freebsd-skq/usr.sbin/mrouted/cfparse.y
kris aec252afab String buffer safety cleanup. I don't think any of these were exploitable
remotely, but they would be if e.g. it happened to call the logging
function using a DNS hostname.

Also replace random() by arc4random() - only one of these is arguably
required since it's directly used in the protocol, but we might as
well replace both to avoid using two different PRNGs.

Reviewed by:	green, alex
2000-10-09 06:08:00 +00:00

933 lines
19 KiB
Plaintext

%{
/*
* Configuration file parser for mrouted.
*
* Written by Bill Fenner, NRL, 1994
*
* $FreeBSD$
* cfparse.y,v 3.8.4.30 1998/03/01 01:48:58 fenner Exp
*/
#include <stdio.h>
#ifdef __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#include "defs.h"
#include <netdb.h>
/*
* Local function declarations
*/
static void fatal __P((char *fmt, ...));
static void warn __P((char *fmt, ...));
static void yyerror __P((char *s));
static char * next_word __P((void));
static int yylex __P((void));
static u_int32 valid_if __P((char *s));
static struct ifreq * ifconfaddr __P((struct ifconf *ifcp, u_int32 a));
int yyparse __P((void));
static FILE *f;
char *configfilename = _PATH_MROUTED_CONF;
extern int cache_lifetime;
extern int prune_lifetime;
/* imported from config.c, with slight memory leak */
extern struct ifconf ifc;
int allow_black_holes = 0;
static int lineno;
static struct uvif *v;
static int order, state;
static int noflood = 0;
static int rexmit = VIFF_REXMIT_PRUNES;
struct addrmask {
u_int32 addr;
int mask;
};
struct boundnam {
char *name;
struct addrmask bound;
};
#define MAXBOUNDS 20
struct boundnam boundlist[MAXBOUNDS]; /* Max. of 20 named boundaries */
int numbounds = 0; /* Number of named boundaries */
%}
%union
{
int num;
char *ptr;
struct addrmask addrmask;
u_int32 addr;
struct vf_element *filterelem;
};
%token CACHE_LIFETIME PRUNE_LIFETIME PRUNING BLACK_HOLE NOFLOOD
%token PHYINT TUNNEL NAME
%token DISABLE IGMPV1 SRCRT BESIDE
%token METRIC THRESHOLD RATE_LIMIT BOUNDARY NETMASK ALTNET ADVERT_METRIC
%token FILTER ACCEPT DENY EXACT BIDIR REXMIT_PRUNES REXMIT_PRUNES2
%token PASSIVE ALLOW_NONPRUNERS
%token NOTRANSIT BLASTER FORCE_LEAF
%token PRUNE_LIFETIME2 NOFLOOD2
%token SYSNAM SYSCONTACT SYSVERSION SYSLOCATION
%token <num> BOOLEAN
%token <num> NUMBER
%token <ptr> STRING
%token <addrmask> ADDRMASK
%token <addr> ADDR
%type <addr> interface addrname
%type <addrmask> bound boundary addrmask
%type <filterelem> filter filtlist filtelement filtelem
%start conf
%%
conf : stmts
;
stmts : /* Empty */
| stmts stmt
;
stmt : error
| PHYINT interface {
vifi_t vifi;
state++;
if (order)
fatal("phyints must appear before tunnels");
for (vifi = 0, v = uvifs;
vifi < numvifs;
++vifi, ++v)
if (!(v->uv_flags & VIFF_TUNNEL) &&
$2 == v->uv_lcl_addr)
break;
if (vifi == numvifs)
