/* Copyright (C) 2000,2001 Salvatore Sanfilippo <antirez@invece.org>
* See the LICENSE file for more information.
*
* ARS Packet Description System.
*
* Please, prefix all the function with ars_d_ */
/* $Id: apd.c,v 1.3 2003/09/07 11:21:18 antirez Exp $ */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <ctype.h>
#include "ars.h"
#include "hstring.h"
#include "hex.h"
/* FIXME: parsing should use dynamic buffers to use less memory.
* For now we support MTU up to 3000 */
#define ARS_MAX_TSIZE (3000*4)
char *ars_d_parser(char *t, char *next, size_t size)
{
int i = 0;
if (size == 0 || next == NULL || *t == '\0')
return NULL;
size--; /* space for nul term */
while (1) {
/* no space for the next char */
if (i == size) {
next[i] = '\0';
return t;
}
switch(*t) {
case '\0':
case '(':
case ')':
case ',':
case '=':
case '+':
if (i == 0) {
next[i] = *t;
next[i+1] = '\0';
return t+1;
} else {
next[i] = '\0';
return t;
}
default:
next[i++] = *t++;
break;
}
}
return NULL; /* unreached */
}
/* states */
#define ARS_G_LAYER 0
#define ARS_G_FIELD_OR_CBRACE 1
#define ARS_G_VALUE 2
#define ARS_G_OBRACE_OR_PLUS 3
#define ARS_G_CBRACE 4
#define ARS_G_COMMA_OR_CBRACE 5
#define ARS_G_LEN_OR_PLUS 6
#define ARS_G_PLUS 7
#define ARS_G_EQUAL 8
struct ars_d_keyword_info {
char *ki_keyword;
int ki_opt;
void *(*ki_add) (struct ars_packet *pkt, int opt);
int (*ki_set) (struct ars_packet *pkt, int layer, char *f, char *v);
};
#define ARS_DKINFO_SIZE 64
/* If the user specify a layer number of -1 with *set functions, the
* last layer is selected */
#define ARS_DEF_LAYER \
do { \
if (layer == ARS_LAST_LAYER) \
layer = pkt->p_layer_nr - 1; \
if (ars_valid_layer(layer) != -ARS_OK) \
return -ARS_INVALID; \
} while(0)
#define BOGUS_SET_F(x) \
int (x)(struct ars_packet *pkt, int layer, char *f, char *v) { return 0; }
int ars_d_set_ip(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_udp(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_tcp(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_icmp(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_data(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_ipopt_rr(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_ipopt_ts(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_ipopt_sid(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_ipopt_sec(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_ipopt_dumb(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_tcpopt_mss(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_tcpopt_wscale(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_tcpopt_sack(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_tcpopt_echo(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_tcpopt_dumb(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_igrp(struct ars_packet *pkt, int layer, char *f, char *v);
int ars_d_set_igrpentry(struct ars_packet *pkt, int layer, char *f, char *v);
BOGUS_SET_F(ars_d_set_tcpopt_ts)
struct ars_d_keyword_info ars_dkinfo[ARS_DKINFO_SIZE] = {
/* KEYWORD OPT ADD function SET function *
* --------------------------------------------------------- */
{"ip", 0, ars_add_iphdr, ars_d_set_ip},
{"ip.eol", ARS_IPOPT_EOL, ars_add_ipopt, ars_d_set_ipopt_dumb},
{"ip.nop", ARS_IPOPT_NOP, ars_add_ipopt, ars_d_set_ipopt_dumb},
{"ip.sec", ARS_IPOPT_SEC, ars_add_ipopt, ars_d_set_ipopt_sec},
{"ip.sid", ARS_IPOPT_SID, ars_add_ipopt, ars_d_set_ipopt_sid},
{"ip.lsrr", ARS_IPOPT_LSRR, ars_add_ipopt, ars_d_set_ipopt_rr},
{"ip.ssrr", ARS_IPOPT_SSRR, ars_add_ipopt, ars_d_set_ipopt_rr},
{"ip.rr", ARS_IPOPT_RR, ars_add_ipopt, ars_d_set_ipopt_rr},
{"ip.ts", ARS_IPOPT_TIMESTAMP, ars_add_ipopt, ars_d_set_ipopt_ts},
{"udp", 0, ars_add_udphdr, ars_d_set_udp},
