#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "parser.h"
enum token_type {
NOTOKEN,
ENDTOKEN,
KEYWORD,
PPP_ID,
ADDRESS,
INTERFACE,
PROTOCOL,
REALM,
USERNAME
};
struct token {
enum token_type type;
const char *keyword;
int value;
const struct token *next;
};
static struct parse_result res;
static const struct token t_main[];
static const struct token t_session[];
static const struct token t_clear[];
static const struct token t_monitor[];
static const struct token t_filter[];
static const struct token t_ppp_id[];
static const struct token t_address[];
static const struct token t_interface[];
static const struct token t_protocol[];
static const struct token t_realm[];
static const struct token t_username[];
static const struct token t_main[] = {
{ KEYWORD, "session", NONE, t_session },
{ KEYWORD, "clear", NONE, t_clear },
{ KEYWORD, "monitor", NONE, t_monitor },
{ ENDTOKEN, "", NONE, NULL }
};
static const struct token t_session[] = {
{ KEYWORD, "brief", SESSION_BRIEF, NULL },
{ KEYWORD, "packets", SESSION_PKTS, NULL },
{ KEYWORD, "all", SESSION_ALL, t_filter },
{ ENDTOKEN, "", NONE, NULL }
};
static const struct token t_clear[] = {
{ KEYWORD, "all", CLEAR_SESSION, NULL },
{ KEYWORD, "ppp-id", CLEAR_SESSION, t_ppp_id },
{ KEYWORD, "address", CLEAR_SESSION, t_address },
{ KEYWORD, "interface", CLEAR_SESSION, t_interface },
{ KEYWORD, "protocol", CLEAR_SESSION, t_protocol },
{ KEYWORD, "realm", CLEAR_SESSION, t_realm },
{ KEYWORD, "username", CLEAR_SESSION, t_username },
{ ENDTOKEN, "", CLEAR_SESSION, NULL }
};
static const struct token t_monitor[] = {
{ KEYWORD, "all", MONITOR_SESSION, NULL },
{ KEYWORD, "ppp-id", MONITOR_SESSION, t_ppp_id },
{ KEYWORD, "address", MONITOR_SESSION, t_address },
{ KEYWORD, "interface", MONITOR_SESSION, t_interface },
{ KEYWORD, "protocol", MONITOR_SESSION, t_protocol },
{ KEYWORD, "realm", MONITOR_SESSION, t_realm },
{ KEYWORD, "username", MONITOR_SESSION, t_username },
{ ENDTOKEN, "", MONITOR_SESSION, NULL }
};
static const struct token t_filter[] = {
{ NOTOKEN, "", NONE, NULL },
{ KEYWORD, "ppp-id", NONE, t_ppp_id },
{ KEYWORD, "address", NONE, t_address },
{ KEYWORD, "interface", NONE, t_interface },
{ KEYWORD, "protocol", NONE, t_protocol },
{ KEYWORD, "realm", NONE, t_realm },
{ KEYWORD, "username", NONE, t_username },
{ ENDTOKEN, "", NONE, NULL }
};
static const struct token t_ppp_id[] = {
{ PPP_ID, "", NONE, t_filter },
{ ENDTOKEN, "", NONE, NULL }
};
static const struct token t_address[] = {
{ ADDRESS, "", NONE, t_filter },
{ ENDTOKEN, "", NONE, NULL }
};
static const struct token t_interface[] = {
{ INTERFACE, "", NONE, t_filter },
{ ENDTOKEN, "", NONE, NULL }
};
static const struct token t_protocol[] = {
{ PROTOCOL, "", NONE, t_filter },
{ ENDTOKEN, "", NONE, NULL }
};
static const struct token t_realm[] = {
{ REALM, "", NONE, t_filter },
{ ENDTOKEN, "", NONE, NULL }
};
static const struct token t_username[] = {
{ USERNAME, "", NONE, t_filter },
{ ENDTOKEN, "", NONE, NULL }
};
static const struct token *match_token(char *, const struct token []);
static void show_valid_args(const struct token []);
struct parse_result *
parse(int argc, char *argv[])
{
const struct token *table = t_main;
