blob: 4fdd189d7d9c6c01c9768249adccb35d3f9b66f6 [file] [log] [blame]
/*
* m_pedit.c generic packet editor actions module
*
* This program is free software; you can distribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: J Hadi Salim (hadi@cyberus.ca)
*
* TODO:
* 1) Big endian broken in some spots
* 2) A lot of this stuff was added on the fly; get a big double-double
* and clean it up at some point.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <dlfcn.h>
#include "utils.h"
#include "tc_util.h"
#include "m_pedit.h"
static struct m_pedit_util *pedit_list;
static int pedit_debug;
static void
explain(void)
{
fprintf(stderr, "Usage: ... pedit munge <MUNGE>\n");
fprintf(stderr,
"Where: MUNGE := <RAW>|<LAYERED>\n"
"\t<RAW>:= <OFFSETC>[ATC]<CMD>\n "
"\t\tOFFSETC:= offset <offval> <u8|u16|u32>\n "
"\t\tATC:= at <atval> offmask <maskval> shift <shiftval>\n "
"\t\tNOTE: offval is byte offset, must be multiple of 4\n "
"\t\tNOTE: maskval is a 32 bit hex number\n "
"\t\tNOTE: shiftval is a is a shift value\n "
"\t\tCMD:= clear | invert | set <setval>| retain\n "
"\t<LAYERED>:= ip <ipdata> | ip6 <ip6data> \n "
" \t\t| udp <udpdata> | tcp <tcpdata> | icmp <icmpdata> \n"
"For Example usage look at the examples directory\n");
}
static void
usage(void)
{
explain();
exit(-1);
}
static int
pedit_parse_nopopt (int *argc_p, char ***argv_p,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
{
int argc = *argc_p;
char **argv = *argv_p;
if (argc) {
fprintf(stderr, "Unknown action hence option \"%s\" is unparsable\n", *argv);
return -1;
}
return 0;
}
static struct m_pedit_util *get_pedit_kind(const char *str)
{
static void *pBODY;
void *dlh;
char buf[256];
struct m_pedit_util *p;
for (p = pedit_list; p; p = p->next) {
if (strcmp(p->id, str) == 0)
return p;
}
snprintf(buf, sizeof(buf), "p_%s.so", str);
dlh = dlopen(buf, RTLD_LAZY);
if (dlh == NULL) {
dlh = pBODY;
if (dlh == NULL) {
dlh = pBODY = dlopen(NULL, RTLD_LAZY);
if (dlh == NULL)
goto noexist;
}
}
snprintf(buf, sizeof(buf), "p_pedit_%s", str);
p = dlsym(dlh, buf);
if (p == NULL)
goto noexist;
reg:
p->next = pedit_list;
pedit_list = p;
return p;
noexist:
p = malloc(sizeof(*p));
if (p) {
memset(p, 0, sizeof(*p));
strncpy(p->id, str, sizeof(p->id)-1);
p->parse_peopt = pedit_parse_nopopt;
goto reg;
}
return p;
}
int
pack_key(struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
{
int hwm = sel->nkeys;
if (hwm >= MAX_OFFS)
return -1;
if (tkey->off % 4) {
fprintf(stderr, "offsets MUST be in 32 bit boundaries\n");
return -1;
}
sel->keys[hwm].val = tkey->val;
sel->keys[hwm].mask = tkey->mask;
sel->keys[hwm].off = tkey->off;
sel->keys[hwm].at = tkey->at;
sel->keys[hwm].offmask = tkey->offmask;
sel->keys[hwm].shift = tkey->shift;
sel->nkeys++;
return 0;
}
int
pack_key32(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
{
if (tkey->off > (tkey->off & ~3)) {
fprintf(stderr,
"pack_key32: 32 bit offsets must begin in 32bit boundaries\n");
return -1;
}
tkey->val = htonl(tkey->val & retain);
tkey->mask = htonl(tkey->mask | ~retain);
/* jamal remove this - it is not necessary given the if check above */
tkey->off &= ~3;
return pack_key(sel,tkey);
}
int
pack_key16(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
{
int ind, stride;
