header
  979  * (struct m_tag) that specifies the size of the memory block and a
  980  * <cookie,type> pair that identifies it.  The cookie is a 32-bit unique
  981  * unsigned value used to identify a module or ABI.  By convention this value
  982  * is chosen as the date+time that the module is created, expressed as the
  983  * number of seconds since the epoch (e.g., using date -u +'%s').  The type
  984  * value is an ABI/module-specific value that identifies a particular
  985  * annotation and is private to the module.  For compatibility with systems
  986  * like OpenBSD that define packet tags w/o an ABI/module cookie, the value
  987  * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find
  988  * compatibility shim functions and several tag types are defined below.
  989  * Users that do not require compatibility should use a private cookie value
  990  * so that packet tag-related definitions can be maintained privately.
  991  *
  992  * Note that the packet tag returned by m_tag_alloc has the default memory
  993  * alignment implemented by malloc.  To reference private data one can use a
  994  * construct like:
  995  *
  996  *      struct m_tag *mtag = m_tag_alloc(...);
  997  *      struct foo *p = (struct foo *)(mtag+1);
  998  *
  999  * if the alignment of struct m_tag is sufficient for referencing members of
 1000  * struct foo.  Otherwise it is necessary to embed struct m_tag within the
 1001  * private data structure to insure proper alignment; e.g.,
 1002  *
 1003  *      struct foo {
 1004  *              struct m_tag    tag;
 1005  *              ...
 1006  *      };
 1007  *      struct foo *p = (struct foo *) m_tag_alloc(...);
 1008  *      struct m_tag *mtag = &p->tag;
 1009  */
 1010 
 1011 /*
 1012  * Persistent tags stay with an mbuf until the mbuf is reclaimed.  Otherwise
 1013  * tags are expected to ``vanish'' when they pass through a network
 1014  * interface.  For most interfaces this happens normally as the tags are
 1015  * reclaimed when the mbuf is free'd.  However in some special cases
 1016  * reclaiming must be done manually.  An example is packets that pass through
 1017  * the loopback interface.  Also, one must be careful to do this when
 1018  * ``turning around'' packets (e.g., icmp_reflect).
 1019  *
 1020  * To mark a tag persistent bit-or this flag in when defining the tag id.
 1021  * The tag will then be treated as described above.
 1022  */
 1023 #define MTAG_PERSISTENT                         0x800
 1024 
 1025 #define PACKET_TAG_NONE                         0  /* Nadda */
 1026 
 1027 /* Packet tags for use with PACKET_ABI_COMPAT. */
 1028 #define PACKET_TAG_IPSEC_IN_DONE                1  /* IPsec applied, in */
 1029 #define PACKET_TAG_IPSEC_OUT_DONE               2  /* IPsec applied, out */
 1030 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE         3  /* NIC IPsec crypto done */
 1031 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED      4  /* NIC IPsec crypto req'ed */
 1032 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO     5  /* NIC notifies IPsec */
 1033 #define PACKET_TAG_IPSEC_PENDING_TDB            6  /* Reminder to do IPsec */
 1034 #define PACKET_TAG_BRIDGE                       7  /* Bridge processing done */
 1035 #define PACKET_TAG_GIF                          8  /* GIF processing done */
 1036 #define PACKET_TAG_GRE                          9  /* GRE processing done */
 1037 #define PACKET_TAG_IN_PACKET_CHECKSUM           10 /* NIC checksumming done */
 1038 #define PACKET_TAG_ENCAP                        11 /* Encap.  processing */
 1039 #define PACKET_TAG_IPSEC_SOCKET                 12 /* IPSEC socket ref */
 1040 #define PACKET_TAG_IPSEC_HISTORY                13 /* IPSEC history */
 1041 #define PACKET_TAG_IPV6_INPUT                   14 /* IPV6 input processing */
 1042 #define PACKET_TAG_DUMMYNET                     15 /* dummynet info */
 1043 #define PACKET_TAG_DIVERT                       17 /* divert info */
 1044 #define PACKET_TAG_IPFORWARD                    18 /* ipforward info */
 1045 #define PACKET_TAG_MACLABEL     (19 | MTAG_PERSISTENT) /* MAC label */
 1046 #define PACKET_TAG_PF           (21 | MTAG_PERSISTENT) /* PF/ALTQ information */
 1047 #define PACKET_TAG_RTSOCKFAM                    25 /* rtsock sa family */
 1048 #define PACKET_TAG_IPOPTIONS                    27 /* Saved IP options */
 1049 #define PACKET_TAG_CARP                         28 /* CARP info */
 1050 #define PACKET_TAG_IPSEC_NAT_T_PORTS            29 /* two uint16_t */
 1051 #define PACKET_TAG_ND_OUTGOING                  30 /* ND outgoing */
 1052 
 1053 /* Specific cookies and tags. */
 1054 
 1055 /* Packet tag routines. */
 1056 struct m_tag    *m_tag_alloc(u_int32_t, int, int, int);
 1057 void             m_tag_delete(struct mbuf *, struct m_tag *);
 1058 void             m_tag_delete_chain(struct mbuf *, struct m_tag *);
 1059 void             m_tag_free_default(struct m_tag *);
 1060 struct m_tag    *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
 1061 struct m_tag    *m_tag_copy(struct m_tag *, int);
 1062 int              m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
 1063 void             m_tag_delete_nonpersistent(struct mbuf *);
 1064 
 1065 /*
 1066  * Initialize the list of tags associated with an mbuf.
