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#include "ipf.h"
#include <ctype.h>
typedef struct ipfopentry {
int ipoe_cmd;
int ipoe_nbasearg;
int ipoe_maxarg;
int ipoe_argsize;
char *ipoe_word;
} ipfopentry_t;
static ipfopentry_t opwords[17] = {
{ IPF_EXP_IP_ADDR, 2, 0, 1, "ip.addr" },
{ IPF_EXP_IP6_ADDR, 2, 0, 4, "ip6.addr" },
{ IPF_EXP_IP_PR, 1, 0, 1, "ip.p" },
{ IPF_EXP_IP_SRCADDR, 2, 0, 1, "ip.src" },
{ IPF_EXP_IP_DSTADDR, 2, 0, 1, "ip.dst" },
{ IPF_EXP_IP6_SRCADDR, 2, 0, 4, "ip6.src" },
{ IPF_EXP_IP6_DSTADDR, 2, 0, 4, "ip6.dst" },
{ IPF_EXP_TCP_PORT, 1, 0, 1, "tcp.port" },
{ IPF_EXP_TCP_DPORT, 1, 0, 1, "tcp.dport" },
{ IPF_EXP_TCP_SPORT, 1, 0, 1, "tcp.sport" },
{ IPF_EXP_TCP_FLAGS, 2, 0, 1, "tcp.flags" },
{ IPF_EXP_UDP_PORT, 1, 0, 1, "udp.port" },
{ IPF_EXP_UDP_DPORT, 1, 0, 1, "udp.dport" },
{ IPF_EXP_UDP_SPORT, 1, 0, 1, "udp.sport" },
{ IPF_EXP_TCP_STATE, 1, 0, 1, "tcp.state" },
{ IPF_EXP_IDLE_GT, 1, 1, 1, "idle-gt" },
{ -1, 0, 0, 0, NULL }
};
int *
parseipfexpr(line, errorptr)
char *line;
char **errorptr;
{
int not, items, asize, *oplist, osize, i;
char *temp, *arg, *s, *t, *ops, *error;
ipfopentry_t *e;
ipfexp_t *ipfe;
asize = 0;
error = NULL;
oplist = NULL;
temp = strdup(line);
if (temp == NULL) {
error = "strdup failed";
goto parseerror;
}
/*
* Eliminate any white spaces to make parsing easier.
*/
for (s = temp; *s != '\0'; ) {
if (ISSPACE(*s))
strcpy(s, s + 1);
else
s++;
}
/*
* Parse the string.
* It should be sets of "ip.dst=1.2.3.4/32;" things.
* There must be a "=" or "!=" and it must end in ";".
*/
if (temp[strlen(temp) - 1] != ';') {
error = "last character not ';'";
goto parseerror;
}
/*
* Work through the list of complete operands present.
*/
for (ops = strtok(temp, ";"); ops != NULL; ops = strtok(NULL, ";")) {
arg = strchr(ops, '=');
if ((arg < ops + 2) || (arg == NULL)) {
error = "bad 'arg' vlaue";
goto parseerror;
}
if (*(arg - 1) == '!') {
*(arg - 1) = '\0';
not = 1;
} else {
not = 0;
}
*arg++ = '\0';
for (e = opwords; e->ipoe_word; e++) {
if (strcmp(ops, e->ipoe_word) == 0)
break;
}
if (e->ipoe_word == NULL) {
error = malloc(32);
if (error != NULL) {
sprintf(error, "keyword (%.10s) not found",
ops);
}
goto parseerror;
}
/*
* Count the number of commas so we know how big to
* build the array
*/
for (s = arg, items = 1; *s != '\0'; s++)
if (*s == ',')
items++;
if ((e->ipoe_maxarg != 0) && (items > e->ipoe_maxarg)) {
error = "too many items";
goto parseerror;
}
/*
* osize will mark the end of where we have filled up to
* and is thus where we start putting new data.