__u32 m[4] = {0xFFFF0000,0xFF0000FF,0x0000FFFF};
if (tkey->val > 0xFFFF || tkey->mask > 0xFFFF) {
fprintf(stderr, "pack_key16 bad value\n");
return -1;
}
ind = tkey->off & 3;
if (ind == 3) {
fprintf(stderr, "pack_key16 bad index value %d\n",ind);
return -1;
}
stride = 8 * ind;
tkey->val = htons(tkey->val);
tkey->val <<= stride;
tkey->mask <<= stride;
retain <<= stride;
tkey->mask = retain|m[ind];
tkey->off &= ~3;
if (pedit_debug)
printf("pack_key16: Final val %08x mask %08x \n",tkey->val,tkey->mask);
return pack_key(sel,tkey);
}
int
pack_key8(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
{
int ind, stride;
__u32 m[4] = {0xFFFFFF00,0xFFFF00FF,0xFF00FFFF,0x00FFFFFF};
if (tkey->val > 0xFF || tkey->mask > 0xFF) {
fprintf(stderr, "pack_key8 bad value (val %x mask %x\n", tkey->val, tkey->mask);
return -1;
}
ind = tkey->off & 3;
stride = 8 * ind;
tkey->val <<= stride;
tkey->mask <<= stride;
retain <<= stride;
tkey->mask = retain|m[ind];
tkey->off &= ~3;
if (pedit_debug)
printf("pack_key8: Final word off %d val %08x mask %08x \n",tkey->off , tkey->val,tkey->mask);
return pack_key(sel,tkey);
}
int
parse_val(int *argc_p, char ***argv_p, __u32 * val, int type)
{
int argc = *argc_p;
char **argv = *argv_p;
if (argc <= 0)
return -1;
if (TINT == type)
return get_integer((int *) val, *argv, 0);
if (TU32 == type)
return get_u32(val, *argv, 0);
if (TIPV4 == type) {
inet_prefix addr;
if (get_prefix_1(&addr, *argv, AF_INET)) {
return -1;
}
*val=addr.data[0];
return 0;
}
if (TIPV6 == type) {
/* not implemented yet */
return -1;
}
return -1;
}
int
parse_cmd(int *argc_p, char ***argv_p, __u32 len, int type,__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
{
__u32 mask = 0, val = 0;
__u32 o = 0xFF;
int res = -1;
int argc = *argc_p;
char **argv = *argv_p;
if (argc <= 0)
return -1;
if (pedit_debug)
printf("parse_cmd argc %d %s offset %d length %d\n",argc,*argv,tkey->off,len);
if (len == 2)
o = 0xFFFF;
if (len == 4)
o = 0xFFFFFFFF;
if (matches(*argv, "invert") == 0) {
retain = val = mask = o;
} else if (matches(*argv, "set") == 0) {
NEXT_ARG();
if (parse_val(&argc, &argv, &val, type))
return -1;
} else if (matches(*argv, "preserve") == 0) {
retain = mask = o;
} else {
if (matches(*argv, "clear") != 0)
return -1;
}
argc--; argv++;
if (argc && matches(*argv, "retain") == 0) {
NEXT_ARG();
if (parse_val(&argc, &argv, &retain, TU32))
return -1;
argc--; argv++;
}
tkey->val = val;
if (len == 1) {
tkey->mask = 0xFF;
res = pack_key8(retain,sel,tkey);
goto done;
}
if (len == 2) {
tkey->mask = mask;
res = pack_key16(retain,sel,tkey);
goto done;
}
if (len == 4) {
tkey->mask = mask;
res = pack_key32(retain,sel,tkey);
goto done;
}
return -1;
done:
if (pedit_debug)
printf("parse_cmd done argc %d %s offset %d length %d\n",argc,*argv,tkey->off,len);
*argc_p = argc;
*argv_p = argv;
return res;
}
int
parse_offset(int *argc_p, char ***argv_p,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
{
int off;
__u32 len, retain;
int argc = *argc_p;
char **argv = *argv_p;
int res = -1;
if (argc <= 0)
return -1;
if (get_integer(&off, *argv, 0))
return -1;
tkey->off = off;
argc--;
argv++;
if (argc <= 0)
return -1;
if (matches(*argv, "u32") == 0) {
len = 4;
retain = 0xFFFFFFFF;
goto done;
}
if (matches(*argv, "u16") == 0) {
