new goodies

src/cmd/ip/snoopy/tcp.c

@@ -0,0 +1,221 @@
+#include <u.h>
+#include <libc.h>
+#include <ip.h>
+#include "dat.h"
+#include "protos.h"
+
+typedef struct Hdr	Hdr;
+struct Hdr
+{
+	uchar	sport[2];
+	uchar	dport[2];
+	uchar	seq[4];
+	uchar	ack[4];
+	uchar	flag[2];
+	uchar	win[2];
+	uchar	cksum[2];
+	uchar	urg[2];
+	uchar	opt[1];
+};
+
+typedef struct PseudoHdr{
+	uchar	src[4];
+	uchar	dst[4];
+	uchar	zero;
+	uchar	proto;
+	uchar	length[2];
+	uchar	hdrdata[1580];
+} PseudoHdr;
+
+enum
+{
+	TCPLEN= 20,
+};
+
+enum
+{
+	Os,
+	Od,
+	Osd,
+};
+
+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}
+};
+
+static Mux p_mux[] =
+{
+	{"ninep",	17007, },	/* exportfs */
+	{"ninep",	564, },		/* 9fs */
+	{"ninep",	17005, },	/* ocpu */
+	{"ninep",	17010, },	/* ncpu */
+	{"ninep",	17013, },	/* cpu */
+	{0},
+};
+
+enum
+{
+	EOLOPT		= 0,
+	NOOPOPT		= 1,
+	MSSOPT		= 2,
+	MSS_LENGTH	= 4,		/* Mean segment size */
+	WSOPT		= 3,
+	WS_LENGTH	= 3,		/* Bits to scale window size by */
+};
+
+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 tcp field or protocol: %s", f->s);
+}
+
+static int
+p_filter(Filter *f, Msg *m)
+{
+	Hdr *h;
+
+	if(m->pe - m->ps < TCPLEN)
+		return 0;
+
+	h = (Hdr*)m->ps;
+	m->ps += ((NetS(h->flag)>>10)&0x3f);
+
+	switch(f->subop){
+	case Os:
+		return NetS(h->sport) == f->ulv;
+	case Od:
+		return NetS(h->dport) == f->ulv;
+	case Osd:
+		return NetS(h->sport) == f->ulv || NetS(h->dport) == f->ulv;
+	}
+	return 0;
+}
+
+enum
+{
+	URG		= 0x20,		/* Data marked urgent */
+	ACK		= 0x10,		/* Aknowledge is valid */
+	PSH		= 0x08,		/* Whole data pipe is pushed */
+	RST		= 0x04,		/* Reset connection */
+	SYN		= 0x02,		/* Pkt. is synchronise */
+	FIN		= 0x01,		/* Start close down */
+};
+
+static char*
+flags(int f)
+{
+	static char fl[20];
+	char *p;
+
+	p = fl;
+	if(f & URG)
+		*p++ = 'U';
+	if(f & ACK)
+		*p++ = 'A';
+	if(f & PSH)
+		*p++ = 'P';
+	if(f & RST)
+		*p++ = 'R';
+	if(f & SYN)
+		*p++ = 'S';
+	if(f & FIN)
+		*p++ = 'F';
+	*p = 0;
+	return fl;
+}
+
+
+static int
+p_seprint(Msg *m)
+{
+	Hdr *h;
+	int dport, sport;
+	int len, flag, optlen;
+	uchar *optr;
+
+	if(m->pe - m->ps < TCPLEN)
+		return -1;
+	h = (Hdr*)m->ps;
+
+	/* get tcp header length */
+	flag = NetS(h->flag);
+	len = (flag>>10)&~3;
+	flag &= 0x3ff;
+	m->ps += len;
+
+	/* next protocol */
+	dport = NetS(h->dport);
+	sport = NetS(h->sport);
+	demux(p_mux, sport, dport, m, &dump);
+
+	m->p = seprint(m->p, m->e, "s=%d d=%d seq=%lud ack=%lud fl=%s win=%d ck=%4.4ux",
+			NetS(h->sport), dport,
+			(ulong)NetL(h->seq), (ulong)NetL(h->ack),
+			flags(flag), NetS(h->win),
+			NetS(h->cksum));
+
+	/* tcp options */
+	len -= TCPLEN;
+	optr = h->opt;
+	while(len > 0) {
+		if(*optr == EOLOPT){
+			m->p = seprint(m->p, m->e, " opt=EOL");
+			break;
+		}
+		if(*optr == NOOPOPT) {
+			m->p = seprint(m->p, m->e, " opt=NOOP");
+			len--;
+			optr++;
+			continue;
+		}
+		optlen = optr[1];
+		if(optlen < 2 || optlen > len)
+			break;
+		switch(*optr) {
+		case MSSOPT:
+			m->p = seprint(m->p, m->e, " opt%d=(mss %ud)", optlen, nhgets(optr+2));
+			break;
+		case WSOPT:
+			m->p = seprint(m->p, m->e, " opt%d=(wscale %ud)", optlen, *(optr+2));
+			break;
+		default:
+			m->p = seprint(m->p, m->e, " opt%d=(%ud %.*H)", optlen, *optr, optlen-2,optr+2);
+		}
+		len -= optlen;
+		optr += optlen;
+	}
+
+	if(Cflag){
+		// editing in progress by ehg
+	}
+	return 0;
+}
+
+Proto tcp =
+{
+	"tcp",
+	p_compile,
+	p_filter,
+	p_seprint,
+	p_mux,
+	p_fields,
+	defaultframer,
+};