{"tcp", 0, ars_add_tcphdr, ars_d_set_tcp},
{"tcp.eol", ARS_TCPOPT_EOL, ars_add_tcpopt, ars_d_set_tcpopt_dumb},
{"tcp.nop", ARS_TCPOPT_NOP, ars_add_tcpopt, ars_d_set_tcpopt_dumb},
{"tcp.mss", ARS_TCPOPT_MAXSEG, ars_add_tcpopt, ars_d_set_tcpopt_mss},
{"tcp.wscale", ARS_TCPOPT_WINDOW, ars_add_tcpopt, ars_d_set_tcpopt_wscale},
{"tcp.sackperm", ARS_TCPOPT_SACK_PERM, ars_add_tcpopt, ars_d_set_tcpopt_dumb},
{"tcp.sack", ARS_TCPOPT_SACK, ars_add_tcpopt, ars_d_set_tcpopt_sack},
{"tcp.echo", ARS_TCPOPT_ECHOREQUEST, ars_add_tcpopt, ars_d_set_tcpopt_echo},
{"tcp.echoreply", ARS_TCPOPT_ECHOREPLY, ars_add_tcpopt, ars_d_set_tcpopt_echo},
{"tcp.ts", ARS_TCPOPT_TIMESTAMP, ars_add_tcpopt, ars_d_set_tcpopt_ts},
{"icmp", 0, ars_add_icmphdr, ars_d_set_icmp},
{"igrp", 0, ars_add_igrphdr, ars_d_set_igrp},
{"igrp.entry", 0, ars_add_igrpentry, ars_d_set_igrpentry},
{"data", 0, ars_add_data, ars_d_set_data},
{NULL, 0, NULL, NULL} /* nul term */
};
struct ars_d_keyword_info *ars_get_keyword_by_name(char *name)
{
struct ars_d_keyword_info *k = ars_dkinfo;
while (k->ki_keyword) {
if (strcasecmp(k->ki_keyword, name) == 0)
return k;
k++;
}
return NULL;
}
int ars_d_setlayer_size(struct ars_packet *pkt, int layer, char *size)
{
size_t newsize;
ARS_DEF_LAYER;
newsize = ars_atou(size);
if (newsize < 1 || newsize > pkt->p_layer[layer].l_size) {
ars_set_error(pkt, "Invalid layer size in description");
return -ARS_INVALID;
}
pkt->p_layer[layer].l_size = newsize;
__D(printf("Setting the layer to size %s\n", size);)
return -ARS_OK;
}
int ars_d_set_ip(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_iphdr *ip;
ARS_DEF_LAYER;
ip = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "saddr") == 0) {
return ars_resolve(pkt, &ip->saddr, v);
} else if (strcasecmp(f, "daddr") == 0) {
return ars_resolve(pkt, &ip->daddr, v);
} else if (strcasecmp(f, "ihl") == 0) {
ip->ihl = ars_atou(v);
pkt->p_layer[layer].l_flags |= ARS_TAKE_IP_HDRLEN;
} else if (strcasecmp(f, "ver") == 0) {
ip->version = ars_atou(v);
pkt->p_layer[layer].l_flags |= ARS_TAKE_IP_VERSION;
} else if (strcasecmp(f, "tos") == 0) {
ip->tos = ars_atou(v);
} else if (strcasecmp(f, "totlen") == 0) {
ip->tot_len = htons(ars_atou(v));
pkt->p_layer[layer].l_flags |= ARS_TAKE_IP_TOTLEN;
} else if (strcasecmp(f, "id") == 0) {
ip->id = htons(ars_atou(v));
} else if (strcasecmp(f, "fragoff") == 0) {
ip->frag_off = ip->frag_off & 0xE000;
ip->frag_off |= htons(ars_atou(v) >> 3);
} else if (strcasecmp(f, "mf") == 0) {
if (ars_atou(v) == 0)
ip->frag_off &= htons(~ARS_IP_MF);
else
ip->frag_off |= htons(ARS_IP_MF);
} else if (strcasecmp(f, "df") == 0) {
if (ars_atou(v) == 0)
ip->frag_off &= htons(~ARS_IP_DF);
else
ip->frag_off |= htons(ARS_IP_DF);
} else if (strcasecmp(f, "rf") == 0) {
if (ars_atou(v) == 0)
ip->frag_off &= htons((u_int16_t)~ARS_IP_RF);
else
ip->frag_off |= htons(ARS_IP_RF);
} else if (strcasecmp(f, "ttl") == 0) {
ip->ttl = ars_atou(v);
} else if (strcasecmp(f, "proto") == 0) {
if (!strcasecmp(v, "icmp")) {
ip->protocol = ARS_IPPROTO_ICMP;
} else if (!strcasecmp(v, "udp")) {
ip->protocol = ARS_IPPROTO_UDP;
} else if (!strcasecmp(v, "tcp")) {
ip->protocol = ARS_IPPROTO_TCP;
} else {
ip->protocol = ars_atou(v);
}
pkt->p_layer[layer].l_flags |= ARS_TAKE_IP_PROTOCOL;
} else if (strcasecmp(f, "cksum") == 0) {
ip->check = htons(ars_atou(v));
pkt->p_layer[layer].l_flags |= ARS_TAKE_IP_CKSUM;
} else {
ars_set_error(pkt, "Invalid field for IP layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
/* Note: for all the variable-length ip options the allocated layer data
* length is always as big as possible (40 bytes), so set_ipopt_rr() and
* other similar functions don't need to check if there is enough room.
