ref: dc725301592117ad0e70a0ab21926dcf5302ed31
dir: /sys/src/cmd/ip/snoopy/ipmux.c/
#include <u.h> #include <libc.h> #include <ip.h> #include "dat.h" #include "protos.h" typedef struct Hdr Hdr; struct Hdr { uchar ia[16]; uchar data[1]; }; static Mux p_mux[] = { {"ip", 0x40, }, {"ip6", 0x60, }, {0} }; enum { Oia, /* interface address */ Ot, /* ip type */ }; static Field p_fields[] = { {"ia", Fv6ip, Oia, "interface address", }, {"t", Fnum, Ot, "ip type" }, {0} }; static void p_compile(Filter *f) { Mux *m; if(f->op == '='){ compile_cmp(ipmux.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 ipmux field or protocol: %s", f->s); } static int p_filter(Filter *f, Msg *m) { Hdr *h; if(m->pe - m->ps <= 16) return 0; h = (Hdr*)m->ps; m->ps += 16; switch(f->subop){ case Oia: return memcmp(h->ia, f->a, 16) == 0; case Ot: return (h->data[0]&0xF0) == f->ulv; } return 0; } static int p_seprint(Msg *m) { int len; uint t; Hdr *h; len = m->pe - m->ps; if(len <= 16) return -1; h = (Hdr*)m->ps; m->ps += 16; t = h->data[0]&0xF0; demux(p_mux, t, t, m, &dump); m->p = seprint(m->p, m->e, "ia=%I t=%2.2ux ln=%d", h->ia, t, len); return 0; } Proto ipmux = { "ipmux", p_compile, p_filter, p_seprint, p_mux, "%#.2lux", p_fields, defaultframer };