plan9port

fork of plan9port with libvec, libstr and libsdb
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ether.c (2024B)

      1 #include <u.h>
      2 #include <libc.h>
      3 #include <ip.h>
      4 #include "dat.h"
      5 #include "protos.h"
      6 
      7 typedef struct Hdr	Hdr;
      8 struct Hdr {
      9 	uchar d[6];
     10 	uchar s[6];
     11 	uchar type[2];
     12 	char data[1500];
     13 };
     14 #define	ETHERMINTU	60	/* minimum transmit size */
     15 #define	ETHERMAXTU	1514	/* maximum transmit size */
     16 #define ETHERHDRSIZE	14	/* size of an ethernet header */
     17 
     18 static Mux p_mux[] =
     19 {
     20 	{"ip",		0x0800,	} ,
     21 	{"arp",		0x0806,	} ,
     22 	{"rarp",	0x0806,	} ,
     23 	{"ip6", 	0x86dd, } ,
     24 	{"pppoe_disc",	0x8863, },
     25 	{"pppoe_sess",	0x8864, },
     26 	{"eapol",	0x888e, },
     27 	{0}
     28 };
     29 
     30 enum
     31 {
     32 	Os,	/* source */
     33 	Od,	/* destination */
     34 	Oa,	/* source or destination */
     35 	Ot,	/* type */
     36 };
     37 
     38 static Field p_fields[] =
     39 {
     40 	{"s",	Fether,	Os,	"source address",	} ,
     41 	{"d",	Fether,	Od,	"destination address",	} ,
     42 	{"a",	Fether,	Oa,	"source|destination address" } ,
     43 	{"sd",	Fether,	Oa,	"source|destination address" } ,
     44 	{"t",	Fnum,	Ot,	"type" } ,
     45 	{0}
     46 };
     47 
     48 static void
     49 p_compile(Filter *f)
     50 {
     51 	Mux *m;
     52 
     53 	if(f->op == '='){
     54 		compile_cmp(ether.name, f, p_fields);
     55 		return;
     56 	}
     57 	for(m = p_mux; m->name != nil; m++)
     58 		if(strcmp(f->s, m->name) == 0){
     59 			f->pr = m->pr;
     60 			f->ulv = m->val;
     61 			f->subop = Ot;
     62 			return;
     63 		}
     64 	sysfatal("unknown ethernet field or protocol: %s", f->s);
     65 }
     66 
     67 static int
     68 p_filter(Filter *f, Msg *m)
     69 {
     70 	Hdr *h;
     71 
     72 	if(m->pe - m->ps < ETHERHDRSIZE)
     73 		return 0;
     74 
     75 	h = (Hdr*)m->ps;
     76 	m->ps += ETHERHDRSIZE;
     77 
     78 	switch(f->subop){
     79 	case Os:
     80 		return !memcmp(h->s, f->a, 6);
     81 	case Od:
     82 		return !memcmp(h->d, f->a, 6);
     83 	case Oa:
     84 		return memcmp(h->s, f->a, 6) == 0 || memcmp(h->d, f->a, 6) == 0;
     85 	case Ot:
     86 		return NetS(h->type) == f->ulv;
     87 	}
     88 	return 0;
     89 }
     90 
     91 static int
     92 p_seprint(Msg *m)
     93 {
     94 	Hdr *h;
     95 	uint t;
     96 	int len;
     97 
     98 	len = m->pe - m->ps;
     99 	if(len < ETHERHDRSIZE)
    100 		return -1;
    101 
    102 	h = (Hdr*)m->ps;
    103 	m->ps += ETHERHDRSIZE;
    104 
    105 	t = NetS(h->type);
    106 	demux(p_mux, t, t, m, &dump);
    107 
    108 	m->p = seprint(m->p, m->e, "s=%E d=%E pr=%4.4ux ln=%d", h->s, h->d,
    109 		t, len);
    110 	return 0;
    111 }
    112 
    113 Proto ether =
    114 {
    115 	"ether",
    116 	p_compile,
    117 	p_filter,
    118 	p_seprint,
    119 	p_mux,
    120 	"%#.4lux",
    121 	p_fields,
    122 	defaultframer
    123 };