* Of course functions shoult still check to not overflow over the 40
* bytes, but this makes very little sense. */
#define IPOPTRR_MAX_ENTRIES 9
int ars_d_set_ipopt_rr(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_ipopt *ipopt;
ARS_DEF_LAYER;
ipopt = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "optlen") == 0) {
ipopt->len = ars_atou(v);
} else if (strcasecmp(f, "ptr") == 0) {
ipopt->un.rr.ptr = ars_atou(v);
pkt->p_layer[layer].l_flags |= ARS_TAKE_IPOPT_PTR;
} else if (strcasecmp(f, "data") == 0) {
char *addrv[IPOPTRR_MAX_ENTRIES];
int vlen = strlen(v), num, i;
char *vcopy = alloca(vlen+1);
unsigned char *data = pkt->p_layer[layer].l_data;
memcpy(vcopy, v, vlen+1);
num = strftok("/", vcopy, addrv, IPOPTRR_MAX_ENTRIES);
for (i = 0; i < num; i++) {
__u32 addr;
int err;
err = ars_resolve(pkt, &addr, addrv[i]);
if (err != -ARS_OK)
return err;
memcpy(data+3+(i*4), &addr, 4);
}
if (ARS_DONTTAKE(pkt->p_layer[layer].l_flags,
ARS_TAKE_IPOPT_PTR))
{
/* For the record route option the default ptr
* is at the end of the specified entries */
if (ipopt->kind == ARS_IPOPT_RR) {
ipopt->un.rr.ptr = 4+(num*4);
} else {
/* For SSRR and LSRR is set at the start
* if not otherwise specified. */
ipopt->un.rr.ptr = 4;
}
}
} else {
ars_set_error(pkt, "Invalid field for IP.RR layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
#define IPOPTTS_MAX_ENTRIES 9
int ars_d_set_ipopt_ts(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_ipopt *ipopt;
int flags, overflow;
ARS_DEF_LAYER;
ipopt = pkt->p_layer[layer].l_data;
overflow = (ipopt->un.ts.flags & 0xF0) >> 4;
flags = ipopt->un.ts.flags & 0xF;
if (strcasecmp(f, "optlen") == 0) {
ipopt->len = ars_atou(v);
} else if (strcasecmp(f, "ptr") == 0) {
ipopt->un.rr.ptr = ars_atou(v);
pkt->p_layer[layer].l_flags |= ARS_TAKE_IPOPT_PTR;
} else if (strcasecmp(f, "flags") == 0) {
if (strisnum(v)) {
flags = ars_atou(v) & 0xF;
} else {
if (!strcasecmp(v, "tsonly"))
flags = ARS_IPOPT_TS_TSONLY;
else if (!strcasecmp(v, "tsandaddr"))
flags = ARS_IPOPT_TS_TSANDADDR;
else if (!strcasecmp(v, "prespec"))
flags = ARS_IPOPT_TS_PRESPEC;
else {
ars_set_error(pkt, "Invalid symbol for ip.ts flags: '%s' (use: tsonly, tsandaddr, prespec or a numerical value)", v);
return -ARS_INVALID;
}
}
ipopt->un.ts.flags = ((overflow&0xF)<<4)|(flags&0xF);
} else if (strcasecmp(f, "overflow") == 0) {
overflow = ars_atou(v) & 0xF;
ipopt->un.ts.flags = ((overflow&0xF)<<4)|(flags&0xF);
} else if (strcasecmp(f, "data") == 0) {
char *addrv[IPOPTTS_MAX_ENTRIES];
int vlen = strlen(v), num, i;
char *vcopy = alloca(vlen+1);
unsigned char *data = pkt->p_layer[layer].l_data;
memcpy(vcopy, v, vlen+1);
num = strftok("/", vcopy, addrv, IPOPTTS_MAX_ENTRIES);
for (i = 0; i < num; i++) {
__u32 addr, ts;
int err;
char *p;
p = strchr(addrv[i], '@');
if (p) {
if (flags == ARS_IPOPT_TS_TSONLY) {
ars_set_error(pkt, "Gateway specified but ip.ts flags set to 'tsonly'. (Try flags=tsandaddr,data=...)");
return -ARS_INVALID;
}
*p = '\0';
p++;
err = ars_resolve(pkt, &addr, p);
if (err != -ARS_OK)
return err;
ts = ars_atou(addrv[i]);
ts = htonl(ts);
if (i < 4) {
memcpy(data+4+(i*8), &addr, 4);
memcpy(data+8+(i*8), &ts, 4);
};
} else {
if (flags == ARS_IPOPT_TS_TSANDADDR ||
flags == ARS_IPOPT_TS_PRESPEC) {
ars_set_error(pkt, "Gateway not specified in data for ip.ts, but flags set to 'tsandaddr' or 'prespec'. (Try flags=tsonly)");