 1067  */
 1068 static __inline void
 1069 m_tag_init(struct mbuf *m)
 1070 {
 1071 
 1072         SLIST_INIT(&m->m_pkthdr.tags);
 1073 }
 1074 
 1075 /*
 1076  * Set up the contents of a tag.  Note that this does not fill in the free
 1077  * method; the caller is expected to do that.
 1078  *
 1079  * XXX probably should be called m_tag_init, but that was already taken.
 1080  */
 1081 static __inline void
 1082 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
 1083 {
 1084 
 1085         t->m_tag_id = type;
 1086         t->m_tag_len = len;
 1087         t->m_tag_cookie = cookie;
 1088 }
 1089 
 1090 /*
 1091  * Reclaim resources associated with a tag.
 1092  */
 1093 static __inline void
 1094 m_tag_free(struct m_tag *t)
 1095 {
 1096 
 1097         (*t->m_tag_free)(t);
 1098 }
 1099 
 1100 /*
 1101  * Return the first tag associated with an mbuf.
 1102  */
 1103 static __inline struct m_tag *
 1104 m_tag_first(struct mbuf *m)
 1105 {
 1106 
 1107         return (SLIST_FIRST(&m->m_pkthdr.tags));
 1108 }
 1109 
 1110 /*
 1111  * Return the next tag in the list of tags associated with an mbuf.
 1112  */
 1113 static __inline struct m_tag *
 1114 m_tag_next(struct mbuf *m, struct m_tag *t)
 1115 {
 1116 
 1117         return (SLIST_NEXT(t, m_tag_link));
 1118 }
 1119 
 1120 /*
 1121  * Prepend a tag to the list of tags associated with an mbuf.
 1122  */
 1123 static __inline void
 1124 m_tag_prepend(struct mbuf *m, struct m_tag *t)
 1125 {
 1126 
 1127         SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
 1128 }
 1129 
 1130 /*
 1131  * Unlink a tag from the list of tags associated with an mbuf.
 1132  */
 1133 static __inline void
 1134 m_tag_unlink(struct mbuf *m, struct m_tag *t)
 1135 {
 1136 
 1137         SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
 1138 }
 1139 
 1140 /* These are for OpenBSD compatibility. */
 1141 #define MTAG_ABI_COMPAT         0               /* compatibility ABI */
 1142 
 1143 static __inline struct m_tag *
 1144 m_tag_get(int type, int length, int wait)
 1145 {
 1146         return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait));
 1147 }
 1148 
 1149 static __inline struct m_tag *
 1150 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
 1151 {
 1152         return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL :
 1153             m_tag_locate(m, MTAG_ABI_COMPAT, type, start));
 1154 }
 1155 
 1156 static __inline struct mbuf *
 1157 m_free(struct mbuf *m)
 1158 {
 1159         struct mbuf *n = m->m_next;
 1160 
 1161         if ((m->m_flags & (M_PKTHDR|M_NOFREE)) == (M_PKTHDR|M_NOFREE))
 1162                 m_tag_delete_chain(m, NULL);
 1163         if (m->m_flags & M_EXT)
 1164                 mb_free_ext(m);
 1165         else if ((m->m_flags & M_NOFREE) == 0)
 1166                 uma_zfree(zone_mbuf, m);
 1167         return (n);
 1168 }
 1169 
 1170 static int inline
 1171 rt_m_getfib(struct mbuf *m)
 1172 {
 1173         KASSERT(m->m_flags & M_PKTHDR , ("Attempt to get FIB from non header mbuf."));
 1174         return (m->m_pkthdr.fibnum);
 1175 }
 1176 
 1177 #define M_GETFIB(_m)   rt_m_getfib(_m)
 1178 
 1179 #define M_SETFIB(_m, _fib) do {                                         \
 1180         KASSERT((_m)->m_flags & M_PKTHDR, ("Attempt to set FIB on non header mbuf."));  \
 1181         ((_m)->m_pkthdr.fibnum) = (_fib);                               \
 1182 } while (0)
 1183 
 1184 #endif /* _KERNEL */
 1185 
 1186 #ifdef MBUF_PROFILING
 1187  void m_profile(struct mbuf *m);
 1188  #define M_PROFILE(m) m_profile(m)
 1189 #else
 1190  #define M_PROFILE(m)
 1191 #endif
 1192 
 1193 
 1194 #endif /* !_SYS_MBUF_H_ */

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