TEG_STATUS option_parse( int fd, char *str)
{
int i;
PARSER p;
DELIM igualador={ '=', ' ', ':' };
DELIM separador=DELIM_NULL;
p.igualador = &igualador;
p.separador = &separador;
p.data = str;
do {
if( (i=parser_call( &p )) ) {
if( option_lookup( fd,&p ) == TEG_STATUS_CONNCLOSED ) {
return TEG_STATUS_CONNCLOSED;
}
}
} while( i && p.hay_otro);
return TEG_STATUS_SUCCESS;
}
int main(int argc, char **argv) {
int ch, dhcp_payload_len;
unsigned char *dhcp_payload;
libnet_ptag_t ptag_dhcpv4, ptag_udp, ptag_ipv4, ptag_ethernet;
char *arg_secs, *arg_cip, *arg_chaddr, *arg_sip, *arg_ifname;
char *arg_operation, *arg_timeout, *arg_xid, *arg_flags, *arg_yip;
char *arg_gip, *arg_sname, *arg_fname, *arg_ether_dst, *stmp;
char *arg_ipv4_src, *arg_ipv4_dst, *arg_ipv4_tos, *arg_ipv4_ttl;
char *arg_reply_count;
if (argc < 2) usage("too few arguments");
srandom(time(NULL));
arg_secs = arg_cip = arg_chaddr = arg_sip = arg_ifname = NULL;
arg_operation = arg_timeout = arg_xid = arg_flags = arg_yip = NULL;
arg_gip = arg_sname = arg_fname = arg_ether_dst = arg_reply_count = NULL;
arg_ipv4_src = arg_ipv4_dst = arg_ipv4_tos = arg_ipv4_ttl = NULL;
verbosity = 1;
while ((ch = getopt(argc, argv, "s:c:h:i:o:t:x:f:y:g:S:A:B:O:X:v:F:T:L:Q:E:w:n:m")) != -1) {
switch (ch) {
case 's': arg_secs = optarg; break;
case 'c': arg_cip = optarg; break;
case 'h': arg_chaddr = optarg; break;
case 'S': arg_sip = optarg; break;
case 'i': arg_ifname = optarg; break;
case 'o': arg_operation = optarg; break;
case 't': arg_timeout = optarg; break;
case 'x': arg_xid = optarg; break;
case 'f': arg_flags = optarg; break;
case 'y': arg_yip = optarg; break;
case 'B': arg_fname = optarg; break;
case 'A': arg_sname = optarg; break;
case 'g': arg_gip = optarg; break;
case 'F': arg_ipv4_src = optarg; break;
case 'T': arg_ipv4_dst = optarg; break;
case 'L': arg_ipv4_ttl = optarg; break;
case 'Q': arg_ipv4_tos = optarg; break;
case 'n': arg_reply_count = optarg; break;
case 'E': arg_ether_dst = optarg; break;
case 'v': verbosity = atoi(optarg); break;
case 'm': no_double_options = 0; break;
case 'O': add_option(optarg); break;
case 'X': add_hexoption(optarg); break;
case 'w': option_lookup(optarg); break;
case '?':
default:
usage("unknown argument");
}
}
argc -= optind;
argv += optind;
/* Set some basic defaults */
set_defaults();
/* Make sure network interface was specified with -i option */
if (arg_ifname == NULL) {
usage("Error: network interface (-i option) not specified.");
}
strncpy(ifname, arg_ifname, 99);
/* Try to have pcap and libnet use the interface */
pcp = pcap_open_live(ifname, SNAPLEN, 1, 1, pcap_errbuf);
if (pcp == NULL) {
printf("pcap_open_live(%s) failed! Did you give the right interface name "
"and are you root?\n", ifname);
printf("pcap said: %s\n", pcap_errbuf);
exit(1);
}
lnp = libnet_init(LIBNET_LINK, ifname, libnet_errbuf);
if (lnp == NULL) {
printf("libnet_init(%s) failed!\n", ifname);
printf("libnet said: %s\n", libnet_errbuf);
exit(1);
}
/* Set chaddr MAC address */
if (arg_chaddr != NULL) {
int len = ETHER_ADDR_LEN;
/*chaddr = libnet_hex_aton((int8_t *)arg_chaddr, &len);*/
chaddr = libnet_hex_aton(arg_chaddr, &len);
if (chaddr == NULL) {
if (verbosity > 0)
printf("Invalid chaddr MAC address specified (%s)\n", arg_chaddr);
exit(1);
}
}
else {
/* Try to retrieve MAC address using libnet */
chaddr = (u_int8_t *)libnet_get_hwaddr(lnp);
if (chaddr == NULL) {
if (verbosity > 1) {
printf("Failed to retrieve MAC address for interface %s, using 0:0:0:0:0:0\n"
"Libnet said: %s\n", ifname, libnet_errbuf);
}
memset(chaddr, 0, ETHER_ADDR_LEN);
}
}
/* Set cip address */
if (arg_cip != NULL) {
cip = inet_addr(arg_cip);
if (cip == INADDR_NONE) {
