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: head/sys/sys/mbuf.h 275329 2014-11-30 13:24:21Z glebius $
   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  eight[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  eight[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 #define pkt_tcphdr      PH_loc.ptr
  163 
  164 /*
  165  * Description of external storage mapped into mbuf; valid only if M_EXT is
  166  * set.
  167  * Size ILP32: 28
  168  *       LP64: 48
  169  */
  170 struct m_ext {
  171         volatile u_int  *ext_cnt;       /* pointer to ref count info */
  172         caddr_t          ext_buf;       /* start of buffer */
  173         uint32_t         ext_size;      /* size of buffer, for ext_free */
  174         uint32_t         ext_type:8,    /* type of external storage */
  175                          ext_flags:24;  /* external storage mbuf flags */
  176         void            (*ext_free)     /* free routine if not the usual */
  177                             (struct mbuf *, void *, void *);
  178         void            *ext_arg1;      /* optional argument pointer */
  179         void            *ext_arg2;      /* optional argument pointer */
  180 };
  181 
  182 /*
  183  * The core of the mbuf object along with some shortcut defines for practical
  184  * purposes.
  185  */
  186 struct mbuf {
  187         struct m_hdr    m_hdr;
  188         union {
  189                 struct {
  190                         struct pkthdr   MH_pkthdr;      /* M_PKTHDR set */
  191                         union {
  192                                 struct m_ext    MH_ext; /* M_EXT set */
  193                                 char            MH_databuf[MHLEN];
  194                         } MH_dat;
  195                 } MH;
  196                 char    M_databuf[MLEN];                /* !M_PKTHDR, !M_EXT */
  197         } M_dat;
  198 };
  199 #define m_next          m_hdr.mh_next
  200 #define m_len           m_hdr.mh_len
  201 #define m_data          m_hdr.mh_data
  202 #define m_type          m_hdr.mh_type
  203 #define m_flags         m_hdr.mh_flags
  204 #define m_nextpkt       m_hdr.mh_nextpkt
  205 #define m_pkthdr        M_dat.MH.MH_pkthdr
  206 #define m_ext           M_dat.MH.MH_dat.MH_ext
  207 #define m_pktdat        M_dat.MH.MH_dat.MH_databuf
  208 #define m_dat           M_dat.M_databuf
  209 
  210 /*
  211  * mbuf flags of global significance and layer crossing.
  212  * Those of only protocol/layer specific significance are to be mapped
  213  * to M_PROTO[1-12] and cleared at layer handoff boundaries.
  214  * NB: Limited to the lower 24 bits.
  215  */
  216 #define M_EXT           0x00000001 /* has associated external storage */
  217 #define M_PKTHDR        0x00000002 /* start of record */
  218 #define M_EOR           0x00000004 /* end of record */
  219 #define M_RDONLY        0x00000008 /* associated data is marked read-only */
  220 #define M_BCAST         0x00000010 /* send/received as link-level broadcast */
  221 #define M_MCAST         0x00000020 /* send/received as link-level multicast */
  222 #define M_PROMISC       0x00000040 /* packet was not for us */
  223 #define M_VLANTAG       0x00000080 /* ether_vtag is valid */
  224 #define M_FLOWID        0x00000100 /* deprecated: flowid is valid */
  225 #define M_NOFREE        0x00000200 /* do not free mbuf, embedded in cluster */
  226 
  227 #define M_PROTO1        0x00001000 /* protocol-specific */
  228 #define M_PROTO2        0x00002000 /* protocol-specific */
  229 #define M_PROTO3        0x00004000 /* protocol-specific */
  230 #define M_PROTO4        0x00008000 /* protocol-specific */
  231 #define M_PROTO5        0x00010000 /* protocol-specific */
  232 #define M_PROTO6        0x00020000 /* protocol-specific */
  233 #define M_PROTO7        0x00040000 /* protocol-specific */
  234 #define M_PROTO8        0x00080000 /* protocol-specific */
  235 #define M_PROTO9        0x00100000 /* protocol-specific */
  236 #define M_PROTO10       0x00200000 /* protocol-specific */
  237 #define M_PROTO11       0x00400000 /* protocol-specific */
  238 #define M_PROTO12       0x00800000 /* protocol-specific */
  239 
  240 /*
  241  * Flags to purge when crossing layers.
  242  */
  243 #define M_PROTOFLAGS \
  244     (M_PROTO1|M_PROTO2|M_PROTO3|M_PROTO4|M_PROTO5|M_PROTO6|M_PROTO7|M_PROTO8|\
  245      M_PROTO9|M_PROTO10|M_PROTO11|M_PROTO12)
  246 
  247 /*
  248  * Flags preserved when copying m_pkthdr.
  249  */
  250 #define M_COPYFLAGS \
  251     (M_PKTHDR|M_EOR|M_RDONLY|M_BCAST|M_MCAST|M_PROMISC|M_VLANTAG|M_FLOWID| \
  252      M_PROTOFLAGS)
  253 
  254 /*
  255  * Mbuf flag description for use with printf(9) %b identifier.
  256  */
  257 #define M_FLAG_BITS \
  258     "\2\1M_EXT\2M_PKTHDR\3M_EOR\4M_RDONLY\5M_BCAST\6M_MCAST" \
  259     "\7M_PROMISC\10M_VLANTAG\11M_FLOWID"
  260 #define M_FLAG_PROTOBITS \
  261     "\15M_PROTO1\16M_PROTO2\17M_PROTO3\20M_PROTO4\21M_PROTO5" \
  262     "\22M_PROTO6\23M_PROTO7\24M_PROTO8\25M_PROTO9\26M_PROTO10" \
  263     "\27M_PROTO11\30M_PROTO12"
  264 #define M_FLAG_PRINTF (M_FLAG_BITS M_FLAG_PROTOBITS)
  265 
  266 /*
  267  * Network interface cards are able to hash protocol fields (such as IPv4
  268  * addresses and TCP port numbers) classify packets into flows.  These flows
  269  * can then be used to maintain ordering while delivering packets to the OS
  270  * via parallel input queues, as well as to provide a stateless affinity
  271  * model.  NIC drivers can pass up the hash via m->m_pkthdr.flowid, and set
  272  * m_flag fields to indicate how the hash should be interpreted by the
  273  * network stack.