return -ARS_INVALID;
}
ts = ars_atou(addrv[i]);
ts = htonl(ts);
memcpy(data+4+(i*4), &ts, 4);
}
}
if (ARS_DONTTAKE(pkt->p_layer[layer].l_flags,
ARS_TAKE_IPOPT_PTR))
{
if (flags == ARS_IPOPT_TS_TSANDADDR ||
flags == ARS_IPOPT_TS_PRESPEC) {
ipopt->un.rr.ptr = 5+(num*8);
} else {
ipopt->un.rr.ptr = 5+(num*4);
}
}
} else {
ars_set_error(pkt, "Invalid field for IP.TS layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_ipopt_sid(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_ipopt *ipopt;
ARS_DEF_LAYER;
ipopt = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "optlen") == 0) {
ipopt->len = ars_atou(v);
} else if (strcasecmp(f, "sid") == 0) {
ipopt->un.sid.id = ars_atou(v);
} else {
ars_set_error(pkt, "Invalid field for IP.SID layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_ipopt_sec(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_ipopt *ipopt;
ARS_DEF_LAYER;
ipopt = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "optlen") == 0) {
ipopt->len = ars_atou(v);
} else if (strcasecmp(f, "seclev") == 0) {
ipopt->un.sec.s = ars_atou(v);
} else if (strcasecmp(f, "comp") == 0) {
ipopt->un.sec.c = ars_atou(v);
} else if (strcasecmp(f, "hrest") == 0) {
if (strlen(v) != 4) {
ars_set_error(pkt, "Invalid ip.sec hrest field value of '%s'(should be four hex digits, like this: ...,hrest=252A,...)", v);
return -ARS_INVALID;
}
if (hextobin(&ipopt->un.sec.h, v, 4)) {
ars_set_error(pkt, "Invalid hex value for ip.sec hex: '%s'", v);
return -ARS_INVALID;
}
} else if (strcasecmp(f, "tcc") == 0) {
if (strlen(v) != 6) {
ars_set_error(pkt, "Invalid ip.sec tcc field value of '%s'(should be six hex digits, like this: ...,tcc=252A27,...)", v);
return -ARS_INVALID;
}
if (hextobin(&ipopt->un.sec.h, v, 6)) {
ars_set_error(pkt, "Invalid hex value for ip.sec hex: '%s'", v);
return -ARS_INVALID;
}
} else {
ars_set_error(pkt, "Invalid field for IP.SEC layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_ipopt_dumb(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_ipopt *ipopt;
ARS_DEF_LAYER;
ipopt = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "optlen") == 0) {
ipopt->len = ars_atou(v);
} else {
ars_set_error(pkt, "Invalid field for IP.? layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_udp(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_udphdr *udp;
ARS_DEF_LAYER;
udp = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "sport") == 0) {
udp->uh_sport = htons(ars_atou(v));
} else if (strcasecmp(f, "dport") == 0) {
udp->uh_dport = htons(ars_atou(v));
} else if (strcasecmp(f, "len") == 0) {
udp->uh_ulen = htons(ars_atou(v));
pkt->p_layer[layer].l_flags |= ARS_TAKE_UDP_LEN;
} else if (strcasecmp(f, "cksum") == 0) {
udp->uh_sum = htons(ars_atou(v));
pkt->p_layer[layer].l_flags |= ARS_TAKE_UDP_CKSUM;
} else {
ars_set_error(pkt, "Invalid field for UDP layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_tcp(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_tcphdr *tcp;
ARS_DEF_LAYER;
tcp = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "sport") == 0) {
tcp->th_sport = htons(ars_atou(v));
} else if (strcasecmp(f, "dport") == 0) {
tcp->th_dport = htons(ars_atou(v));
} else if (strcasecmp(f, "seq") == 0) {
tcp->th_seq = htonl(ars_atou(v));
} else if (strcasecmp(f, "ack") == 0) {
