ref: 34f5a8333090c5090e1d0b6ddbaf900d64340eea
dir: /sys/src/cmd/ip/snoopy/ether.c/
#include <u.h> #include <libc.h> #include <ip.h> #include "dat.h" #include "protos.h" typedef struct Hdr Hdr; struct Hdr { uchar d[6]; uchar s[6]; uchar type[2]; char data[1500]; }; #define ETHERMINTU 60 /* minimum transmit size */ #define ETHERMAXTU 1514 /* maximum transmit size */ #define ETHERHDRSIZE 14 /* size of an ethernet header */ static Mux p_mux[] = { {"ip", 0x0800, } , {"arp", 0x0806, } , {"rarp", 0x0806, } , {"ip6", 0x86dd, } , {"pppoe_disc", 0x8863, }, {"pppoe_sess", 0x8864, }, {"eapol", 0x888e, }, {"aoe", 0x88a2, } , {"cec", 0xbcbc, } , {0} }; enum { Os, /* source */ Od, /* destination */ Oa, /* source or destination */ Ot, /* type */ }; static Field p_fields[] = { {"s", Fether, Os, "source address", } , {"d", Fether, Od, "destination address", } , {"a", Fether, Oa, "source|destination address" } , {"sd", Fether, Oa, "source|destination address" } , {"t", Fnum, Ot, "type" } , {0} }; static void p_compile(Filter *f) { Mux *m; if(f->op == '='){ compile_cmp(ether.name, f, p_fields); return; } for(m = p_mux; m->name != nil; m++) if(strcmp(f->s, m->name) == 0){ f->pr = m->pr; f->ulv = m->val; f->subop = Ot; return; } sysfatal("unknown ethernet field or protocol: %s", f->s); } static int p_filter(Filter *f, Msg *m) { Hdr *h; if(m->pe - m->ps < ETHERHDRSIZE) return 0; h = (Hdr*)m->ps; m->ps += ETHERHDRSIZE; switch(f->subop){ case Os: return memcmp(h->s, f->a, 6) == 0; case Od: return memcmp(h->d, f->a, 6) == 0; case Oa: return memcmp(h->s, f->a, 6) == 0 || memcmp(h->d, f->a, 6) == 0; case Ot: return NetS(h->type) == f->ulv; } return 0; } static int p_seprint(Msg *m) { int len; uint t; Hdr *h; len = m->pe - m->ps; if(len < ETHERHDRSIZE) return -1; h = (Hdr*)m->ps; m->ps += ETHERHDRSIZE; t = NetS(h->type); demux(p_mux, t, t, m, &dump); m->p = seprint(m->p, m->e, "s=%E d=%E pr=%4.4ux ln=%d", h->s, h->d, t, len); return 0; } Proto ether = { "ether", p_compile, p_filter, p_seprint, p_mux, "%#.4lux", p_fields, defaultframer };