  274  *
  275  * Most NICs support RSS, which provides ordering and explicit affinity, and
  276  * use the hash m_flag bits to indicate what header fields were covered by
  277  * the hash.  M_HASHTYPE_OPAQUE can be set by non-RSS cards or configurations
  278  * that provide an opaque flow identifier, allowing for ordering and
  279  * distribution without explicit affinity.
  280  */
  281 /* Microsoft RSS standard hash types */
  282 #define M_HASHTYPE_NONE                 0
  283 #define M_HASHTYPE_RSS_IPV4             1       /* IPv4 2-tuple */
  284 #define M_HASHTYPE_RSS_TCP_IPV4         2       /* TCPv4 4-tuple */
  285 #define M_HASHTYPE_RSS_IPV6             3       /* IPv6 2-tuple */
  286 #define M_HASHTYPE_RSS_TCP_IPV6         4       /* TCPv6 4-tuple */
  287 #define M_HASHTYPE_RSS_IPV6_EX          5       /* IPv6 2-tuple + ext hdrs */
  288 #define M_HASHTYPE_RSS_TCP_IPV6_EX      6       /* TCPv6 4-tiple + ext hdrs */
  289 /* Non-standard RSS hash types */
  290 #define M_HASHTYPE_RSS_UDP_IPV4         7       /* IPv4 UDP 4-tuple */
  291 #define M_HASHTYPE_RSS_UDP_IPV4_EX      8       /* IPv4 UDP 4-tuple + ext hdrs */
  292 #define M_HASHTYPE_RSS_UDP_IPV6         9       /* IPv6 UDP 4-tuple */
  293 #define M_HASHTYPE_RSS_UDP_IPV6_EX      10      /* IPv6 UDP 4-tuple + ext hdrs */
  294 
  295 #define M_HASHTYPE_OPAQUE               255     /* ordering, not affinity */
  296 
  297 #define M_HASHTYPE_CLEAR(m)     ((m)->m_pkthdr.rsstype = 0)
  298 #define M_HASHTYPE_GET(m)       ((m)->m_pkthdr.rsstype)
  299 #define M_HASHTYPE_SET(m, v)    ((m)->m_pkthdr.rsstype = (v))
  300 #define M_HASHTYPE_TEST(m, v)   (M_HASHTYPE_GET(m) == (v))
  301 
  302 /*
  303  * COS/QOS class and quality of service tags.
  304  * It uses DSCP code points as base.
  305  */
  306 #define QOS_DSCP_CS0            0x00
  307 #define QOS_DSCP_DEF            QOS_DSCP_CS0
  308 #define QOS_DSCP_CS1            0x20
  309 #define QOS_DSCP_AF11           0x28
  310 #define QOS_DSCP_AF12           0x30
  311 #define QOS_DSCP_AF13           0x38
  312 #define QOS_DSCP_CS2            0x40
  313 #define QOS_DSCP_AF21           0x48
  314 #define QOS_DSCP_AF22           0x50
  315 #define QOS_DSCP_AF23           0x58
  316 #define QOS_DSCP_CS3            0x60
  317 #define QOS_DSCP_AF31           0x68
  318 #define QOS_DSCP_AF32           0x70
  319 #define QOS_DSCP_AF33           0x78
  320 #define QOS_DSCP_CS4            0x80
  321 #define QOS_DSCP_AF41           0x88
  322 #define QOS_DSCP_AF42           0x90
  323 #define QOS_DSCP_AF43           0x98
  324 #define QOS_DSCP_CS5            0xa0
  325 #define QOS_DSCP_EF             0xb8
  326 #define QOS_DSCP_CS6            0xc0
  327 #define QOS_DSCP_CS7            0xe0
  328 
  329 /*
  330  * External mbuf storage buffer types.
  331  */
  332 #define EXT_CLUSTER     1       /* mbuf cluster */
  333 #define EXT_SFBUF       2       /* sendfile(2)'s sf_bufs */
  334 #define EXT_JUMBOP      3       /* jumbo cluster 4096 bytes */
  335 #define EXT_JUMBO9      4       /* jumbo cluster 9216 bytes */
  336 #define EXT_JUMBO16     5       /* jumbo cluster 16184 bytes */
  337 #define EXT_PACKET      6       /* mbuf+cluster from packet zone */
  338 #define EXT_MBUF        7       /* external mbuf reference (M_IOVEC) */
  339 
  340 #define EXT_VENDOR1     224     /* for vendor-internal use */
  341 #define EXT_VENDOR2     225     /* for vendor-internal use */
  342 #define EXT_VENDOR3     226     /* for vendor-internal use */
  343 #define EXT_VENDOR4     227     /* for vendor-internal use */
  344 
  345 #define EXT_EXP1        244     /* for experimental use */
  346 #define EXT_EXP2        245     /* for experimental use */
  347 #define EXT_EXP3        246     /* for experimental use */
  348 #define EXT_EXP4        247     /* for experimental use */
  349 
  350 #define EXT_NET_DRV     252     /* custom ext_buf provided by net driver(s) */
  351 #define EXT_MOD_TYPE    253     /* custom module's ext_buf type */
  352 #define EXT_DISPOSABLE  254     /* can throw this buffer away w/page flipping */
  353 #define EXT_EXTREF      255     /* has externally maintained ext_cnt ptr */
  354 
  355 /*
  356  * Flags for external mbuf buffer types.
  357  * NB: limited to the lower 24 bits.
  358  */
  359 #define EXT_FLAG_EMBREF         0x000001        /* embedded ext_cnt, notyet */
  360 #define EXT_FLAG_EXTREF         0x000002        /* external ext_cnt, notyet */
  361 #define EXT_FLAG_NOFREE         0x000010        /* don't free mbuf to pool, notyet */
  362 
  363 #define EXT_FLAG_VENDOR1        0x010000        /* for vendor-internal use */
  364 #define EXT_FLAG_VENDOR2        0x020000        /* for vendor-internal use */
  365 #define EXT_FLAG_VENDOR3        0x040000        /* for vendor-internal use */
  366 #define EXT_FLAG_VENDOR4        0x080000        /* for vendor-internal use */
  367 
  368 #define EXT_FLAG_EXP1           0x100000        /* for experimental use */
  369 #define EXT_FLAG_EXP2           0x200000        /* for experimental use */
  370 #define EXT_FLAG_EXP3           0x400000        /* for experimental use */
  371 #define EXT_FLAG_EXP4           0x800000        /* for experimental use */
  372 
  373 /*
  374  * EXT flag description for use with printf(9) %b identifier.
