| #include <u.h> |
| #include <libc.h> |
| #include <ip.h> |
| #include "dat.h" |
| #include "protos.h" |
| |
| typedef struct Hdr Hdr; |
| struct Hdr |
| { |
| uchar sport[2]; /* Source port */ |
| uchar dport[2]; /* Destination port */ |
| uchar len[2]; /* data length */ |
| uchar cksum[2]; /* Checksum */ |
| }; |
| |
| enum |
| { |
| UDPLEN= 8 |
| }; |
| |
| enum |
| { |
| Os, |
| Od, |
| Osd, |
| Osetport |
| }; |
| |
| static Field p_fields[] = |
| { |
| {"s", Fnum, Os, "source port", } , |
| {"d", Fnum, Od, "dest port", } , |
| {"a", Fnum, Osd, "source/dest port", } , |
| {"sd", Fnum, Osd, "source/dest port", } , |
| {0} |
| }; |
| |
| #define ANYPORT ~0UL |
| |
| static Mux p_mux[] = |
| { |
| {"bootp", 67, }, |
| {"ninep", 6346, }, /* tvs */ |
| {"dns", 53 }, |
| {"rtp", ANYPORT, }, |
| {"rtcp", ANYPORT, }, |
| {0} |
| }; |
| |
| /* default next protocol, can be changed by p_filter, reset by p_compile */ |
| static Proto *defproto = &dump; |
| |
| static void |
| p_compile(Filter *f) |
| { |
| Mux *m; |
| |
| if(f->op == '='){ |
| compile_cmp(udp.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 = Osd; |
| return; |
| } |
| |
| sysfatal("unknown udp field or protocol: %s", f->s); |
| } |
| |
| static int |
| p_filter(Filter *f, Msg *m) |
| { |
| Hdr *h; |
| |
| if(m->pe - m->ps < UDPLEN) |
| return 0; |
| |
| h = (Hdr*)m->ps; |
| m->ps += UDPLEN; |
| |
| switch(f->subop){ |
| case Os: |
| return NetS(h->sport) == f->ulv; |
| case Od: |
| return NetS(h->dport) == f->ulv; |
| case Osd: |
| if(f->ulv == ANYPORT){ |
| defproto = f->pr; |
| return 1; |
| } |
| return NetS(h->sport) == f->ulv || NetS(h->dport) == f->ulv; |
| } |
| return 0; |
| } |
| |
| static int |
| p_seprint(Msg *m) |
| { |
| Hdr *h; |
| int dport, sport; |
| |
| |
| if(m->pe - m->ps < UDPLEN) |
| return -1; |
| h = (Hdr*)m->ps; |
| m->ps += UDPLEN; |
| |
| /* next protocol */ |
| sport = NetS(h->sport); |
| dport = NetS(h->dport); |
| demux(p_mux, sport, dport, m, defproto); |
| defproto = &dump; |
| |
| m->p = seprint(m->p, m->e, "s=%d d=%d ck=%4.4ux ln=%4d", |
| NetS(h->sport), dport, |
| NetS(h->cksum), NetS(h->len)); |
| return 0; |
| } |
| |
| Proto udp = |
| { |
| "udp", |
| p_compile, |
| p_filter, |
| p_seprint, |
| p_mux, |
| "%lud", |
| p_fields, |
| defaultframer |
| }; |