const struct token *match;
bzero(&res, sizeof(res));
while (argc >= 0) {
if ((match = match_token(argv[0], table)) == NULL) {
fprintf(stderr, "valid commands/args:\n");
show_valid_args(table);
return (NULL);
}
argc--;
argv++;
if (match->type == NOTOKEN || match->next == NULL)
break;
table = match->next;
}
if (argc > 0) {
fprintf(stderr, "superfluous argument: %s\n", argv[0]);
return (NULL);
}
return (&res);
}
static const struct token *
match_token(char *word, const struct token table[])
{
u_int i, match = 0;
unsigned long int ulval;
const struct token *t = NULL;
char *ep;
for (i = 0; table[i].type != ENDTOKEN; i++) {
switch (table[i].type) {
case NOTOKEN:
if (word == NULL || strlen(word) == 0) {
match++;
t = &table[i];
}
break;
case KEYWORD:
if (word != NULL && strncmp(word, table[i].keyword,
strlen(word)) == 0) {
match++;
t = &table[i];
if (t->value)
res.action = t->value;
}
break;
case PPP_ID:
if (word == NULL)
break;
errno = 0;
ulval = strtoul(word, &ep, 10);
if (isdigit((unsigned char)*word) && *ep == '\0' &&
!(errno == ERANGE && ulval == ULONG_MAX)) {
res.ppp_id = ulval;
res.has_ppp_id = 1;
match++;
t = &table[i];
}
break;
case ADDRESS:
{
struct sockaddr_in sin4 = {
.sin_family = AF_INET,
.sin_len = sizeof(struct sockaddr_in)
};
struct sockaddr_in6 sin6 = {
.sin6_family = AF_INET6,
.sin6_len = sizeof(struct sockaddr_in6)
};
if (word == NULL)
break;
if (inet_pton(AF_INET, word, &sin4.sin_addr) == 1)
memcpy(&res.address, &sin4, sin4.sin_len);
else
if (inet_pton(AF_INET6, word, &sin6.sin6_addr) == 1)
memcpy(&res.address, &sin6, sin6.sin6_len);
else
break;
match++;
t = &table[i];
}
break;
case INTERFACE:
if (word == NULL)
break;
res.interface = word;
match++;
t = &table[i];
break;
case PROTOCOL:
if (word == NULL)
break;
if ((res.protocol = parse_protocol(word)) ==
PROTO_UNSPEC)
break;
match++;
t = &table[i];
break;
case REALM:
if (word == NULL)
break;
res.realm = word;
match++;
t = &table[i];
break;
case USERNAME:
if (word == NULL)
break;
res.username = word;
match++;
t = &table[i];
break;
case ENDTOKEN:
break;
}
}
if (match != 1) {
if (word == NULL)
fprintf(stderr, "missing argument:\n");
else if (match > 1)
fprintf(stderr, "ambiguous argument: %s\n", word);
else if (match < 1)
fprintf(stderr, "unknown argument: %s\n", word);
return (NULL);
}
return (t);
}
static void
show_valid_args(const struct token table[])
{
int i;
for (i = 0; table[i].type != ENDTOKEN; i++) {
switch (table[i].type) {
case NOTOKEN:
fprintf(stderr, " <cr>\n");
break;
case KEYWORD:
fprintf(stderr, " %s\n", table[i].keyword);
break;
case PPP_ID:
fprintf(stderr, " <ppp-id>\n");
break;
case ADDRESS:
fprintf(stderr, " <address>\n");
break;
case INTERFACE:
fprintf(stderr, " <interface>\n");
break;
case PROTOCOL:
fprintf(stderr, " [ pppoe | l2tp | pptp | sstp ]\n");
break;
case REALM:
fprintf(stderr, " <realm>\n");
break;
case USERNAME:
fprintf(stderr, " <username>\n");
break;
case ENDTOKEN:
break;
}
}
}
enum protocol
parse_protocol(const char *str)
{
return
(strcasecmp(str, "PPTP" ) == 0)? PPTP :
(strcasecmp(str, "L2TP" ) == 0)? L2TP :
(strcasecmp(str, "PPPoE") == 0)? PPPOE :
(strcasecmp(str, "SSTP" ) == 0)? SSTP : PROTO_UNSPEC;
}