*/
osize = asize;
asize += 4 + (items * e->ipoe_nbasearg * e->ipoe_argsize);
if (oplist == NULL)
oplist = calloc(1, sizeof(int) * (asize + 2));
else
oplist = realloc(oplist, sizeof(int) * (asize + 2));
if (oplist == NULL) {
error = "oplist alloc failed";
goto parseerror;
}
ipfe = (ipfexp_t *)(oplist + osize);
osize += 4;
ipfe->ipfe_cmd = e->ipoe_cmd;
ipfe->ipfe_not = not;
ipfe->ipfe_narg = items * e->ipoe_nbasearg;
ipfe->ipfe_size = items * e->ipoe_nbasearg * e->ipoe_argsize;
ipfe->ipfe_size += 4;
for (s = arg; (*s != '\0') && (osize < asize); s = t) {
/*
* Look for the end of this arg or the ',' to say
* there is another following.
*/
for (t = s; (*t != '\0') && (*t != ','); t++)
;
if (*t == ',')
*t++ = '\0';
if (!strcasecmp(ops, "ip.addr") ||
!strcasecmp(ops, "ip.src") ||
!strcasecmp(ops, "ip.dst")) {
i6addr_t mask, addr;
char *delim;
delim = strchr(s, '/');
if (delim != NULL) {
*delim++ = '\0';
if (genmask(AF_INET, delim,
&mask) == -1) {
error = "genmask failed";
goto parseerror;
}
} else {
mask.in4.s_addr = 0xffffffff;
}
if (gethost(AF_INET, s, &addr) == -1) {
error = "gethost failed";
goto parseerror;
}
oplist[osize++] = addr.in4.s_addr;
oplist[osize++] = mask.in4.s_addr;
#ifdef USE_INET6
} else if (!strcasecmp(ops, "ip6.addr") ||
!strcasecmp(ops, "ip6.src") ||
!strcasecmp(ops, "ip6.dst")) {
i6addr_t mask, addr;
char *delim;
delim = strchr(s, '/');
if (delim != NULL) {
*delim++ = '\0';
if (genmask(AF_INET6, delim,
&mask) == -1) {
error = "genmask failed";
goto parseerror;
}
} else {
mask.i6[0] = 0xffffffff;
mask.i6[1] = 0xffffffff;
mask.i6[2] = 0xffffffff;
mask.i6[3] = 0xffffffff;
}
if (gethost(AF_INET6, s, &addr) == -1) {
error = "gethost failed";
goto parseerror;
}
oplist[osize++] = addr.i6[0];
oplist[osize++] = addr.i6[1];
oplist[osize++] = addr.i6[2];
oplist[osize++] = addr.i6[3];
oplist[osize++] = mask.i6[0];
oplist[osize++] = mask.i6[1];
oplist[osize++] = mask.i6[2];
oplist[osize++] = mask.i6[3];
#endif
} else if (!strcasecmp(ops, "ip.p")) {
int p;
p = getproto(s);
if (p == -1)
goto parseerror;
oplist[osize++] = p;
} else if (!strcasecmp(ops, "tcp.flags")) {
u_32_t mask, flags;
char *delim;
delim = strchr(s, '/');
if (delim != NULL) {
*delim++ = '\0';
mask = tcpflags(delim);
} else {
mask = 0xff;
}
flags = tcpflags(s);
oplist[osize++] = flags;
oplist[osize++] = mask;
} else if (!strcasecmp(ops, "tcp.port") ||
!strcasecmp(ops, "tcp.sport") ||
!strcasecmp(ops, "tcp.dport") ||
!strcasecmp(ops, "udp.port") ||
!strcasecmp(ops, "udp.sport") ||
!strcasecmp(ops, "udp.dport")) {
char proto[4];
u_short port;
strncpy(proto, ops, 3);
proto[3] = '\0';
if (getport(NULL, s, &port, proto) == -1)
goto parseerror;
oplist[osize++] = port;
} else if (!strcasecmp(ops, "tcp.state")) {
oplist[osize++] = atoi(s);
} else {
error = "unknown word";
goto parseerror;
}
}
}
free(temp);
if (errorptr != NULL)
*errorptr = NULL;
for (i = asize; i > 0; i--)
oplist[i] = oplist[i - 1];
oplist[0] = asize + 2;
oplist[asize + 1] = IPF_EXP_END;
return oplist;
parseerror:
if (errorptr != NULL)
*errorptr = error;
if (oplist != NULL)
free(oplist);
if (temp != NULL)
free(temp);
return NULL;
}
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