  375  */
  376 #define EXT_FLAG_BITS \
  377     "\2\1EXT_FLAG_EMBREF\2EXT_FLAG_EXTREF\5EXT_FLAG_NOFREE" \
  378     "\21EXT_FLAG_VENDOR1\22EXT_FLAG_VENDOR2\23EXT_FLAG_VENDOR3" \
  379     "\24EXT_FLAG_VENDOR4\25EXT_FLAG_EXP1\26EXT_FLAG_EXP2\27EXT_FLAG_EXP3" \
  380     "\30EXT_FLAG_EXP4"
  381 
  382 /*
  383  * External reference/free functions.
  384  */
  385 void sf_ext_ref(void *, void *);
  386 void sf_ext_free(void *, void *);
  387 
  388 /*
  389  * Flags indicating checksum, segmentation and other offload work to be
  390  * done, or already done, by hardware or lower layers.  It is split into
  391  * separate inbound and outbound flags.
  392  *
  393  * Outbound flags that are set by upper protocol layers requesting lower
  394  * layers, or ideally the hardware, to perform these offloading tasks.
  395  * For outbound packets this field and its flags can be directly tested
  396  * against ifnet if_hwassist.
  397  */
  398 #define CSUM_IP                 0x00000001      /* IP header checksum offload */
  399 #define CSUM_IP_UDP             0x00000002      /* UDP checksum offload */
  400 #define CSUM_IP_TCP             0x00000004      /* TCP checksum offload */
  401 #define CSUM_IP_SCTP            0x00000008      /* SCTP checksum offload */
  402 #define CSUM_IP_TSO             0x00000010      /* TCP segmentation offload */
  403 #define CSUM_IP_ISCSI           0x00000020      /* iSCSI checksum offload */
  404 
  405 #define CSUM_IP6_UDP            0x00000200      /* UDP checksum offload */
  406 #define CSUM_IP6_TCP            0x00000400      /* TCP checksum offload */
  407 #define CSUM_IP6_SCTP           0x00000800      /* SCTP checksum offload */
  408 #define CSUM_IP6_TSO            0x00001000      /* TCP segmentation offload */
  409 #define CSUM_IP6_ISCSI          0x00002000      /* iSCSI checksum offload */
  410 
  411 /* Inbound checksum support where the checksum was verified by hardware. */
  412 #define CSUM_L3_CALC            0x01000000      /* calculated layer 3 csum */
  413 #define CSUM_L3_VALID           0x02000000      /* checksum is correct */
  414 #define CSUM_L4_CALC            0x04000000      /* calculated layer 4 csum */
  415 #define CSUM_L4_VALID           0x08000000      /* checksum is correct */
  416 #define CSUM_L5_CALC            0x10000000      /* calculated layer 5 csum */
  417 #define CSUM_L5_VALID           0x20000000      /* checksum is correct */
  418 #define CSUM_COALESED           0x40000000      /* contains merged segments */
  419 
  420 /*
  421  * CSUM flag description for use with printf(9) %b identifier.
  422  */
  423 #define CSUM_BITS \
  424     "\2\1CSUM_IP\2CSUM_IP_UDP\3CSUM_IP_TCP\4CSUM_IP_SCTP\5CSUM_IP_TSO" \
  425     "\6CSUM_IP_ISCSI" \
  426     "\12CSUM_IP6_UDP\13CSUM_IP6_TCP\14CSUM_IP6_SCTP\15CSUM_IP6_TSO" \
  427     "\16CSUM_IP6_ISCSI" \
  428     "\31CSUM_L3_CALC\32CSUM_L3_VALID\33CSUM_L4_CALC\34CSUM_L4_VALID" \
  429     "\35CSUM_L5_CALC\36CSUM_L5_VALID\37CSUM_COALESED"
  430 
  431 /* CSUM flags compatibility mappings. */
  432 #define CSUM_IP_CHECKED         CSUM_L3_CALC
  433 #define CSUM_IP_VALID           CSUM_L3_VALID
  434 #define CSUM_DATA_VALID         CSUM_L4_VALID
  435 #define CSUM_PSEUDO_HDR         CSUM_L4_CALC
  436 #define CSUM_SCTP_VALID         CSUM_L4_VALID
  437 #define CSUM_DELAY_DATA         (CSUM_TCP|CSUM_UDP)
  438 #define CSUM_DELAY_IP           CSUM_IP         /* Only v4, no v6 IP hdr csum */
  439 #define CSUM_DELAY_DATA_IPV6    (CSUM_TCP_IPV6|CSUM_UDP_IPV6)
  440 #define CSUM_DATA_VALID_IPV6    CSUM_DATA_VALID
  441 #define CSUM_TCP                CSUM_IP_TCP
  442 #define CSUM_UDP                CSUM_IP_UDP
  443 #define CSUM_SCTP               CSUM_IP_SCTP
  444 #define CSUM_TSO                (CSUM_IP_TSO|CSUM_IP6_TSO)
  445 #define CSUM_UDP_IPV6           CSUM_IP6_UDP
  446 #define CSUM_TCP_IPV6           CSUM_IP6_TCP
  447 #define CSUM_SCTP_IPV6          CSUM_IP6_SCTP
  448 
  449 /*
  450  * mbuf types describing the content of the mbuf (including external storage).
  451  */
  452 #define MT_NOTMBUF      0       /* USED INTERNALLY ONLY! Object is not mbuf */
  453 #define MT_DATA         1       /* dynamic (data) allocation */
  454 #define MT_HEADER       MT_DATA /* packet header, use M_PKTHDR instead */
  455 
  456 #define MT_VENDOR1      4       /* for vendor-internal use */
  457 #define MT_VENDOR2      5       /* for vendor-internal use */
  458 #define MT_VENDOR3      6       /* for vendor-internal use */
  459 #define MT_VENDOR4      7       /* for vendor-internal use */
  460 
  461 #define MT_SONAME       8       /* socket name */
  462 
  463 #define MT_EXP1         9       /* for experimental use */
  464 #define MT_EXP2         10      /* for experimental use */
  465 #define MT_EXP3         11      /* for experimental use */
  466 #define MT_EXP4         12      /* for experimental use */
  467 
  468 #define MT_CONTROL      14      /* extra-data protocol message */
  469 #define MT_OOBDATA      15      /* expedited data  */
  470 #define MT_NTYPES       16      /* number of mbuf types for mbtypes[] */
  471 
  472 #define MT_NOINIT       255     /* Not a type but a flag to allocate
  473                                    a non-initialized mbuf */
  474 
  475 /*
  476  * String names of mbuf-related UMA(9) and malloc(9) types.  Exposed to
  477  * !_KERNEL so that monitoring tools can look up the zones with
  478  * libmemstat(3).
