̾??

natm —

?ͥ??ƥ??֥⡼?? ATM ?ץ??ȥ?????

????

BSD ATM ???եȥ??????ϥͥ??ƥ??֥⡼?? ATM ?ץ??ȥ????ؤ??ޤߡ? AAL0 ?? AAL5 ?β??۲??? (?С??????륵?????å?) ?ؤΥ????åȥ??٥??Υ??????????󶡤??ޤ??? ?ܥץ??ȥ????ؤ?ͭ???ˤ????ˤϡ??????ͥ??????ե???????

options NATM

???ä????????ͥ??κƹ??ۤ??ԤäƤ??????? (???κ? “make clean” ??˺?줺?˹ԤäƤ???????)??

NATM API

NATM ?ؤǤϲ??۲????????ꤹ?뤿???? struct sockaddr_natm ?????Ѥ??ޤ?:

struct sockaddr_natm {
  u_int8_t      snatm_len;              /* Ĺ?? */
  u_int8_t      snatm_family;           /* AF_NATM */
  char          snatm_if[IFNAMSIZ];     /* ???󥿥ե?????̾ */
  u_int16_t     snatm_vci;              /* vci */
  u_int8_t      snatm_vpi;              /* vpi */
};

VPI 0, VCI 201 ?β??۲????? AAL5 ???ͥ??????????????????ˤϼ????ͤˤ??ޤ?:

  struct sockaddr_natm snatm;
  int s, r;
  s = socket(AF_NATM, SOCK_STREAM, PROTO_NATMAAL5);
                       /* ??: PROTO_NATMAAL0 ?? AAL0 ?Ǥ? */
  if (s < 0) { perror("socket"); exit(1); }
  bzero(&snatm, sizeof(snatm));
  snatm.snatm_len = sizeof(snatm);
  snatm.snatm_family = AF_NATM;
  sprintf(snatm.snatm_if, "en0");
  snatm.snatm_vci = 201;
  snatm.snatm_vpi = 0;
  r = connect(s, (struct sockaddr *)&snatm, sizeof(snatm));
  if (r < 0) { perror("connect"); exit(1); }
  /* ?ʾ??? s ?? ATM ????³?????ޤ???! */

socket() ????????ñ????̤??³?? NATM ?????åȤ????????ޤ??? connect() ????????̤??³?? NATM ?????åȤ????۲????˷????դ??? ?ǡ????μ????Τ????ˤ??β??۲?????ͭ???ˤ????褦?ɥ饤?Ф????Τ??ޤ??? connect() ???????μ¹Ը塢???Υ????åȤ??Ф? read() ?ޤ??? write() ?????Ѥ??? ATM ?????Ϥ??Ԥ??ޤ???

?????? NATM ????

????Ū?ˡ?NATM ?ץ??ȥ????ؤ? ???Υ????ƥ????????ƤΥ????ƥ??֤ʲ??۲????Υꥹ?Ȥ? natm_pcbs ???ݻ????Ƥ??ޤ??? ?????ϡ?NATM ?? IP ?????۲??????Ǿ??ͤ??뤳?Ȥ??ɤ??????ˡ? ???λ? IP ?ǻ??????β??????ޤߤޤ???

???۲????Υǡ?????????ͭ???????????ȡ? NATM ?ץ??ȥ????ؤϥץ??ȥ????????֥??å??Υ??ɥ쥹?? ???? “?ϥ??ɥ?” ?Ȥ??ƥɥ饤?Ф??Ϥ??ޤ??? ???ϥǡ????????夹???ȡ? ?ɥ饤?Ф?Ŭ?ڤʼ????ϥ??ɥ??ȶ??˥ǡ??????֤??ޤ??? NATM ?ؤϡ? ?ץ??ȥ????????֥??å??θ????Υ????Хإåɤ??򤱤뤿???ˡ? ???ξ????????Ѥ??ޤ??? ?????ˤ??ꡢATM ?????˥ǡ??????ǥޥ????ץ쥯?????Ƥ??????̤? ???Ѥ??뤳?Ȥ??Ǥ??ޤ???

????¾?? NATM ??????

?桹?ϸ??ߥӥǥ??????Хץ????????Ȥ˼????Ȥ??Ǥ??ꡢ ???ι????ΰ????Ȥ??Ƥ??Υɥ饤?Ф????Ѥ??Ƥ??ޤ??? ?桹?μ긵?ˤϲ桹?κ??????? MMX ?ȸƤФ????ǥХ??????????ޤ??? ?ӥǥ????????? MMX ????³???ơ??ӥǥ????Ϥ? AAL0 ?? ???륹?ȥ꡼???Ȥ????????????뤳?Ȥ??Ǥ??ޤ??? ???????󤳤Υ??ȥ꡼???Ϥ??ʤ?®?? (?ºݤ??????̤Ǥ?!)?? ?ܥɥ饤?Ф??̾??? AAL0 ?ؤν????Ǥ??н??Ǥ??ޤ??? (???????ϡ??????? mbuf ???ȤΥ????򥢥ץꥱ?????????? ?????????褦?Ȼ??ߤ??Ǥ??礦???????????????å??ؤ????μ??? ?ǡ??????ȥ꡼???ν????ˤĤ??Ƥ????ʤ??????狼???ޤ?)?? ?????????????褹?뤿?ᡢ?桹?? “raw” ?⡼?ɤ????????ޤ????? ?????ϡ??????ɤ???????̤?????? AAL0 ?ξ????????礭?ʥǡ????? ?????ޤ??ؤȽ??????ޤ??? ?????å??ؤ????????ʿ????񤤤򤹤뤳??̵???????Υǡ??????ꥢ?륿?????? ?ǥ?????????¸???뤳?Ȥ??Ǥ??ޤ??? ?????ˤ??????Υǡ??????ˤ? RBD (receive buffer descriptors: ?????Хåե????һ?) ?ڤӥ????إå????ޤޤ??Ƥ??ޤ????? ?????ϼ??????߸??˽???ʤ????Фʤ??ޤ????? “raw” ?⡼?ɤ?ͭ?????????ˤϼ????ͤ? ioctl ?????Ѥ??ޤ?:

  int size = 4000; /* bytes */
  ret = ioctl(s, SIOCRAWATM, (caddr_t)&size);

???????Ǥϡ??̾??? 48 ?Х??ȤΤ????ޤ??ǤϤʤ???4000 ?Х??Ȥ? ?????ޤ??? AAL0 ?Υǡ??????????????褦?ɥ饤?Ф??????ޤ??? ???餫?ˤ????Ͼ????ƻ?????ˡ?ǤϤ????ޤ????? ?桹?θ??ߤΥ??ץꥱ?????????ˤ?ɬ?פʤ??ΤǤ??? ???衢Ŭ?????礭?? AAL5 ?Υե졼???ǥӥǥ????󸻤????? ?ǡ??????????Ԥ????뤳?Ȥ????Ԥ??Ƥ??ޤ???

?ٹ?

NATM ?ץ??ȥ????Υ??ݡ??Ȥ? ATM ?ץ??ȥ????γ?ȯ?ˤ??? ?ѹ??????䤹???Ǥ??? ?桼???ϸ??ߤμ????ξܺ٤˰?¸?????٤??ǤϤʤ??? ?ष?????????ݡ??Ȥ??줿?????ӥ??˰?¸???٤??Ǥ???

??Ϣ????

en(4)

????

1996 ǯ??NetBSD ?ˤ????ơ?Washington University ?? Chuck Cranor ?? NATM ?ץ??ȥ????ؤ? EN ATM ?ɥ饤?Фȶ??˼??????ޤ?????