if (verbosity > 0)
printf("Invalid cip address specified (%s)\n", arg_cip);
exit(1);
}
cip = ntohl(cip);
}
else {
/* Try to retrieve IP address using libnet */
cip = libnet_get_ipaddr4(lnp);
if ((int)cip == -1) {
if (verbosity > 1) {
printf("Failed to retrieve IPv4 address for interface %s, using cip 0.0.0.0\n"
"Libnet said: %s\n", ifname, libnet_errbuf);
}
cip = inet_addr("0.0.0.0");
}
else
cip = htonl(cip);
}
/**************************/
/* Set various parameters */
/**************************/
if (arg_operation != NULL) {
if (option_added(LIBNET_DHCP_MESSAGETYPE) && no_double_options) {
if (verbosity > 0) {
printf("Error: DHCP messagetype specified twice (don't use -o option if\n"
" you also intend to use -O to set option 53 (messagetype))\n");
}
exit(1);
}
if (strcasecmp(arg_operation, "discover") == 0) {
operation = LIBNET_DHCP_MSGDISCOVER;
if (arg_timeout == NULL)
timeout = 5;
}
else if (strcasecmp(arg_operation, "request") == 0) {
operation = LIBNET_DHCP_MSGREQUEST;
if (arg_timeout == NULL)
timeout = 5;
}
else if (strcasecmp(arg_operation, "inform") == 0) {
operation = LIBNET_DHCP_MSGINFORM;
if (timeout == 0)
timeout = 5;
}
else if (strcasecmp(arg_operation, "release") == 0)
operation = LIBNET_DHCP_MSGRELEASE;
else if (strcasecmp(arg_operation, "decline") == 0)
operation = LIBNET_DHCP_MSGDECLINE;
else {
if (verbosity > 0)
usage("Invalid DHCP operation type");
else
exit(1);
}
/* Add MESSAGETYPE DHCP option */
num_options++;
options = (struct dhcp_option *)
realloc(options, num_options * sizeof(struct dhcp_option));
options[num_options-1].opnum = LIBNET_DHCP_MESSAGETYPE;
options[num_options-1].oplen = 1;
options[num_options-1].opdata[0] = operation;
}
else {
/* no "-o operation" argument given */
if (option_added(LIBNET_DHCP_MESSAGETYPE) == 0) {
/* Add MESSAGETYPE DHCP option */
num_options++;
options = (struct dhcp_option *)
realloc(options, num_options * sizeof(struct dhcp_option));
options[num_options-1].opnum = LIBNET_DHCP_MESSAGETYPE;
options[num_options-1].oplen = 1;
options[num_options-1].opdata[0] = operation;
}
}
if (arg_secs != NULL) {
unsigned long ultmp;
ultmp = strtoul(arg_secs, &stmp, 0);
if (*stmp != '\0' || ultmp > 65535) {
if (verbosity > 0)
printf("Error: secs must be 0-65535 (was: %s)\n",
arg_secs);
exit(1);
}
secs = (u_int16_t)ultmp;
}
if (arg_timeout != NULL) {
timeout = strtoul(arg_timeout, &stmp, 0);
if (*stmp != '\0') {
if (verbosity > 0)
printf("Error: timeout value must be 0 or a positive integer (was: %s)\n",
arg_timeout);
exit(1);
}
}
if (arg_reply_count != NULL) {
reply_count = strtoul(arg_reply_count, &stmp, 0);
if (*stmp != '\0') {
if (verbosity > 0)
printf("Error: reply_count value must be 0 or a positive integer (was: %s)\n",
arg_reply_count);
exit(1);
}
}
if (arg_xid != NULL) {
xid = strtoul(arg_xid, &stmp, 0);
if (*stmp != '\0') {
if (verbosity > 0)
printf("Error: xid value must be 0 or a positive integer (was: %s)\n",
arg_xid);
exit(1);
}
}
if (arg_flags != NULL) {
unsigned long ultmp;
ultmp = strtoul(arg_flags, &stmp, 0);
if (*stmp != '\0' || ultmp > 65535) {
if (verbosity > 0)
printf("Error: flags value must be 0-65535 (was: %s)\n",
arg_flags);
exit(1);
}
flags = (u_int16_t)ultmp;
}
if (arg_sip != NULL) {
sip = inet_addr(arg_sip);
if (sip == INADDR_NONE) {
if (verbosity > 0)
printf("Error: specified sip value is not a valid IPv4 address (was: %s)\n",
arg_sip);
exit(1);
}
}
if (arg_yip != NULL) {
yip = inet_addr(arg_yip);
if (yip == INADDR_NONE) {
if (verbosity > 0)
printf("Error: specified yip value is not a valid IPv4 address (was: %s)\n",
arg_yip);
exit(1);
}
}
if (arg_gip != NULL) {
gip = inet_addr(arg_gip);
if (gip == INADDR_NONE) {