tcp->th_ack = htonl(ars_atou(v));
} else if (strcasecmp(f, "x2") == 0) {
tcp->th_x2 = ars_atou(v);
} else if (strcasecmp(f, "off") == 0) {
tcp->th_off = ars_atou(v);
pkt->p_layer[layer].l_flags |= ARS_TAKE_TCP_HDRLEN;
} else if (strcasecmp(f, "flags") == 0) {
tcp->th_flags = 0;
if (strchr(v, 'f') || strchr(v, 'F'))
tcp->th_flags |= ARS_TCP_TH_FIN;
if (strchr(v, 's') || strchr(v, 'S'))
tcp->th_flags |= ARS_TCP_TH_SYN;
if (strchr(v, 'r') || strchr(v, 'R'))
tcp->th_flags |= ARS_TCP_TH_RST;
if (strchr(v, 'p') || strchr(v, 'P'))
tcp->th_flags |= ARS_TCP_TH_PUSH;
if (strchr(v, 'a') || strchr(v, 'A'))
tcp->th_flags |= ARS_TCP_TH_ACK;
if (strchr(v, 'u') || strchr(v, 'U'))
tcp->th_flags |= ARS_TCP_TH_URG;
if (strchr(v, 'x') || strchr(v, 'X'))
tcp->th_flags |= ARS_TCP_TH_X;
if (strchr(v, 'y') || strchr(v, 'Y'))
tcp->th_flags |= ARS_TCP_TH_Y;
} else if (strcasecmp(f, "win") == 0) {
tcp->th_win = htons(ars_atou(v));
} else if (strcasecmp(f, "cksum") == 0) {
tcp->th_sum = htons(ars_atou(v));
pkt->p_layer[layer].l_flags |= ARS_TAKE_TCP_CKSUM;
} else if (strcasecmp(f, "urp") == 0) {
tcp->th_urp = htons(ars_atou(v));
} else {
ars_set_error(pkt, "Invalid field for TCP layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_tcpopt_mss(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_tcpopt *tcpopt;
ARS_DEF_LAYER;
tcpopt = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "optlen") == 0) {
tcpopt->len = ars_atou(v);
} else if (strcasecmp(f, "size") == 0) {
tcpopt->un.mss.size = htons(ars_atou(v));
} else {
ars_set_error(pkt, "Invalid field for TCP.MSS layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_tcpopt_wscale(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_tcpopt *tcpopt;
ARS_DEF_LAYER;
tcpopt = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "optlen") == 0) {
tcpopt->len = ars_atou(v);
} else if (strcasecmp(f, "shift") == 0) {
tcpopt->un.win.shift = htons(ars_atou(v));
} else {
ars_set_error(pkt, "Invalid field for TCP.WSCALE layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
#define TCPOPTSACK_MAX_ENTRIES 4
int ars_d_set_tcpopt_sack(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_tcpopt *tcpopt;
ARS_DEF_LAYER;
tcpopt = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "optlen") == 0) {
tcpopt->len = ars_atou(v);
} else if (strcasecmp(f, "blocks") == 0) {
char *bv[TCPOPTSACK_MAX_ENTRIES];
int vlen = strlen(v), num, i;
char *vcopy = alloca(vlen+1);
unsigned char *data = pkt->p_layer[layer].l_data;
memcpy(vcopy, v, vlen+1);
num = strftok("/", vcopy, bv, TCPOPTSACK_MAX_ENTRIES);
for (i = 0; i < num; i++) {
char *p;
__u32 s_origin, s_len;
p = strchr(bv[i], '-');
if (!p) {
ars_set_error(pkt, "Invalid syntax for tcp.sack blocks: '%s' (try ...tcp.sack(blocks=123342-10/12653-50/0-0/0-0)... )");
return -ARS_INVALID;
}
*p = '\0';
p++;
s_origin = htonl(ars_atou(bv[i]));
s_len = htonl(ars_atou(p));
memcpy(data+2+(i*8), &s_origin, 4);
memcpy(data+6+(i*8), &s_len, 4);
}
} else {
ars_set_error(pkt, "Invalid field for TCP.SACK layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_tcpopt_dumb(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_tcpopt *tcpopt;
ARS_DEF_LAYER;
tcpopt = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "optlen") == 0) {
tcpopt->len = ars_atou(v);
} else {
