ref: 20a1d2268d69a0bbe66d0f21999649133878377c
dir: /sys/src/cmd/ip/snoopy/ippkt.c/
#include <u.h> #include <libc.h> #include <ip.h> #include "dat.h" #include "protos.h" static Mux p_mux[] = { {"ip", 0x40, }, {"ip6", 0x60, }, {0} }; enum { Ot, /* ip type */ }; static Field p_fields[] = { {"t", Fnum, Ot, "ip type" }, {0} }; static void p_compile(Filter *f) { Mux *m; if(f->op == '='){ compile_cmp(ippkt.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 ippkt field or protocol: %s", f->s); } static int p_filter(Filter *f, Msg *m) { if(m->ps >= m->pe) return 0; switch(f->subop){ case Ot: return (m->ps[0]&0xF0) == f->ulv; } return 0; } static int p_seprint(Msg *m) { uint t; if(m->ps >= m->pe) return -1; t = m->ps[0]&0xF0; demux(p_mux, t, t, m, &dump); m->p = seprint(m->p, m->e, "t=%2.2ux", t); return 0; } Proto ippkt = { "ippkt", p_compile, p_filter, p_seprint, p_mux, "%#.2lux", p_fields, defaultframer };