Add != operator to snoopy, remove various stupid functions.
 [rsc] --rw-rw-r-- M 1428987 glenda sys 4086 Jan 28 10:50 sys/man/8/snoopy
	/n/sourcesdump/2006/0128/plan9/sys/man/8/snoopy:64,69 - 
	/n/sourcesdump/2006/0129/plan9/sys/man/8/snoopy:64,70
	  .EX
	  \fIexpr\fP:	  \fIprotocol\fP
	  	| \fIfield\fP '=' \fIvalue\fP
	+ 	| \fIfield\fP '!=' \fIvalue\fP
	  	| \fIprotocol\fP '(' \fIexpr\fP ')'
	  	| '(' \fIexpr\fP ')'
	  	| \fIexpr\fP '||' \fIexpr\fP
 [rsc] --rw-rw-r-- M 1428987 glenda sys 8958 Jan 28 10:49 sys/src/cmd/ip/snoopy/dhcp.c
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/dhcp.c:103,120 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/dhcp.c:103,108
	  	OP9auth=		129,	// plan9 auth servers
	  };
	  
	- static void
	- p_compile(Filter *f)
	- {
	- 	sysfatal("unknown bootp field: %s", f->s);
	- }
	- 
	- static int
	- p_filter(Filter *, Msg *)
	- {
	- 	return 0;
	- }
	- 
	  /*
	   *  convert a byte array to hex
	   */
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/dhcp.c:471,478 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/dhcp.c:459,466
	  Proto dhcp =
	  {
	  	"dhcp",
	- 	p_compile,
	- 	p_filter,
	+ 	nil,
	+ 	nil,
	  	p_seprint,
	  	nil,
	  	nil,
 [rsc] --rw-rw-r-- M 1428987 glenda sys 1078 Jan 28 10:49 sys/src/cmd/ip/snoopy/dump.c
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/dump.c:10,21 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/dump.c:10,15
	  {
	  }
	  
	- static int
	- p_filter(Filter *, Msg *)
	- {
	- 	return 0;
	- }
	- 
	  static char tohex[16] = {
	  	'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
	  	'a', 'b', 'c', 'd', 'e', 'f'
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/dump.c:81,87 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/dump.c:75,81
	  {
	  	"dump",
	  	p_compile,
	- 	p_filter,
	+ 	nil,
	  	p_seprint,
	  	nil,
	  	nil,
 [rsc] --rw-rw-r-- M 1428987 glenda sys 1739 Jan 28 10:49 sys/src/cmd/ip/snoopy/filter.y
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/filter.y:12,17 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/filter.y:12,18
	  %term LOR
	  %term LAND
	  %term WORD
	+ %term NE
	  %right '!'
	  %left '|'
	  %left '&'
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/filter.y:27,32 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/filter.y:28,41
	  			{ $$ = $1; }
	  		| WORD '=' WORD
	  			{ $2->l = $1; $2->r = $3; $$ = $2; }
	+ 		| WORD NE WORD
	+ 			{ $2->l = newfilter();
	+ 			  $2->l->op = '=';
	+ 			  $2->l->l = $1;
	+ 			  $2->l->r = $3;
	+ 			  $2->op = '!';
	+ 			  $$ = $2;
	+ 			}
	  		| WORD '(' expr ')'
	  			{ $1->l = $3; free($2); free($4); $$ = $1; }
	  		| '(' expr ')'
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/filter.y:84,100 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/filter.y:93,110
	  	}
	  
	  	yylp++;
	- 	if(*yylp == c)
	- 		switch(c){
	- 		case '&':
	- 			c = LAND;
	- 			yylp++;
	- 			break;
	- 		case '|':
	- 			c = LOR;
	- 			yylp++;
	- 			break;
	- 		}
	+ 	if(c == '!' && *yylp == '='){
	+ 		c = NE;
	+ 		yylp++;
	+ 	}
	+ 	else if(c == '&' && *yylp == '&'){
	+ 		c = LAND;
	+ 		yylp++;
	+ 	}
	+ 	else if(c == '|' && *yylp == '|'){
	+ 		c = LOR;
	+ 		yylp++;
	+ 	}
	  	yylval->op = c;
	  	return c;
	  }
 [rsc] --rw-rw-r-- M 1428987 glenda sys 2261 Jan 28 10:49 sys/src/cmd/ip/snoopy/il.c
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/il.c:102,109 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/il.c:102,108
	  static char*
	  pkttype(int t)
	  {
	- 	char b[10];
	- 
	+ 	static char b[10];
	  	
	  	if(t > 6){
	  		sprint(b, "%d", t);
 [rsc] --rw-rw-r-- M 1428987 glenda sys 15607 Jan 28 10:49 sys/src/cmd/ip/snoopy/main.c
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/main.c:233,239 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/main.c:233,239
	  				return 0;
	  			m->needroot = 0;
	  		}else{
	- 			if(m->pr != nil && !(m->pr->filter)(f, m))
	+ 			if(m->pr && (m->pr->filter==nil || !(m->pr->filter)(f, m)))
	  				return 0;
	  		}
	  		if(f->l == nil)
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/main.c:650,657 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/main.c:650,660
	  		_compile(f->r, last);
	  		break;
	  	case WORD:
	- 		if(last != nil)
	+ 		if(last != nil){
	+ 			if(last->compile == nil)
	+ 				sysfatal("unknown %s subprotocol: %s", f->pr->name, f->s);
	  			(*last->compile)(f);
	+ 		}
	  		if(f->l)
	  			_compile(f->l, f->pr);
	  		break;
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/main.c:658,663 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/main.c:661,669
	  	case '=':
	  		if(last == nil)
	  			sysfatal("internal error: compilewalk: badly formed tree");
	+ 		
	+ 		if(last->compile == nil)
	+ 			sysfatal("unknown %s field: %s", f->pr->name, f->s);
	  		(*last->compile)(f);
	  		break;
	  	default:
 [rsc] --rw-rw-r-- M 1428987 glenda sys 879 Jan 28 10:50 sys/src/cmd/ip/snoopy/mkfile
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/mkfile:53,58 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/mkfile:53,60
	  	main.c\
	  	${POBJS:%.$O=%.c}\
	  