fatal("%s is not a configured interface",
inet_fmt($2,s1));
}
ifmods
| TUNNEL interface addrname {
struct ifreq *ifr;
struct ifreq ffr;
vifi_t vifi;
order++;
ifr = ifconfaddr(&ifc, $2);
if (ifr == 0)
fatal("Tunnel local address %s is not mine",
inet_fmt($2, s1));
if (((ntohl($2) & IN_CLASSA_NET) >> IN_CLASSA_NSHIFT) ==
IN_LOOPBACKNET)
fatal("Tunnel local address %s is a loopback address",
inet_fmt($2, s1));
if (ifconfaddr(&ifc, $3) != 0)
fatal("Tunnel remote address %s is one of mine",
inet_fmt($3, s1));
for (vifi = 0, v = uvifs;
vifi < numvifs;
++vifi, ++v)
if (v->uv_flags & VIFF_TUNNEL) {
if ($3 == v->uv_rmt_addr)
fatal("Duplicate tunnel to %s",
inet_fmt($3, s1));
} else if (!(v->uv_flags & VIFF_DISABLED)) {
if (($3 & v->uv_subnetmask) == v->uv_subnet)
fatal("Unnecessary tunnel to %s, same subnet as vif %d (%s)",
inet_fmt($3,s1), vifi, v->uv_name);
}
if (numvifs == MAXVIFS)
fatal("too many vifs");
strncpy(ffr.ifr_name, ifr->ifr_name, IFNAMSIZ);
if (ioctl(udp_socket, SIOCGIFFLAGS, (char *)&ffr)<0)
fatal("ioctl SIOCGIFFLAGS on %s", ffr.ifr_name);
v = &uvifs[numvifs];
zero_vif(v, 1);
v->uv_flags = VIFF_TUNNEL | rexmit | noflood;
v->uv_flags |= VIFF_OTUNNEL; /*XXX*/
v->uv_lcl_addr = $2;
v->uv_rmt_addr = $3;
v->uv_dst_addr = $3;
strncpy(v->uv_name, ffr.ifr_name, IFNAMSIZ);
v->uv_name[IFNAMSIZ-1]='\0';
if (!(ffr.ifr_flags & IFF_UP)) {
v->uv_flags |= VIFF_DOWN;
vifs_down = TRUE;
}
}
tunnelmods
{
if (!(v->uv_flags & VIFF_OTUNNEL)) {
init_ipip_on_vif(v);
}
log(LOG_INFO, 0,
"installing tunnel from %s to %s as vif #%u - rate=%d",
inet_fmt($2, s1), inet_fmt($3, s2),
numvifs, v->uv_rate_limit);
++numvifs;
}
| CACHE_LIFETIME NUMBER {
if ($2 < MIN_CACHE_LIFETIME) {
warn("cache_lifetime %d must be at least %d",
$2, MIN_CACHE_LIFETIME);
} else {
cache_lifetime = $2;
}
}
| PRUNE_LIFETIME NUMBER {
if ($2 < MIN_PRUNE_LIFETIME) {
warn("prune_lifetime %d must be at least %d",
$2, MIN_PRUNE_LIFETIME);
} else {
prune_lifetime = $2;
}
}
| PRUNING BOOLEAN {
if ($2 != 1) {
warn("Disabling pruning is no longer supported");
}
}
| BLACK_HOLE {
#ifdef ALLOW_BLACK_HOLES
allow_black_holes = 1;
#endif
}
/*
* Turn off initial flooding (until subordinateness is learned
* via route exchange) on all phyints and set the default for
* all further tunnels.
*/
| NOFLOOD {
vifi_t vifi;
noflood = VIFF_NOFLOOD;
for (vifi = 0, v = uvifs;
vifi < numvifs;
++vifi, ++v)
v->uv_flags |= VIFF_NOFLOOD;
}
/*
* Turn on prune retransmission on all interfaces.
* Tunnels default to retransmitting, so this just
* needs to turn on phyints.
*/
| REXMIT_PRUNES {
vifi_t vifi;
for (vifi = 0, v = uvifs;
vifi < numvifs;
++vifi, ++v)
v->uv_flags |= VIFF_REXMIT_PRUNES;
}
/*
* If true, do as above. If false, no need to turn
* it off for phyints since they default to not
* rexmit; need to set flag to not rexmit on tunnels.
