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