	+ CLEANFILES=protos.c protos.h
	+ 
	  </sys/src/cmd/mkone
	  
	  protos.h: mkfile
 [rsc] --rw-rw-r-- M 1428987 glenda sys 555 Jan 28 10:49 sys/src/cmd/ip/snoopy/ninep.c
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/ninep.c:5,23 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/ninep.c:5,11
	  #include "dat.h"
	  #include "protos.h"
	  
	- static void
	- p_compile(Filter *f)
	- {
	- 	sysfatal("unknown ninep field: %s", f->s);
	- }
	- 
	  static int
	- p_filter(Filter *, Msg *)
	- {
	- 	return 0;
	- }
	- 
	- static int
	  p_seprint(Msg *m)
	  {
	  	Fcall f;
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/ninep.c:44,51 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/ninep.c:32,39
	  Proto ninep =
	  {
	  	"ninep",
	- 	p_compile,
	- 	p_filter,
	+ 	nil,
	+ 	nil,
	  	p_seprint,
	  	nil,
	  	nil,
 [rsc] --rw-rw-r-- M 1428987 glenda sys 7369 Jan 28 10:49 sys/src/cmd/ip/snoopy/ospf.c
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/ospf.c:90,96 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/ospf.c:90,96
	  };
	  
	  char*
	- seprintospfhello(char *p, char *e, void *a, int)
	+ seprintospfhello(char *p, char *e, void *a)
	  {
	  	Ospfhello *h = a;
	  
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/ospf.c:327,344 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/ospf.c:327,332
	  	return seprint(p, e, ")");
	  }
	  
	- static void
	- p_compile(Filter *f)
	- {
	- 	sysfatal("unknown ospf field: %s", f->s);
	- }
	- 
	- static int
	- p_filter(Filter *, Msg *)
	- {
	- 	return 0;
	- }
	- 
	  int
	  p_seprint(Msg *m)
	  {
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/ospf.c:366,372 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/ospf.c:354,360
	  
	  	switch (ospf->type) {
	  	case OSPFhello:
	- 		p = seprintospfhello(p, e, ospf->data, x);
	+ 		p = seprintospfhello(p, e, ospf->data);
	  		break;
	  	case OSPFdd:
	  		p = seprintospfdatadesc(p, e, ospf->data, x);
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/ospf.c:392,399 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/ospf.c:380,387
	  Proto ospf =
	  {
	  	"ospf",
	- 	p_compile,
	- 	p_filter,
	+ 	nil,
	+ 	nil,
	  	p_seprint,
	  	nil,
	  	nil,
 [rsc] --rw-rw-r-- M 1428987 jmk sys 1818 Jan 28 10:49 sys/src/cmd/ip/snoopy/rtcp.c
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/rtcp.c:31,50 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/rtcp.c:31,37
	  	REPORTLEN = 24,
	  };
	  
	- 
	- static void
	- p_compile(Filter *f)
	- {
	- 	sysfatal("unknown rtcp field: %s", f->s);
	- }
	- 
	  static int
	- p_filter(Filter *, Msg *)
	- {
	- 	return 0;
	- }
	- 
	- static int
	  p_seprint(Msg *m)
	  {
	  	Hdr*h;
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/rtcp.c:86,93 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/rtcp.c:73,80
	  
	  Proto rtcp = {
	  	"rtcp",
	- 	p_compile,
	- 	p_filter,
	+ 	nil,
	+ 	nil,
	  	p_seprint,
	  	nil,
	  	nil,
 [rsc] --rw-rw-r-- M 1428987 jmk sys 1021 Jan 28 10:49 sys/src/cmd/ip/snoopy/rtp.c
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/rtp.c:17,36 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/rtp.c:17,23
	  	RTPLEN = 12,		// Minimum size of an RTP header
	  };
	  
	- 
	- static void
	- p_compile(Filter *f)
	- {
	- 	sysfatal("unknown rtp field: %s", f->s);
	- }
	- 
	  static int
	- p_filter(Filter *, Msg *)
	- {
	- 	return 0;
	- }
	- 
	- static int
	  p_seprint(Msg *m)
	  {
	  	Hdr*h;
	/n/sourcesdump/2006/0128/plan9/sys/src/cmd/ip/snoopy/rtp.c:65,72 - 
	/n/sourcesdump/2006/0129/plan9/sys/src/cmd/ip/snoopy/rtp.c:52,59
	  
	  Proto rtp = {
	  	"rtp",
	- 	p_compile,
	- 	p_filter,
	+ 	nil,
	+ 	nil,
	  	p_seprint,
	  	nil,
	  	nil,