  479  */
  480 #define MBUF_MEM_NAME           "mbuf"
  481 #define MBUF_CLUSTER_MEM_NAME   "mbuf_cluster"
  482 #define MBUF_PACKET_MEM_NAME    "mbuf_packet"
  483 #define MBUF_JUMBOP_MEM_NAME    "mbuf_jumbo_page"
  484 #define MBUF_JUMBO9_MEM_NAME    "mbuf_jumbo_9k"
  485 #define MBUF_JUMBO16_MEM_NAME   "mbuf_jumbo_16k"
  486 #define MBUF_TAG_MEM_NAME       "mbuf_tag"
  487 #define MBUF_EXTREFCNT_MEM_NAME "mbuf_ext_refcnt"
  488 
  489 #ifdef _KERNEL
  490 
  491 #ifdef WITNESS
  492 #define MBUF_CHECKSLEEP(how) do {                                       \
  493         if (how == M_WAITOK)                                            \
  494                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,         \
  495                     "Sleeping in \"%s\"", __func__);                    \
  496 } while (0)
  497 #else
  498 #define MBUF_CHECKSLEEP(how)
  499 #endif
  500 
  501 /*
  502  * Network buffer allocation API
  503  *
  504  * The rest of it is defined in kern/kern_mbuf.c
  505  */
  506 extern uma_zone_t       zone_mbuf;
  507 extern uma_zone_t       zone_clust;
  508 extern uma_zone_t       zone_pack;
  509 extern uma_zone_t       zone_jumbop;
  510 extern uma_zone_t       zone_jumbo9;
  511 extern uma_zone_t       zone_jumbo16;
  512 extern uma_zone_t       zone_ext_refcnt;
  513 
  514 void             mb_free_ext(struct mbuf *);
  515 int              m_pkthdr_init(struct mbuf *, int);
  516 
  517 static __inline int
  518 m_gettype(int size)
  519 {
  520         int type;
  521 
  522         switch (size) {
  523         case MSIZE:
  524                 type = EXT_MBUF;
  525                 break;
  526         case MCLBYTES:
  527                 type = EXT_CLUSTER;
  528                 break;
  529 #if MJUMPAGESIZE != MCLBYTES
  530         case MJUMPAGESIZE:
  531                 type = EXT_JUMBOP;
  532                 break;
  533 #endif
  534         case MJUM9BYTES:
  535                 type = EXT_JUMBO9;
  536                 break;
  537         case MJUM16BYTES:
  538                 type = EXT_JUMBO16;
  539                 break;
  540         default:
  541                 panic("%s: invalid cluster size %d", __func__, size);
  542         }
  543 
  544         return (type);
  545 }
  546 
  547 /*
  548  * Associated an external reference counted buffer with an mbuf.
  549  */
  550 static __inline void
  551 m_extaddref(struct mbuf *m, caddr_t buf, u_int size, u_int *ref_cnt,
  552     void (*freef)(struct mbuf *, void *, void *), void *arg1, void *arg2)
  553 {
  554 
  555         KASSERT(ref_cnt != NULL, ("%s: ref_cnt not provided", __func__));
  556 
  557         atomic_add_int(ref_cnt, 1);
  558         m->m_flags |= M_EXT;
  559         m->m_ext.ext_buf = buf;
  560         m->m_ext.ext_cnt = ref_cnt;
  561         m->m_data = m->m_ext.ext_buf;
  562         m->m_ext.ext_size = size;
  563         m->m_ext.ext_free = freef;
  564         m->m_ext.ext_arg1 = arg1;
  565         m->m_ext.ext_arg2 = arg2;
  566         m->m_ext.ext_type = EXT_EXTREF;
  567 }
  568 
  569 static __inline uma_zone_t
  570 m_getzone(int size)
  571 {
  572         uma_zone_t zone;
  573 
  574         switch (size) {
  575         case MCLBYTES:
  576                 zone = zone_clust;
  577                 break;
  578 #if MJUMPAGESIZE != MCLBYTES
  579         case MJUMPAGESIZE:
  580                 zone = zone_jumbop;
  581                 break;
  582 #endif
  583         case MJUM9BYTES:
  584                 zone = zone_jumbo9;
  585                 break;
  586         case MJUM16BYTES:
  587                 zone = zone_jumbo16;
  588                 break;
  589         default:
  590                 panic("%s: invalid cluster size %d", __func__, size);
  591         }
  592 
  593         return (zone);
  594 }
  595 
  596 /*
  597  * Initialize an mbuf with linear storage.
  598  *
  599  * Inline because the consumer text overhead will be roughly the same to
  600  * initialize or call a function with this many parameters and M_PKTHDR
  601  * should go away with constant propagation for !MGETHDR.
  602  */
  603 static __inline int
  604 m_init(struct mbuf *m, uma_zone_t zone, int size, int how, short type,
  605     int flags)
  606 {
  607         int error;
  608 
  609         m->m_next = NULL;
  610         m->m_nextpkt = NULL;
  611         m->m_data = m->m_dat;
  612         m->m_len = 0;
  613         m->m_flags = flags;
  614         m->m_type = type;
  615         if (flags & M_PKTHDR) {
  616                 if ((error = m_pkthdr_init(m, how)) != 0)
  617                         return (error);
  618         }
  619 
  620         return (0);
  621 }
  622 
  623 static __inline struct mbuf *
  624 m_get(int how, short type)
  625 {
  626         struct mb_args args;
  627 
  628         args.flags = 0;
  629         args.type = type;
  630         return (uma_zalloc_arg(zone_mbuf, &args, how));
  631 }
  632 
  633 /*
  634  * XXX This should be deprecated, very little use.