if (verbosity > 0)
printf("Error: specified gip value is not a valid IPv4 address (was: %s)\n",
arg_gip);
exit(1);
}
}
if (arg_fname != NULL) {
fname = (char *)malloc(strlen(fname)+1);
strcpy(fname, arg_fname);
}
if (arg_sname != NULL) {
sname = (char *)malloc(strlen(sname)+1);
strcpy(sname, arg_sname);
}
if (arg_ipv4_src != NULL) {
ipv4_src = inet_addr(arg_ipv4_src);
if (ipv4_src == INADDR_NONE) {
if (verbosity > 0)
printf("Error: specified ipv4_src value is not a valid IPv4 address (was: %s)\n",
arg_ipv4_src);
exit(1);
}
}
if (arg_ipv4_dst != NULL) {
ipv4_dst = inet_addr(arg_ipv4_dst);
if (ipv4_dst == INADDR_NONE) {
if (verbosity > 0)
printf("Error: specified ipv4_dst value is not a valid IPv4 address (was: %s)\n",
arg_ipv4_dst);
exit(1);
}
}
if (arg_ipv4_ttl != NULL) {
unsigned long ultmp;
ultmp = strtoul(arg_ipv4_ttl, &stmp, 0);
if (*stmp != '\0' || ultmp > 255) {
if (verbosity > 0)
printf("Error: ipv4_ttl value must be 0-255 (was: %s)\n",
arg_xid);
exit(1);
}
ipv4_ttl = (u_int8_t)ultmp;
}
if (arg_ipv4_tos != NULL) {
unsigned long ultmp;
ultmp = strtoul(arg_ipv4_tos, &stmp, 0);
if (*stmp != '\0' || ultmp > 255) {
if (verbosity > 0)
printf("Error: ipv4_tos value must be 0-255 (was: %s)\n",
arg_ipv4_tos);
exit(1);
}
ipv4_tos = (u_int8_t)ultmp;
}
if (arg_ether_dst != NULL) {
int l = ETHER_ADDR_LEN;
/*ether_dst = libnet_hex_aton((int8_t *)arg_ether_dst, &l);*/
ether_dst = libnet_hex_aton(arg_ether_dst, &l);
if (ether_dst == NULL) {
if (verbosity > 0)
printf("Error: invalid ethernet destination MAC specified (was: %s)\n",
arg_ether_dst);
exit(1);
}
}
/******************************
* Done setting parameters. *
* Start building DHCP packet *
******************************/
libnet_clear_packet(lnp);
/* Build DHCP payload (DHCP options section) */
dhcp_payload = build_payload(&dhcp_payload_len);
/* Create DHCP message */
ptag_dhcpv4 =
libnet_build_dhcpv4(LIBNET_DHCP_REQUEST,
BOOTP_HTYPE_ETHER,
ETHER_ADDR_LEN,
BOOTP_HOPCOUNT,
xid,
secs,
flags,
cip,
yip,
sip,
gip,
chaddr,
sname,
fname,
dhcp_payload,
dhcp_payload_len,
lnp,
0);
if (ptag_dhcpv4 == -1) {
printf("Failed to build bootp packet: %s\n", libnet_errbuf);
exit(1);
}
/*
libnet_ptag_t
libnet_build_udp(u_int16_t sp, u_int16_t dp, u_int16_t len, u_int16_t sum,
u_int8_t *payload, u_int32_t payload_s, libnet_t *l, libnet_ptag_t ptag);
*/
/* Create UDP datagram */
ptag_udp =
libnet_build_udp(UDP_SRCPORT,
UDP_DSTPORT,
dhcp_payload_len + LIBNET_DHCPV4_H + LIBNET_UDP_H,
0,
NULL,
0,
lnp,
0);
if (ptag_udp == -1) {
printf("Failed to build udp packet: %s\n", libnet_errbuf);
exit(1);
}
/*
libnet_ptag_t
libnet_build_ipv4(u_int16_t len, u_int8_t tos, u_int16_t id, u_int16_t frag,
u_int8_t ttl, u_int8_t prot, u_int16_t sum, u_int32_t src, u_int32_t dst,
u_int8_t *payload, u_int32_t payload_s, libnet_t *l, libnet_ptag_t ptag);
*/
/* Create IPv4 datagram */
ptag_ipv4 =
libnet_build_ipv4(dhcp_payload_len + LIBNET_DHCPV4_H + LIBNET_UDP_H + LIBNET_IPV4_H,
ipv4_tos,
ipv4_id++,
0,
ipv4_ttl,
IPPROTO_UDP,
0,
ipv4_src,
ipv4_dst,
NULL,
0,
lnp,
0);
if (ptag_ipv4 == -1) {
printf("Failed to build ipv4 packet: %s\n", libnet_errbuf);
exit(1);
}
/* Create ethernet packet */
ptag_ethernet =
libnet_autobuild_ethernet(ether_dst,
ETHERTYPE_IP,
lnp);
if (ptag_ethernet == -1) {
printf("Failed to build ethernet packet: %s\n", libnet_errbuf);
exit(1);
}
/* Write packet to network */
if (libnet_write(lnp) == -1) {
printf("Failed to write ethernet packet to network: %s\n", libnet_errbuf);
exit(1);
}
/* If we have to wait and listen for server replies, we use
a timer and a signal handler to quit. We do this as libpcap
doesn't support non-blocking packet capture on some (many?)