ars_set_error(pkt, "Invalid field for TCP.? layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_tcpopt_echo(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_tcpopt *tcpopt;
ARS_DEF_LAYER;
tcpopt = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "optlen") == 0) {
tcpopt->len = ars_atou(v);
} else if (strcasecmp(f, "info") == 0) {
u_int32_t info = htonl(ars_atou(v));
memcpy(tcpopt->un.echo.info, &info, 4);
} else {
ars_set_error(pkt, "Invalid field for TCP.ECHO layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_icmp(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_icmphdr *icmp;
ARS_DEF_LAYER;
icmp = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "type") == 0) {
icmp->type = ars_atou(v);
} else if (strcasecmp(f, "code") == 0) {
icmp->code = ars_atou(v);
} else if (strcasecmp(f, "cksum") == 0) {
icmp->checksum = htons(ars_atou(v));
pkt->p_layer[layer].l_flags |= ARS_TAKE_ICMP_CKSUM;
} else if (strcasecmp(f, "id") == 0) {
icmp->un.echo.id = htons(ars_atou(v));
} else if (strcasecmp(f, "seq") == 0) {
icmp->un.echo.sequence = htons(ars_atou(v));
} else if (strcasecmp(f, "gw") == 0) {
return ars_resolve(pkt, &icmp->un.gateway, v);
} else if (strcasecmp(f, "unused") == 0) {
icmp->un.gateway = htonl(ars_atou(v));
} else {
ars_set_error(pkt, "Invalid field for ICMP layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_d_set_igrp(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_igrphdr *igrp;
ARS_DEF_LAYER;
igrp = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "version") == 0) {
igrp->version = ars_atou(v);
} else if (strcasecmp(f, "opcode") == 0) {
if (strcasecmp(v, "update") == 0)
igrp->opcode = ARS_IGRP_OPCODE_UPDATE;
else if (strcasecmp(v, "request") == 0)
igrp->opcode = ARS_IGRP_OPCODE_REQUEST;
else
igrp->opcode = ars_atou(v);
} else if (strcasecmp(f, "cksum") == 0) {
igrp->checksum = htons(ars_atou(v));
pkt->p_layer[layer].l_flags |= ARS_TAKE_IGRP_CKSUM;
} else if (strcasecmp(f, "edition") == 0) {
igrp->edition = ars_atou(v);
} else if (strcasecmp(f, "autosys") == 0) {
igrp->autosys = htons(ars_atou(v));
} else if (strcasecmp(f, "interior") == 0) {
igrp->interior = htons(ars_atou(v));
} else if (strcasecmp(f, "system") == 0) {
igrp->system= htons(ars_atou(v));
} else if (strcasecmp(f, "exterior") == 0) {
igrp->exterior = htons(ars_atou(v));
} else {
ars_set_error(pkt, "Invalid field for IGRP layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
static int igrp_set_dest(unsigned char *d, char *v)
{
int l = strlen(v);
char *vcopy = alloca(l+1);
char *f0, *f1, *f2;
memcpy(vcopy, v, l+1);
f0 = vcopy;
if ((f1 = strchr(f0, '.')) == NULL)
return 1;
*f1++ = '\0';
if ((f2 = strchr(f1, '.')) == NULL)
return 1;
*f2++ = '\0';
if (!strisnum(f0) || !strisnum(f1) || !strisnum(f2))
return 1;
d[0] = ars_atou(f0);
d[1] = ars_atou(f1);
d[2] = ars_atou(f2);
return 0;
}
static void igrp_set_uint24(void *d, char *v)
{
__u32 t;
unsigned char *x;
t = htonl(ars_atou(v));
x = (unsigned char*) &t;
memcpy(d, x+1, 3);
}
int ars_d_set_igrpentry(struct ars_packet *pkt, int layer, char *f, char *v)
{
struct ars_igrpentry *entry;
ARS_DEF_LAYER;
entry = pkt->p_layer[layer].l_data;
if (strcasecmp(f, "dest") == 0) {
if (igrp_set_dest(entry->destination, v)) {
ars_set_error(pkt, "Invalid IGRP entry 'dest' field value: '%s'\n", v);
return -ARS_INVALID;
}