  635  */
  636 static __inline struct mbuf *
  637 m_getclr(int how, short type)
  638 {
  639         struct mbuf *m;
  640         struct mb_args args;
  641 
  642         args.flags = 0;
  643         args.type = type;
  644         m = uma_zalloc_arg(zone_mbuf, &args, how);
  645         if (m != NULL)
  646                 bzero(m->m_data, MLEN);
  647         return (m);
  648 }
  649 
  650 static __inline struct mbuf *
  651 m_gethdr(int how, short type)
  652 {
  653         struct mb_args args;
  654 
  655         args.flags = M_PKTHDR;
  656         args.type = type;
  657         return (uma_zalloc_arg(zone_mbuf, &args, how));
  658 }
  659 
  660 static __inline struct mbuf *
  661 m_getcl(int how, short type, int flags)
  662 {
  663         struct mb_args args;
  664 
  665         args.flags = flags;
  666         args.type = type;
  667         return (uma_zalloc_arg(zone_pack, &args, how));
  668 }
  669 
  670 static __inline void
  671 m_clget(struct mbuf *m, int how)
  672 {
  673 
  674         if (m->m_flags & M_EXT)
  675                 printf("%s: %p mbuf already has external storage\n", __func__, m);
  676         m->m_ext.ext_buf = (char *)NULL;
  677         uma_zalloc_arg(zone_clust, m, how);
  678         /*
  679          * On a cluster allocation failure, drain the packet zone and retry,
  680          * we might be able to loosen a few clusters up on the drain.
  681          */
  682         if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) {
  683                 zone_drain(zone_pack);
  684                 uma_zalloc_arg(zone_clust, m, how);
  685         }
  686 }
  687 
  688 /*
  689  * m_cljget() is different from m_clget() as it can allocate clusters without
  690  * attaching them to an mbuf.  In that case the return value is the pointer
  691  * to the cluster of the requested size.  If an mbuf was specified, it gets
  692  * the cluster attached to it and the return value can be safely ignored.
  693  * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
  694  */
  695 static __inline void *
  696 m_cljget(struct mbuf *m, int how, int size)
  697 {
  698         uma_zone_t zone;
  699 
  700         if (m && m->m_flags & M_EXT)
  701                 printf("%s: %p mbuf already has external storage\n", __func__, m);
  702         if (m != NULL)
  703                 m->m_ext.ext_buf = NULL;
  704 
  705         zone = m_getzone(size);
  706         return (uma_zalloc_arg(zone, m, how));
  707 }
  708 
  709 static __inline void
  710 m_cljset(struct mbuf *m, void *cl, int type)
  711 {
  712         uma_zone_t zone;
  713         int size;
  714 
  715         switch (type) {
  716         case EXT_CLUSTER:
  717                 size = MCLBYTES;
  718                 zone = zone_clust;
  719                 break;
  720 #if MJUMPAGESIZE != MCLBYTES
  721         case EXT_JUMBOP:
  722                 size = MJUMPAGESIZE;
  723                 zone = zone_jumbop;
  724                 break;
  725 #endif
  726         case EXT_JUMBO9:
  727                 size = MJUM9BYTES;
  728                 zone = zone_jumbo9;
  729                 break;
  730         case EXT_JUMBO16:
  731                 size = MJUM16BYTES;
  732                 zone = zone_jumbo16;
  733                 break;
  734         default:
  735                 panic("%s: unknown cluster type %d", __func__, type);
  736                 break;
  737         }
  738 
  739         m->m_data = m->m_ext.ext_buf = cl;
  740         m->m_ext.ext_free = m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
  741         m->m_ext.ext_size = size;
  742         m->m_ext.ext_type = type;
  743         m->m_ext.ext_flags = 0;
  744         m->m_ext.ext_cnt = uma_find_refcnt(zone, cl);
  745         m->m_flags |= M_EXT;
  746 
  747 }
  748 
  749 static __inline void
  750 m_chtype(struct mbuf *m, short new_type)
  751 {
  752 
  753         m->m_type = new_type;
  754 }
  755 
  756 static __inline void
  757 m_clrprotoflags(struct mbuf *m)
  758 {
  759 
  760         m->m_flags &= ~M_PROTOFLAGS;
  761 }
  762 
  763 static __inline struct mbuf *
  764 m_last(struct mbuf *m)
  765 {
  766 
  767         while (m->m_next)
  768                 m = m->m_next;
  769         return (m);
  770 }
  771 
  772 /*
  773  * mbuf, cluster, and external object allocation macros (for compatibility
  774  * purposes).
  775  */
  776 #define M_MOVE_PKTHDR(to, from) m_move_pkthdr((to), (from))
  777 #define MGET(m, how, type)      ((m) = m_get((how), (type)))
  778 #define MGETHDR(m, how, type)   ((m) = m_gethdr((how), (type)))
  779 #define MCLGET(m, how)          m_clget((m), (how))
  780 #define MEXTADD(m, buf, size, free, arg1, arg2, flags, type)            \
  781     (void )m_extadd((m), (caddr_t)(buf), (size), (free), (arg1), (arg2),\
  782     (flags), (type), M_NOWAIT)
  783 #define m_getm(m, len, how, type)                                       \
  784     m_getm2((m), (len), (how), (type), M_PKTHDR)
  785 
  786 /*
  787  * Evaluate TRUE if it's safe to write to the mbuf m's data region (this can
  788  * be both the local data payload, or an external buffer area, depending on
  789  * whether M_EXT is set).
  790  */
  791 #define M_WRITABLE(m)   (!((m)->m_flags & M_RDONLY) &&                  \
  792                          (!(((m)->m_flags & M_EXT)) ||                  \
  793                          (*((m)->m_ext.ext_cnt) == 1)) )                \
  794 
  795 /* Check if the supplied mbuf has a packet header, or else panic. */
  796 #define M_ASSERTPKTHDR(m)                                               \
  797         KASSERT((m) != NULL && (m)->m_flags & M_PKTHDR,                 \
  798             ("%s: no mbuf packet header!", __func__))
  799 
  800 /*
  801  * Ensure that the supplied mbuf is a valid, non-free mbuf.
  802  *
  803  * XXX: Broken at the moment.  Need some UMA magic to make it work again.
  804  */
  805 #define M_ASSERTVALID(m)                                                \
  806         KASSERT((((struct mbuf *)m)->m_flags & 0) == 0,                 \
  807             ("%s: attempted use of a free mbuf!", __func__))
  808 
  809 /*
  810  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place an
  811  * object of the specified size at the end of the mbuf, longword aligned.
  812  */
  813 #define M_ALIGN(m, len) do {                                            \
  814         KASSERT(!((m)->m_flags & (M_PKTHDR|M_EXT)),                     \
  815                 ("%s: M_ALIGN not normal mbuf", __func__));             \
  816         KASSERT((m)->m_data == (m)->m_dat,                              \
  817                 ("%s: M_ALIGN not a virgin mbuf", __func__));           \
  818         (m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1);            \
  819 } while (0)
  820 
  821 /*
  822  * As above, for mbufs allocated with m_gethdr/MGETHDR or initialized by
  823  * M_DUP/MOVE_PKTHDR.