*/
| REXMIT_PRUNES BOOLEAN {
if ($2) {
vifi_t vifi;
for (vifi = 0, v = uvifs;
vifi < numvifs;
++vifi, ++v)
v->uv_flags |= VIFF_REXMIT_PRUNES;
} else {
rexmit = 0;
}
}
| NAME STRING boundary { if (numbounds >= MAXBOUNDS) {
fatal("Too many named boundaries (max %d)", MAXBOUNDS);
}
boundlist[numbounds].name = malloc(strlen($2) + 1);
strcpy(boundlist[numbounds].name, $2);
boundlist[numbounds++].bound = $3;
}
| SYSNAM STRING {
#ifdef SNMP
set_sysName($2);
#endif /* SNMP */
}
| SYSCONTACT STRING {
#ifdef SNMP
set_sysContact($2);
#endif /* SNMP */
}
| SYSVERSION STRING {
#ifdef SNMP
set_sysVersion($2);
#endif /* SNMP */
}
| SYSLOCATION STRING {
#ifdef SNMP
set_sysLocation($2);
#endif /* SNMP */
}
;
tunnelmods : /* empty */
| tunnelmods tunnelmod
;
tunnelmod : mod
| BESIDE { v->uv_flags |= VIFF_OTUNNEL; }
| BESIDE BOOLEAN {
if ($2) {
v->uv_flags |= VIFF_OTUNNEL;
} else {
v->uv_flags &= ~VIFF_OTUNNEL;
}
}
| SRCRT { fatal("Source-route tunnels not supported"); }
;
ifmods : /* empty */
| ifmods ifmod
;
ifmod : mod
| DISABLE { v->uv_flags |= VIFF_DISABLED; }
| IGMPV1 { v->uv_flags |= VIFF_IGMPV1; }
| NETMASK addrname {
u_int32 subnet, mask;
mask = $2;
subnet = v->uv_lcl_addr & mask;
if (!inet_valid_subnet(subnet, mask))
fatal("Invalid netmask");
v->uv_subnet = subnet;
v->uv_subnetmask = mask;
v->uv_subnetbcast = subnet | ~mask;
}
| NETMASK {
warn("Expected address after netmask keyword, ignored");
}
| ALTNET addrmask {
struct phaddr *ph;
ph = (struct phaddr *)malloc(sizeof(struct phaddr));
if (ph == NULL)
fatal("out of memory");
if ($2.mask) {
VAL_TO_MASK(ph->pa_subnetmask, $2.mask);
} else
ph->pa_subnetmask = v->uv_subnetmask;
ph->pa_subnet = $2.addr & ph->pa_subnetmask;
ph->pa_subnetbcast = ph->pa_subnet | ~ph->pa_subnetmask;
if ($2.addr & ~ph->pa_subnetmask)
warn("Extra subnet %s/%d has host bits set",
inet_fmt($2.addr,s1), $2.mask);
ph->pa_next = v->uv_addrs;
v->uv_addrs = ph;
}
| ALTNET {
warn("Expected address after altnet keyword, ignored");
}
| FORCE_LEAF {
v->uv_flags |= VIFF_FORCE_LEAF;
}
| FORCE_LEAF BOOLEAN {
if ($2) {
v->uv_flags |= VIFF_FORCE_LEAF;
} else {
v->uv_flags &= ~VIFF_FORCE_LEAF;
}
}
;
mod : THRESHOLD NUMBER { if ($2 < 1 || $2 > 255)
fatal("Invalid threshold %d",$2);
v->uv_threshold = $2;
}
| THRESHOLD {
warn("Expected number after threshold keyword, ignored");
}
| METRIC NUMBER { if ($2 < 1 || $2 > UNREACHABLE)
fatal("Invalid metric %d",$2);
v->uv_metric = $2;
}
| METRIC {
warn("Expected number after metric keyword, ignored");
}
| ADVERT_METRIC NUMBER { if ($2 < 0 || $2 > UNREACHABLE - 1)
fatal("Invalid advert_metric %d", $2);
v->uv_admetric = $2;
}
| ADVERT_METRIC {
warn("Expected number after advert_metric keyword, ignored");
}
| RATE_LIMIT NUMBER { if ($2 > MAX_RATE_LIMIT)
fatal("Invalid rate_limit %d",$2);
v->uv_rate_limit = $2;
}
| RATE_LIMIT {