} else if (strcasecmp(f, "delay") == 0) {
igrp_set_uint24(entry->delay, v);
} else if (strcasecmp(f, "bandwidth") == 0) {
igrp_set_uint24(entry->bandwidth, v);
} else if (strcasecmp(f, "mtu") == 0) {
__u16 mtu = htons(ars_atou(v));
memcpy(entry->mtu, &mtu, 2);
} else if (strcasecmp(f, "reliability") == 0) {
entry->reliability = ars_atou(v);
} else if (strcasecmp(f, "load") == 0) {
entry->load = ars_atou(v);
} else if (strcasecmp(f, "hopcount") == 0) {
entry->hopcount = ars_atou(v);
} else {
ars_set_error(pkt, "Invalid field for IGRP.ENTRY layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
int ars_push_data(struct ars_packet *pkt, int layer, void *data, size_t size)
{
char *p;
int old_size;
ARS_DEF_LAYER;
old_size = pkt->p_layer[layer].l_size;
p = realloc(pkt->p_layer[layer].l_data, old_size + size);
if (p == NULL)
return -ARS_NOMEM;
memcpy(p+old_size, data, size);
pkt->p_layer[layer].l_data = p;
pkt->p_layer[layer].l_size += size;
return ARS_OK;
}
static int hextab[256];
static int hextab_initialized = 0;
static char *hexdig = "0123456789abcdef";
static char *ars_decode_hex(struct ars_packet *pkt, char *s, int *blen)
{
int len = strlen(s), i;
unsigned char *d, *saved;
if (len%2) {
ars_set_error(pkt, "Odd length of 'hex' data");
return NULL;
}
*blen = len/2;
if (!hextab_initialized) {
memset(hextab, 255, 255);
for (i = 0; i < 16; i++)
hextab[(int)hexdig[i]] = i;
}
if ((d = malloc(*blen)) == NULL) {
ars_set_error(pkt, "Out of memory decoding 'hex' data");
return NULL;
}
saved = d;
while(*s) {
int x0, x1;
x0 = hextab[tolower(*s)];
x1 = hextab[tolower(*(s+1))];
if (x0 == 255 || x1 == 255) {
ars_set_error(pkt, "Wrong byte for 'hex' data: '%c%c'",
*s, *(s+1));
free(saved);
return NULL;
}
*d++ = (x0 << 4) | x1;
s += 2;
}
return saved;
}
static char *ars_decode_string(struct ars_packet *pkt, char *s, int *blen)
{
int l = strlen(s), i;
int bl = 0;
unsigned char *d, *saved;
if (!hextab_initialized) {
memset(hextab, -1, 255);
for (i = 0; i < 16; i++)
hextab[(int)hexdig[i]] = i;
}
if ((d = malloc(l)) == NULL) {
ars_set_error(pkt, "Out of memory decoding 'str' data");
return NULL;
}
saved = d;
while(*s) {
if (*s == '\\' && *(s+1) && *(s+2)) {
*d++ = (hextab[(int)*(s+1)] << 4) + hextab[(int)*(s+2)];
s += 3;
} else {
*d++ = *s++;
}
bl++;
}
*blen = bl;
return saved;
}
#define ARS_DATA_BUF_SIZE 4096
int ars_d_set_data(struct ars_packet *pkt, int layer, char *f, char *v)
{
ARS_DEF_LAYER;
if (strcasecmp(f, "file") == 0) {
int fd, n_read;
unsigned char buffer[ARS_DATA_BUF_SIZE];
if ((fd = open(v, O_RDONLY)) == -1) {
ars_set_error(pkt, "Can't open the DATA file '%s': %s",
v, strerror(errno));
return -ARS_ERROR;
}
if ((n_read = read(fd, buffer, ARS_DATA_BUF_SIZE)) == -1) {
close(fd);
ars_set_error(pkt, "Can't read DATA from file: %s", strerror(errno));
return -ARS_ERROR;
}
close(fd);
if (n_read == 0)
return -ARS_OK;
return ars_push_data(pkt, layer, buffer, n_read);
} else if (strcasecmp(f, "str") == 0) {
char *binary;
int err, blen;
binary = ars_decode_string(pkt, v, &blen);
if (binary == NULL)
return -ARS_ERROR;
err = ars_push_data(pkt, layer, binary, blen);
free(binary);
return err;
} else if (strcasecmp(f, "hex") == 0) {
char *binary;
int err, blen;
binary = ars_decode_hex(pkt, v, &blen);
if (binary == NULL)
return -ARS_ERROR;
err = ars_push_data(pkt, layer, binary, blen);