  824  */
  825 #define MH_ALIGN(m, len) do {                                           \
  826         KASSERT((m)->m_flags & M_PKTHDR && !((m)->m_flags & M_EXT),     \
  827                 ("%s: MH_ALIGN not PKTHDR mbuf", __func__));            \
  828         KASSERT((m)->m_data == (m)->m_pktdat,                           \
  829                 ("%s: MH_ALIGN not a virgin mbuf", __func__));          \
  830         (m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1);           \
  831 } while (0)
  832 
  833 /*
  834  * As above, for mbuf with external storage.
  835  */
  836 #define MEXT_ALIGN(m, len) do {                                         \
  837         KASSERT((m)->m_flags & M_EXT,                                   \
  838                 ("%s: MEXT_ALIGN not an M_EXT mbuf", __func__));        \
  839         KASSERT((m)->m_data == (m)->m_ext.ext_buf,                      \
  840                 ("%s: MEXT_ALIGN not a virgin mbuf", __func__));        \
  841         (m)->m_data += ((m)->m_ext.ext_size - (len)) &                  \
  842             ~(sizeof(long) - 1);                                        \
  843 } while (0)
  844 
  845 /*
  846  * Return the address of the start of the buffer associated with an mbuf,
  847  * handling external storage, packet-header mbufs, and regular data mbufs.
  848  */
  849 #define M_START(m)                                                      \
  850         (((m)->m_flags & M_EXT) ? (m)->m_ext.ext_buf :                  \
  851          ((m)->m_flags & M_PKTHDR) ? &(m)->m_pktdat[0] :                \
  852          &(m)->m_dat[0])
  853 
  854 /*
  855  * Return the size of the buffer associated with an mbuf, handling external
  856  * storage, packet-header mbufs, and regular data mbufs.
  857  */
  858 #define M_SIZE(m)                                                       \
  859         (((m)->m_flags & M_EXT) ? (m)->m_ext.ext_size :                 \
  860          ((m)->m_flags & M_PKTHDR) ? MHLEN :                            \
  861          MLEN)
  862 
  863 /*
  864  * Compute the amount of space available before the current start of data in
  865  * an mbuf.
  866  *
  867  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
  868  * of checking writability of the mbuf data area rests solely with the caller.
  869  *
  870  * NB: In previous versions, M_LEADINGSPACE() would only check M_WRITABLE()
  871  * for mbufs with external storage.  We now allow mbuf-embedded data to be
  872  * read-only as well.
  873  */
  874 #define M_LEADINGSPACE(m)                                               \
  875         (M_WRITABLE(m) ? ((m)->m_data - M_START(m)) : 0)
  876 
  877 /*
  878  * Compute the amount of space available after the end of data in an mbuf.
  879  *
  880  * The M_WRITABLE() is a temporary, conservative safety measure: the burden
  881  * of checking writability of the mbuf data area rests solely with the caller.
  882  *
  883  * NB: In previous versions, M_TRAILINGSPACE() would only check M_WRITABLE()
  884  * for mbufs with external storage.  We now allow mbuf-embedded data to be
  885  * read-only as well.
  886  */
  887 #define M_TRAILINGSPACE(m)                                              \
  888         (M_WRITABLE(m) ?                                                \
  889             ((M_START(m) + M_SIZE(m)) - ((m)->m_data + (m)->m_len)) : 0)
  890 
  891 /*
  892  * Arrange to prepend space of size plen to mbuf m.  If a new mbuf must be
  893  * allocated, how specifies whether to wait.  If the allocation fails, the
  894  * original mbuf chain is freed and m is set to NULL.
  895  */
  896 #define M_PREPEND(m, plen, how) do {                                    \
  897         struct mbuf **_mmp = &(m);                                      \
  898         struct mbuf *_mm = *_mmp;                                       \
  899         int _mplen = (plen);                                            \
  900         int __mhow = (how);                                             \
  901                                                                         \
  902         MBUF_CHECKSLEEP(how);                                           \
  903         if (M_LEADINGSPACE(_mm) >= _mplen) {                            \
  904                 _mm->m_data -= _mplen;                                  \
  905                 _mm->m_len += _mplen;                                   \
  906         } else                                                          \
  907                 _mm = m_prepend(_mm, _mplen, __mhow);                   \
  908         if (_mm != NULL && _mm->m_flags & M_PKTHDR)                     \
  909                 _mm->m_pkthdr.len += _mplen;                            \
  910         *_mmp = _mm;                                                    \
  911 } while (0)
  912 
  913 /*
  914  * Change mbuf to new type.  This is a relatively expensive operation and
  915  * should be avoided.