platforms. We could have launched another thread also, but
using timers and signals is simpler.
*/
if (timeout > 0) {
struct itimerval itv;
itv.it_interval.tv_sec = itv.it_value.tv_sec = timeout;
itv.it_interval.tv_usec = itv.it_value.tv_usec = 0;
setitimer(ITIMER_REAL, &itv, NULL);
signal(SIGALRM, sighandler);
pcap_loop(pcp, -1, pcap_callback, NULL);
}
libnet_destroy(lnp);
pcap_close(pcp);
exit(0);
}
/**
* Parse the arguments, looking for specific single-letter options. Whenever
* an option is found, the value in the option_t vector is set.
*
* Options start with a "-" and option parsing stops when "--" is encountered.
* Several argumentless options can be concatenated together after the initial
* "-". The value of the option can immediately follow the option letter,
* or be given by the next argument.
*
* Unrecognized options or missing arguments stop processing.
*
* @param argv the initial argument vector
* @param ovec the single-letter option description vector
* @param osize the amount of entries in ovec
*
* @return The number of options processed and validated, -1 on error.
*/
int
options_parse(const char *argv[], const option_t *ovec, int osize)
{
uchar options[127]; /* ASCII only */
const option_t *current;
int i;
g_assert(argv);
g_assert(osize >= 0);
g_assert(0 == osize || NULL != ovec);
/*
* Compile valid options.
*/
ZERO(&options);
error_string[0] = '\0';
for (i = 0; i < osize; i++) {
const option_t *o = &ovec[i];
uchar idx;
g_assert(o->letter);
idx = o->letter[0];
if (UNSIGNED(idx) >= N_ITEMS(options)) {
g_assert_not_reached();
return -1; /* ASCII only */
}
g_assert(!options[idx]); /* No duplicates */
options[idx] = OPTION_F_VALID;
if (o->letter[1] == ':')
options[idx] |= OPTION_F_VALUE;
if (o->value)
*o->value = NULL;
}
/*
* Analyze the arguments, starting at argv[1].
* (argv[0] is the command name).
*/
current = NULL;
for (i = 0; NULL != argv[i]; i++) {
const char *arg = argv[i];
uchar c;
if (0 == i)
continue;
if (0 == strcmp(arg, "--")) { /* End of options */
if (current) { /* This option lacks its argument */
str_bprintf(error_string, sizeof error_string,
"missing value for -%c", current->letter[0]);
return -1;
}
return i + 1;
}
if (current) {
/*
* We're expecting the next argument to be the value of the switch
* we parsed earlier.
*/
if (current->value)
*current->value = arg;
current = NULL;
continue;
}
if (*arg++ != '-') { /* Non-option found */
return i; /* First non-option argument */
}
/*
* Argument is an option, that can contain multiple argumentless
* switches, or a switch and its value.
*/
g_assert(current == NULL);
while ((c = *arg++)) {
const option_t *opt;
int flags;
if (UNSIGNED(c) >= N_ITEMS(options)) {
str_bprintf(error_string, sizeof error_string,
"invalid non-ASCII switch");
return -1;
}
flags = options[c];
if (!(flags & OPTION_F_VALID)) {
str_bprintf(error_string, sizeof error_string,
"invalid -%c switch", c);
return -1;
}
opt = option_lookup(c, ovec, osize);
g_assert(opt); /* Must have been found */
if (flags & OPTION_F_VALUE) { /* A value is expected */
if (*arg) { /* And it follows */
if (opt->value) {
*opt->value = arg;
}
break; /* Argument held option value */
} else
current = opt; /* Expecting value as next arg */
} else {
if (opt->value)
*opt->value = ""; /* Signals option was present */
}
}
}
return i;
}