free(binary);
} else if (strcasecmp(f, "uint32") == 0) {
int err;
__u32 t, nt;
t = ars_atou(v);
nt = htonl(t);
err = ars_push_data(pkt, layer, (char*)&nt, 4);
return err;
} else if (strcasecmp(f, "uint24") == 0) {
int err;
__u32 t, nt;
unsigned char *x = (unsigned char*) &nt;
t = ars_atou(v);
nt = htonl(t);
err = ars_push_data(pkt, layer, x+1, 3);
return err;
} else if (strcasecmp(f, "uint16") == 0) {
int err;
__u16 t, nt;
t = ars_atou(v);
nt = htons(t);
err = ars_push_data(pkt, layer, (char*)&nt, 2);
return err;
} else if (strcasecmp(f, "uint8") == 0) {
int err;
__u8 t;
t = ars_atou(v);
err = ars_push_data(pkt, layer, (char*)&t, 1);
return err;
} else {
ars_set_error(pkt, "Invalid field for DATA layer: '%s'", f);
return -ARS_INVALID;
}
return -ARS_OK;
}
/* A Finite state machine to build the packet using the description */
int ars_d_build(struct ars_packet *pkt, char *t)
{
struct ars_d_keyword_info *k = NULL;
char next[ARS_MAX_TSIZE];
char field[ARS_MAX_TSIZE];
int state = ARS_G_LAYER;
int error;
void *p;
while ((t = ars_d_parser(t, next, ARS_MAX_TSIZE)) != NULL) {
switch(state) {
case ARS_G_LAYER:
k = ars_get_keyword_by_name(next);
if (k == NULL) {
ars_set_error(pkt, "Unknown keyword: '%s'", next);
return -ARS_INVALID;
}
__D(printf("Adding a new layer (%s)\n", next);)
p = k->ki_add(pkt, k->ki_opt);
if (p == NULL)
return -ARS_INVALID;
state = ARS_G_OBRACE_OR_PLUS;
break;
case ARS_G_FIELD_OR_CBRACE:
if (next[0] == ')' && next[1] == '\0') {
state = ARS_G_LEN_OR_PLUS;
} else {
strncpy(field, next, ARS_MAX_TSIZE);
state = ARS_G_EQUAL;
}
break;
case ARS_G_VALUE:
if (k->ki_set == NULL) {
ars_set_error(pkt, "Field specified for"
"a layer that doesn't support fields");
return -ARS_INVALID;
}
error = k->ki_set(pkt, ARS_LAST_LAYER, field, next);
if (error != -ARS_OK)
return error;
state = ARS_G_COMMA_OR_CBRACE;
break;
case ARS_G_OBRACE_OR_PLUS:
if (next[0] == '(' && next[1] == '\0') {
state = ARS_G_FIELD_OR_CBRACE;
break;
} else if (next[0] == '+' && next[1] == '\0') {
state = ARS_G_LAYER;
break;
} else {
ars_set_error(pkt, "Missing brace or plus");
return -ARS_INVALID;
}
break;
case ARS_G_CBRACE:
if (next[0] != ')' || next[1] != '\0') {
ars_set_error(pkt, "Missing closed brace");
return -ARS_INVALID;
}
state = ARS_G_LEN_OR_PLUS;
break;
case ARS_G_COMMA_OR_CBRACE:
if (next[0] == ')' && next[1] == '\0') {
state = ARS_G_LEN_OR_PLUS;
break;
} else if (next[0] == ',' && next[1] == '\0') {
state = ARS_G_FIELD_OR_CBRACE;
break;
} else {
ars_set_error(pkt, "Missing brace or comma");
return -ARS_INVALID;
}
break;
case ARS_G_LEN_OR_PLUS:
if (next[0] == '+' && next[1] == '\0') {
state = ARS_G_LAYER;
break;
}
error = ars_d_setlayer_size(pkt, ARS_LAST_LAYER, next);
if (error != -ARS_OK)
return error;
state = ARS_G_PLUS;
break;
case ARS_G_PLUS:
if (next[0] != '+' || next[1] != '\0') {
ars_set_error(pkt, "Missing plus");
return -ARS_INVALID;
}
state = ARS_G_LAYER;
break;
case ARS_G_EQUAL:
if (next[0] != '=' || next[1] != '\0') {
ars_set_error(pkt, "Missing equal");
return -ARS_INVALID;
}
state = ARS_G_VALUE;
break;
}
}
if (state != ARS_G_LEN_OR_PLUS && state != ARS_G_PLUS &&
state != ARS_G_OBRACE_OR_PLUS) {
ars_set_error(pkt, "Packet description truncated");
return -ARS_INVALID;
}
return -ARS_OK;
}
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