  916  */
  917 #define MCHTYPE(m, t)   m_chtype((m), (t))
  918 
  919 /* Length to m_copy to copy all. */
  920 #define M_COPYALL       1000000000
  921 
  922 /* Compatibility with 4.3. */
  923 #define m_copy(m, o, l) m_copym((m), (o), (l), M_NOWAIT)
  924 
  925 extern int              max_datalen;    /* MHLEN - max_hdr */
  926 extern int              max_hdr;        /* Largest link + protocol header */
  927 extern int              max_linkhdr;    /* Largest link-level header */
  928 extern int              max_protohdr;   /* Largest protocol header */
  929 extern int              nmbclusters;    /* Maximum number of clusters */
  930 
  931 struct uio;
  932 
  933 void             m_adj(struct mbuf *, int);
  934 void             m_align(struct mbuf *, int);
  935 int              m_apply(struct mbuf *, int, int,
  936                     int (*)(void *, void *, u_int), void *);
  937 int              m_append(struct mbuf *, int, c_caddr_t);
  938 void             m_cat(struct mbuf *, struct mbuf *);
  939 void             m_catpkt(struct mbuf *, struct mbuf *);
  940 int              m_extadd(struct mbuf *, caddr_t, u_int,
  941                     void (*)(struct mbuf *, void *, void *), void *, void *,
  942                     int, int, int);
  943 struct mbuf     *m_collapse(struct mbuf *, int, int);
  944 void             m_copyback(struct mbuf *, int, int, c_caddr_t);
  945 void             m_copydata(const struct mbuf *, int, int, caddr_t);
  946 struct mbuf     *m_copym(struct mbuf *, int, int, int);
  947 struct mbuf     *m_copymdata(struct mbuf *, struct mbuf *,
  948                     int, int, int, int);
  949 struct mbuf     *m_copypacket(struct mbuf *, int);
  950 void             m_copy_pkthdr(struct mbuf *, struct mbuf *);
  951 struct mbuf     *m_copyup(struct mbuf *, int, int);
  952 struct mbuf     *m_defrag(struct mbuf *, int);
  953 void             m_demote(struct mbuf *, int, int);
  954 struct mbuf     *m_devget(char *, int, int, struct ifnet *,
  955                     void (*)(char *, caddr_t, u_int));
  956 struct mbuf     *m_dup(struct mbuf *, int);
  957 int              m_dup_pkthdr(struct mbuf *, struct mbuf *, int);
  958 u_int            m_fixhdr(struct mbuf *);
  959 struct mbuf     *m_fragment(struct mbuf *, int, int);
  960 void             m_freem(struct mbuf *);
  961 struct mbuf     *m_get2(int, int, short, int);
  962 struct mbuf     *m_getjcl(int, short, int, int);
  963 struct mbuf     *m_getm2(struct mbuf *, int, int, short, int);
  964 struct mbuf     *m_getptr(struct mbuf *, int, int *);
  965 u_int            m_length(struct mbuf *, struct mbuf **);
  966 int              m_mbuftouio(struct uio *, struct mbuf *, int);
  967 void             m_move_pkthdr(struct mbuf *, struct mbuf *);
  968 struct mbuf     *m_prepend(struct mbuf *, int, int);
  969 void             m_print(const struct mbuf *, int);
  970 struct mbuf     *m_pulldown(struct mbuf *, int, int, int *);
  971 struct mbuf     *m_pullup(struct mbuf *, int);
  972 int              m_sanity(struct mbuf *, int);
  973 struct mbuf     *m_split(struct mbuf *, int, int);
  974 struct mbuf     *m_uiotombuf(struct uio *, int, int, int, int);
  975 struct mbuf     *m_unshare(struct mbuf *, int);
  976 
  977 /*-
  978  * Network packets may have annotations attached by affixing a list of
  979  * "packet tags" to the pkthdr structure.  Packet tags are dynamically
  980  * allocated semi-opaque data structures that have a fixed header
  981  * (struct m_tag) that specifies the size of the memory block and a
  982  * <cookie,type> pair that identifies it.  The cookie is a 32-bit unique
  983  * unsigned value used to identify a module or ABI.  By convention this value
  984  * is chosen as the date+time that the module is created, expressed as the
  985  * number of seconds since the epoch (e.g., using date -u +'%s').  The type
  986  * value is an ABI/module-specific value that identifies a particular
  987  * annotation and is private to the module.  For compatibility with systems
  988  * like OpenBSD that define packet tags w/o an ABI/module cookie, the value
  989  * PACKET_ABI_COMPAT is used to implement m_tag_get and m_tag_find
  990  * compatibility shim functions and several tag types are defined below.
  991  * Users that do not require compatibility should use a private cookie value
  992  * so that packet tag-related definitions can be maintained privately.
  993  *
  994  * Note that the packet tag returned by m_tag_alloc has the default memory
  995  * alignment implemented by malloc.  To reference private data one can use a
  996  * construct like:
  997  *
  998  *      struct m_tag *mtag = m_tag_alloc(...);
  999  *      struct foo *p = (struct foo *)(mtag+1);
 1000  *
 1001  * if the alignment of struct m_tag is sufficient for referencing members of
 1002  * struct foo.  Otherwise it is necessary to embed struct m_tag within the
 1003  * private data structure to insure proper alignment; e.g.,
 1004  *
 1005  *      struct foo {
 1006  *              struct m_tag    tag;
 1007  *              ...
 1008  *      };
 1009  *      struct foo *p = (struct foo *) m_tag_alloc(...);
 1010  *      struct m_tag *mtag = &p->tag;
 1011  */
 1012 
 1013 /*
 1014  * Persistent tags stay with an mbuf until the mbuf is reclaimed.  Otherwise
 1015  * tags are expected to ``vanish'' when they pass through a network
 1016  * interface.  For most interfaces this happens normally as the tags are
 1017  * reclaimed when the mbuf is free'd.  However in some special cases
 1018  * reclaiming must be done manually.  An example is packets that pass through
 1019  * the loopback interface.  Also, one must be careful to do this when
 1020  * ``turning around'' packets (e.g., icmp_reflect).
 1021  *
 1022  * To mark a tag persistent bit-or this flag in when defining the tag id.
 1023  * The tag will then be treated as described above.