warn("Expected number after rate_limit keyword, ignored");
}
| BOUNDARY bound {
struct vif_acl *v_acl;
v_acl = (struct vif_acl *)malloc(sizeof(struct vif_acl));
if (v_acl == NULL)
fatal("out of memory");
VAL_TO_MASK(v_acl->acl_mask, $2.mask);
v_acl->acl_addr = $2.addr & v_acl->acl_mask;
if ($2.addr & ~v_acl->acl_mask)
warn("Boundary spec %s/%d has host bits set",
inet_fmt($2.addr,s1),$2.mask);
v_acl->acl_next = v->uv_acl;
v->uv_acl = v_acl;
}
| BOUNDARY {
warn("Expected boundary spec after boundary keyword, ignored");
}
| REXMIT_PRUNES2 {
v->uv_flags |= VIFF_REXMIT_PRUNES;
}
| REXMIT_PRUNES2 BOOLEAN {
if ($2) {
v->uv_flags |= VIFF_REXMIT_PRUNES;
} else {
v->uv_flags &= ~VIFF_REXMIT_PRUNES;
}
}
| PASSIVE {
v->uv_flags |= VIFF_PASSIVE;
}
| NOFLOOD2 {
v->uv_flags |= VIFF_NOFLOOD;
}
| NOTRANSIT {
v->uv_flags |= VIFF_NOTRANSIT;
}
| BLASTER {
v->uv_flags |= VIFF_BLASTER;
blaster_alloc(v - uvifs);
}
| ALLOW_NONPRUNERS {
v->uv_flags |= VIFF_ALLOW_NONPRUNERS;
}
| PRUNE_LIFETIME2 NUMBER {
if ($2 < MIN_PRUNE_LIFETIME) {
warn("prune_lifetime %d must be at least %d",
$2, MIN_PRUNE_LIFETIME);
} else {
v->uv_prune_lifetime = $2;
}
}
| ACCEPT filter {
if (v->uv_filter == NULL) {
struct vif_filter *v_filter;
v_filter = (struct vif_filter *)malloc(sizeof(struct vif_filter));
if (v_filter == NULL)
fatal("out of memory");
v_filter->vf_flags = 0;
v_filter->vf_type = VFT_ACCEPT;
v_filter->vf_filter = $2;
v->uv_filter = v_filter;
} else if (v->uv_filter->vf_type != VFT_ACCEPT) {
fatal("can't accept and deny");
} else {
struct vf_element *p;
p = v->uv_filter->vf_filter;
while (p->vfe_next)
p = p->vfe_next;
p->vfe_next = $2;
}
}
| ACCEPT {
warn("Expected filter spec after accept keyword, ignored");
}
| DENY filter {
if (v->uv_filter == NULL) {
struct vif_filter *v_filter;
v_filter = (struct vif_filter *)malloc(sizeof(struct vif_filter));
if (v_filter == NULL)
fatal("out of memory");
v_filter->vf_flags = 0;
v_filter->vf_type = VFT_DENY;
v_filter->vf_filter = $2;
v->uv_filter = v_filter;
} else if (v->uv_filter->vf_type != VFT_DENY) {
fatal("can't accept and deny");
} else {
struct vf_element *p;
p = v->uv_filter->vf_filter;
while (p->vfe_next)
p = p->vfe_next;
p->vfe_next = $2;
}
}
| DENY {
warn("Expected filter spec after deny keyword, ignored");
}
| BIDIR {
if (v->uv_filter == NULL) {
fatal("bidir goes after filters");
}
v->uv_filter->vf_flags |= VFF_BIDIR;
}
;
interface : ADDR { $$ = $1; }
| STRING {
$$ = valid_if($1);
if ($$ == 0)
fatal("Invalid interface name %s",$1);
}
;
addrname : ADDR { $$ = $1; }
| STRING { struct hostent *hp;
if ((hp = gethostbyname($1)) == NULL ||
hp->h_length != sizeof($$))
fatal("No such host %s", $1);
if (hp->h_addr_list[1])
fatal("Hostname %s does not %s",
$1, "map to a unique address");
bcopy(hp->h_addr_list[0], &$$,
hp->h_length);
}
bound : boundary { $$ = $1; }
