ref: c1d40df49550393f3afe53fb6e6d500dfa8eb7a8
dir: /sys/src/cmd/ip/snoopy/pppoe_disc.c/
#include <u.h> #include <libc.h> #include <ip.h> #include "dat.h" #include "protos.h" typedef struct Hdr Hdr; struct Hdr { uchar verstype; uchar code; uchar sessid[2]; uchar length[2]; /* of payload */ }; enum { HDRSIZE = 1+1+2+2 }; static Mux p_mux[] = { {"ppp", 0, } , {0} }; enum { Overs, Otype, Ocode, Osess, }; static Field p_fields[] = { {"v", Fnum, Overs, "version", } , {"t", Fnum, Otype, "type", } , {"c", Fnum, Ocode, "code" } , {"s", Fnum, Osess, "sessid" } , {0} }; static void p_compilesess(Filter *f) { // Mux *m; if(f->op == '='){ compile_cmp(pppoe_sess.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 pppoe field or protocol: %s", f->s); } static void p_compiledisc(Filter *f) { // Mux *m; if(f->op == '='){ compile_cmp(pppoe_disc.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 pppoe field or protocol: %s", f->s); } static int p_filter(Filter *f, Msg *m) { Hdr *h; if(m->pe - m->ps < HDRSIZE) return 0; h = (Hdr*)m->ps; m->ps += HDRSIZE; switch(f->subop){ case Overs: return (h->verstype>>4) == f->ulv; case Otype: return (h->verstype&0xF) == f->ulv; case Ocode: return h->code == f->ulv; case Osess: return NetS(h->sessid) == f->ulv; } return 0; } /* BUG: print all the discovery types */ static int p_seprintdisc(Msg *m) { Hdr *h; int len; len = m->pe - m->ps; if(len < HDRSIZE) return -1; h = (Hdr*)m->ps; m->ps += HDRSIZE; m->pr = nil; m->p = seprint(m->p, m->e, "v=%d t=%d c=0x%x s=0x%ux, len=%d", h->verstype>>4, h->verstype&0xF, h->code, NetS(h->sessid), NetS(h->length)); return 0; } static int p_seprintsess(Msg *m) { Hdr *h; int len; len = m->pe - m->ps; if(len < HDRSIZE) return -1; h = (Hdr*)m->ps; m->ps += HDRSIZE; /* this will call ppp for me */ demux(p_mux, 0, 0, m, &dump); m->p = seprint(m->p, m->e, "v=%d t=%d c=0x%x s=0x%ux, len=%d", h->verstype>>4, h->verstype&0xF, h->code, NetS(h->sessid), NetS(h->length)); return 0; } Proto pppoe_disc = { "pppoe_disc", p_compiledisc, p_filter, p_seprintdisc, p_mux, "%lud", p_fields, defaultframer }; Proto pppoe_sess = { "pppoe_sess", p_compilesess, p_filter, p_seprintsess, p_mux, "%lud", p_fields, defaultframer };