 1024  */
 1025 #define MTAG_PERSISTENT                         0x800
 1026 
 1027 #define PACKET_TAG_NONE                         0  /* Nadda */
 1028 
 1029 /* Packet tags for use with PACKET_ABI_COMPAT. */
 1030 #define PACKET_TAG_IPSEC_IN_DONE                1  /* IPsec applied, in */
 1031 #define PACKET_TAG_IPSEC_OUT_DONE               2  /* IPsec applied, out */
 1032 #define PACKET_TAG_IPSEC_IN_CRYPTO_DONE         3  /* NIC IPsec crypto done */
 1033 #define PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED      4  /* NIC IPsec crypto req'ed */
 1034 #define PACKET_TAG_IPSEC_IN_COULD_DO_CRYPTO     5  /* NIC notifies IPsec */
 1035 #define PACKET_TAG_IPSEC_PENDING_TDB            6  /* Reminder to do IPsec */
 1036 #define PACKET_TAG_BRIDGE                       7  /* Bridge processing done */
 1037 #define PACKET_TAG_GIF                          8  /* GIF processing done */
 1038 #define PACKET_TAG_GRE                          9  /* GRE processing done */
 1039 #define PACKET_TAG_IN_PACKET_CHECKSUM           10 /* NIC checksumming done */
 1040 #define PACKET_TAG_ENCAP                        11 /* Encap.  processing */
 1041 #define PACKET_TAG_IPSEC_SOCKET                 12 /* IPSEC socket ref */
 1042 #define PACKET_TAG_IPSEC_HISTORY                13 /* IPSEC history */
 1043 #define PACKET_TAG_IPV6_INPUT                   14 /* IPV6 input processing */
 1044 #define PACKET_TAG_DUMMYNET                     15 /* dummynet info */
 1045 #define PACKET_TAG_DIVERT                       17 /* divert info */
 1046 #define PACKET_TAG_IPFORWARD                    18 /* ipforward info */
 1047 #define PACKET_TAG_MACLABEL     (19 | MTAG_PERSISTENT) /* MAC label */
 1048 #define PACKET_TAG_PF           (21 | MTAG_PERSISTENT) /* PF/ALTQ information */
 1049 #define PACKET_TAG_RTSOCKFAM                    25 /* rtsock sa family */
 1050 #define PACKET_TAG_IPOPTIONS                    27 /* Saved IP options */
 1051 #define PACKET_TAG_CARP                         28 /* CARP info */
 1052 #define PACKET_TAG_IPSEC_NAT_T_PORTS            29 /* two uint16_t */
 1053 #define PACKET_TAG_ND_OUTGOING                  30 /* ND outgoing */
 1054 
 1055 /* Specific cookies and tags. */
 1056 
 1057 /* Packet tag routines. */
 1058 struct m_tag    *m_tag_alloc(u_int32_t, int, int, int);
 1059 void             m_tag_delete(struct mbuf *, struct m_tag *);
 1060 void             m_tag_delete_chain(struct mbuf *, struct m_tag *);
 1061 void             m_tag_free_default(struct m_tag *);
 1062 struct m_tag    *m_tag_locate(struct mbuf *, u_int32_t, int, struct m_tag *);
 1063 struct m_tag    *m_tag_copy(struct m_tag *, int);
 1064 int              m_tag_copy_chain(struct mbuf *, struct mbuf *, int);
 1065 void             m_tag_delete_nonpersistent(struct mbuf *);
 1066 
 1067 /*
 1068  * Initialize the list of tags associated with an mbuf.
 1069  */
 1070 static __inline void
 1071 m_tag_init(struct mbuf *m)
 1072 {
 1073 
 1074         SLIST_INIT(&m->m_pkthdr.tags);
 1075 }
 1076 
 1077 /*
 1078  * Set up the contents of a tag.  Note that this does not fill in the free
 1079  * method; the caller is expected to do that.
 1080  *
 1081  * XXX probably should be called m_tag_init, but that was already taken.
 1082  */
 1083 static __inline void
 1084 m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
 1085 {
 1086 
 1087         t->m_tag_id = type;
 1088         t->m_tag_len = len;
 1089         t->m_tag_cookie = cookie;
 1090 }
 1091 
 1092 /*
 1093  * Reclaim resources associated with a tag.
 1094  */
 1095 static __inline void
 1096 m_tag_free(struct m_tag *t)
 1097 {
 1098 
 1099         (*t->m_tag_free)(t);
 1100 }
 1101 
 1102 /*
 1103  * Return the first tag associated with an mbuf.
 1104  */
 1105 static __inline struct m_tag *
 1106 m_tag_first(struct mbuf *m)
 1107 {
 1108 
 1109         return (SLIST_FIRST(&m->m_pkthdr.tags));
 1110 }
 1111 
 1112 /*
 1113  * Return the next tag in the list of tags associated with an mbuf.
 1114  */
 1115 static __inline struct m_tag *
 1116 m_tag_next(struct mbuf *m, struct m_tag *t)
 1117 {
 1118 
 1119         return (SLIST_NEXT(t, m_tag_link));
 1120 }
 1121 
 1122 /*
 1123  * Prepend a tag to the list of tags associated with an mbuf.
 1124  */
 1125 static __inline void
 1126 m_tag_prepend(struct mbuf *m, struct m_tag *t)
 1127 {
 1128 
 1129         SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
 1130 }
 1131 
 1132 /*
 1133  * Unlink a tag from the list of tags associated with an mbuf.
 1134  */
 1135 static __inline void
 1136 m_tag_unlink(struct mbuf *m, struct m_tag *t)
 1137 {
 1138 
 1139         SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
 1140 }
 1141 
 1142 /* These are for OpenBSD compatibility. */
 1143 #define MTAG_ABI_COMPAT         0               /* compatibility ABI */
 1144 
 1145 static __inline struct m_tag *
 1146 m_tag_get(int type, int length, int wait)
 1147 {
 1148         return (m_tag_alloc(MTAG_ABI_COMPAT, type, length, wait));
 1149 }
 1150 
 1151 static __inline struct m_tag *
 1152 m_tag_find(struct mbuf *m, int type, struct m_tag *start)
 1153 {
 1154         return (SLIST_EMPTY(&m->m_pkthdr.tags) ? (struct m_tag *)NULL :
 1155             m_tag_locate(m, MTAG_ABI_COMPAT, type, start));
 1156 }
 1157 
 1158 static __inline struct mbuf *
 1159 m_free(struct mbuf *m)
 1160 {
 1161         struct mbuf *n = m->m_next;
 1162 
 1163         if ((m->m_flags & (M_PKTHDR|M_NOFREE)) == (M_PKTHDR|M_NOFREE))
 1164                 m_tag_delete_chain(m, NULL);
 1165         if (m->m_flags & M_EXT)
 1166                 mb_free_ext(m);
 1167         else if ((m->m_flags & M_NOFREE) == 0)
 1168                 uma_zfree(zone_mbuf, m);
 1169         return (n);
 1170 }
 1171 
 1172 static int inline
 1173 rt_m_getfib(struct mbuf *m)
 1174 {
 1175         KASSERT(m->m_flags & M_PKTHDR , ("Attempt to get FIB from non header mbuf."));
 1176         return (m->m_pkthdr.fibnum);
 1177 }
 1178 
 1179 #define M_GETFIB(_m)   rt_m_getfib(_m)
 1180 
 1181 #define M_SETFIB(_m, _fib) do {                                         \
 1182         KASSERT((_m)->m_flags & M_PKTHDR, ("Attempt to set FIB on non header mbuf."));  \
 1183         ((_m)->m_pkthdr.fibnum) = (_fib);                               \
 1184 } while (0)
 1185 
 1186 #endif /* _KERNEL */
 1187 
 1188 #ifdef MBUF_PROFILING
 1189  void m_profile(struct mbuf *m);
 1190  #define M_PROFILE(m) m_profile(m)
 1191 #else
 1192  #define M_PROFILE(m)
 1193 #endif
 1194 
 1195 
 1196 #endif /* !_SYS_MBUF_H_ */

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