| STRING { int i;
for (i=0; i < numbounds; i++) {
if (!strcmp(boundlist[i].name, $1)) {
$$ = boundlist[i].bound;
break;
}
}
if (i == numbounds) {
fatal("Invalid boundary name %s",$1);
}
}
;
boundary : ADDRMASK {
#ifdef ALLOW_BLACK_HOLES
if (!allow_black_holes)
#endif
if ((ntohl($1.addr) & 0xff000000) != 0xef000000) {
fatal("Boundaries must be 239.x.x.x, not %s/%d",
inet_fmt($1.addr, s1), $1.mask);
}
$$ = $1;
}
;
addrmask : ADDRMASK { $$ = $1; }
| ADDR { $$.addr = $1; $$.mask = 0; }
;
filter : filtlist { $$ = $1; }
| STRING { fatal("named filters no implemented yet"); }
;
filtlist : filtelement { $$ = $1; }
| filtelement filtlist { $1->vfe_next = $2; $$ = $1; }
;
filtelement : filtelem { $$ = $1; }
| filtelem EXACT { $1->vfe_flags |= VFEF_EXACT; $$ = $1; }
;
filtelem : ADDRMASK {
struct vf_element *vfe;
vfe = (struct vf_element *)malloc(sizeof(struct vf_element));
if (vfe == NULL)
fatal("out of memory");
vfe->vfe_addr = $1.addr;
VAL_TO_MASK(vfe->vfe_mask, $1.mask);
vfe->vfe_flags = 0;
vfe->vfe_next = NULL;
$$ = vfe;
}
%%
#ifdef __STDC__
static void
fatal(char *fmt, ...)
{
va_list ap;
char buf[MAXHOSTNAMELEN + 100];
va_start(ap, fmt);
#else
/*VARARGS1*/
static void
fatal(fmt, va_alist)
char *fmt;
va_dcl
{
va_list ap;
char buf[MAXHOSTNAMELEN + 100];
va_start(ap);
#endif
vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
log(LOG_ERR,0,"%s: %s near line %d", configfilename, buf, lineno);
}
#ifdef __STDC__
static void
warn(char *fmt, ...)
{
va_list ap;
char buf[200];
va_start(ap, fmt);
#else
/*VARARGS1*/
static void
warn(fmt, va_alist)
char *fmt;
va_dcl
{
va_list ap;
char buf[200];
va_start(ap);
#endif
vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
log(LOG_WARNING,0,"%s: %s near line %d", configfilename, buf, lineno);
}
static void
yyerror(s)
char *s;
{
log(LOG_ERR, 0, "%s: %s near line %d", configfilename, s, lineno);
}
static char *
next_word()
{
static char buf[1024];
static char *p=NULL;
char *q;
while (1) {
if (!p || !*p) {
lineno++;
if (fgets(buf, sizeof(buf), f) == NULL)
return NULL;
p = buf;
}
while (*p && (*p == ' ' || *p == '\t')) /* skip whitespace */
p++;
if (*p == '#') {
p = NULL; /* skip comments */
continue;
}
q = p;
#ifdef SNMP
if (*p == '"') {
p++;
while (*p && *p != '"' && *p != '\n')
p++; /* find next whitespace */
if (*p == '"')
p++;
} else
#endif
while (*p && *p != ' ' && *p != '\t' && *p != '\n')
p++; /* find next whitespace */
*p++ = '\0'; /* null-terminate string */
if (!*q) {
p = NULL;
continue; /* if 0-length string, read another line */
}
return q;
}
}
/*
* List of keywords. Must have an empty record at the end to terminate
* list. If a second value is specified, the first is used at the beginning
* of the file and the second is used while parsing interfaces (e.g. after
* the first "phyint" or "tunnel" keyword).
*/
static struct keyword {
char *word;
int val1;
int val2;
} words[] = {
{ "cache_lifetime", CACHE_LIFETIME },
{ "prune_lifetime", PRUNE_LIFETIME, PRUNE_LIFETIME2 },
{ "pruning", PRUNING },
{ "phyint", PHYINT },
{ "tunnel", TUNNEL },
{ "disable", DISABLE },
{ "metric", METRIC },
{ "advert_metric", ADVERT_METRIC },
{ "threshold", THRESHOLD },
{ "rate_limit", RATE_LIMIT },
{ "force_leaf", FORCE_LEAF },
{ "srcrt", SRCRT },
{ "sourceroute", SRCRT },
{ "boundary", BOUNDARY },
{ "netmask", NETMASK },
{ "igmpv1", IGMPV1 },
{ "altnet", ALTNET },
{ "name", NAME },
{ "accept", ACCEPT },
{ "deny", DENY },
{ "exact", EXACT },
{ "bidir", BIDIR },
{ "allow_nonpruners", ALLOW_NONPRUNERS },
#ifdef ALLOW_BLACK_HOLES
{ "allow_black_holes", BLACK_HOLE },
#endif
{ "noflood", NOFLOOD, NOFLOOD2},
{ "notransit", NOTRANSIT },
{ "blaster", BLASTER },
{ "rexmit_prunes", REXMIT_PRUNES, REXMIT_PRUNES2 },
{ "passive", PASSIVE },
{ "beside", BESIDE },
#ifdef SNMP
{ "sysName", SYSNAM },
{ "sysContact", SYSCONTACT },
{ "sysVersion", SYSVERSION },
{ "sysLocation", SYSLOCATION },
#endif
{ NULL, 0 }
};
static int
yylex()
{
int n;
u_int32 addr;
char *q;
struct keyword *w;
if ((q = next_word()) == NULL) {
return 0;
}
for (w = words; w->word; w++)
if (!strcmp(q, w->word))
return (state && w->val2) ? w->val2 : w->val1;
if (!strcmp(q,"on") || !strcmp(q,"yes")) {
yylval.num = 1;
return BOOLEAN;
}
if (!strcmp(q,"off") || !strcmp(q,"no")) {
yylval.num = 0;
return BOOLEAN;
}
if (!strcmp(q,"default")) {
yylval.addrmask.mask = 0;
yylval.addrmask.addr = 0;
return ADDRMASK;
}
if (sscanf(q,"%[.0-9]/%d%c",s1,&n,s2) == 2) {
if ((addr = inet_parse(s1,1)) != 0xffffffff) {
yylval.addrmask.mask = n;
yylval.addrmask.addr = addr;
return ADDRMASK;
}
/* fall through to returning STRING */
}
if (sscanf(q,"%[.0-9]%c",s1,s2) == 1) {
if ((addr = inet_parse(s1,4)) != 0xffffffff &&
inet_valid_host(addr)) {
yylval.addr = addr;
return ADDR;
}
}
if (sscanf(q,"0x%8x%c",&n,s1) == 1) {
yylval.addr = n;
return ADDR;
}
if (sscanf(q,"%d%c",&n,s1) == 1) {
yylval.num = n;
return NUMBER;
}
#ifdef SNMP
if (*q=='"') {
if (q[ strlen(q)-1 ]=='"')
q[ strlen(q)-1 ]='\0'; /* trash trailing quote */
yylval.ptr = q+1;
return STRING;
}
#endif
yylval.ptr = q;
return STRING;
}
void
config_vifs_from_file()
{
order = 0;
state = 0;
numbounds = 0;
lineno = 0;
if ((f = fopen(configfilename, "r")) == NULL) {
if (errno != ENOENT)
log(LOG_ERR, errno, "can't open %s", configfilename);
return;
}
yyparse();
fclose(f);
}
static u_int32
valid_if(s)
char *s;
{
register vifi_t vifi;
register struct uvif *v;
for (vifi=0, v=uvifs; vifi<numvifs; vifi++, v++)
if (!strcmp(v->uv_name, s))
return v->uv_lcl_addr;
return 0;
}
static struct ifreq *
ifconfaddr(ifcp, a)
struct ifconf *ifcp;
u_int32 a;
{
int n;
struct ifreq *ifrp = (struct ifreq *)ifcp->ifc_buf;
struct ifreq *ifend = (struct ifreq *)((char *)ifrp + ifcp->ifc_len);
while (ifrp < ifend) {
if (ifrp->ifr_addr.sa_family == AF_INET &&
((struct sockaddr_in *)&ifrp->ifr_addr)->sin_addr.s_addr == a)
return (ifrp);
#ifdef HAVE_SA_LEN
n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
if (n < sizeof(*ifrp))
++ifrp;
else
ifrp = (struct ifreq *)((char *)ifrp + n);
#else
++ifrp;
#endif
}
return (0);
}