len = 2;
retain = 0x0;
goto done;
}
if (matches(*argv, "u8") == 0) {
len = 1;
retain = 0x0;
goto done;
}
return -1;
done:
NEXT_ARG();
/* [at <someval> offmask <maskval> shift <shiftval>] */
if (matches(*argv, "at") == 0) {
__u32 atv=0,offmask=0x0,shift=0;
NEXT_ARG();
if (get_u32(&atv, *argv, 0))
return -1;
tkey->at = atv;
NEXT_ARG();
if (get_u32(&offmask, *argv, 16))
return -1;
tkey->offmask = offmask;
NEXT_ARG();
if (get_u32(&shift, *argv, 0))
return -1;
tkey->shift = shift;
NEXT_ARG();
}
res = parse_cmd(&argc, &argv, len, TU32,retain,sel,tkey);
*argc_p = argc;
*argv_p = argv;
return res;
}
static int
parse_munge(int *argc_p, char ***argv_p,struct tc_pedit_sel *sel)
{
struct tc_pedit_key tkey;
int argc = *argc_p;
char **argv = *argv_p;
int res = -1;
if (argc <= 0)
return -1;
memset(&tkey, 0, sizeof(tkey));
if (matches(*argv, "offset") == 0) {
NEXT_ARG();
res = parse_offset(&argc, &argv,sel,&tkey);
goto done;
} else {
char k[16];
struct m_pedit_util *p = NULL;
strncpy(k, *argv, sizeof (k) - 1);
if (argc > 0 ) {
p = get_pedit_kind(k);
if (NULL == p)
goto bad_val;
res = p->parse_peopt(&argc, &argv, sel,&tkey);
if (res < 0) {
fprintf(stderr,"bad pedit parsing\n");
goto bad_val;
}
goto done;
}
}
bad_val:
return -1;
done:
*argc_p = argc;
*argv_p = argv;
return res;
}
int
parse_pedit(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n)
{
struct {
struct tc_pedit_sel sel;
struct tc_pedit_key keys[MAX_OFFS];
} sel;
int argc = *argc_p;
char **argv = *argv_p;
int ok = 0, iok = 0;
struct rtattr *tail;
memset(&sel, 0, sizeof(sel));
while (argc > 0) {
if (pedit_debug > 1)
fprintf(stderr, "while pedit (%d:%s)\n",argc, *argv);
if (matches(*argv, "pedit") == 0) {
NEXT_ARG();
ok++;
continue;
} else if (matches(*argv, "help") == 0) {
usage();
} else if (matches(*argv, "munge") == 0) {
if (!ok) {
fprintf(stderr, "Illegal pedit construct (%s) \n", *argv);
explain();
return -1;
}
NEXT_ARG();
if (parse_munge(&argc, &argv,&sel.sel)) {
fprintf(stderr, "Illegal pedit construct (%s) \n", *argv);
explain();
return -1;
}
ok++;
} else {
break;
}
}
if (!ok) {
explain();
return -1;
}
if (argc) {
if (matches(*argv, "reclassify") == 0) {
sel.sel.action = TC_ACT_RECLASSIFY;
NEXT_ARG();
} else if (matches(*argv, "pipe") == 0) {
sel.sel.action = TC_ACT_PIPE;
NEXT_ARG();
} else if (matches(*argv, "drop") == 0 ||
matches(*argv, "shot") == 0) {
sel.sel.action = TC_ACT_SHOT;
NEXT_ARG();
} else if (matches(*argv, "continue") == 0) {
sel.sel.action = TC_ACT_UNSPEC;
NEXT_ARG();
} else if (matches(*argv, "pass") == 0) {
sel.sel.action = TC_ACT_OK;
NEXT_ARG();
}
}
if (argc) {
if (matches(*argv, "index") == 0) {
NEXT_ARG();
if (get_u32(&sel.sel.index, *argv, 10)) {
fprintf(stderr, "Pedit: Illegal \"index\"\n");
return -1;
}
argc--;
argv++;
iok++;
}
}
tail = NLMSG_TAIL(n);
addattr_l(n, MAX_MSG, tca_id, NULL, 0);
addattr_l(n, MAX_MSG, TCA_PEDIT_PARMS,&sel, sizeof(sel.sel)+sel.sel.nkeys*sizeof(struct tc_pedit_key));
tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
*argc_p = argc;
*argv_p = argv;
return 0;
}
int
print_pedit(struct action_util *au,FILE * f, struct rtattr *arg)
{
struct tc_pedit_sel *sel;
struct rtattr *tb[TCA_PEDIT_MAX + 1];
SPRINT_BUF(b1);
if (arg == NULL)
return -1;
parse_rtattr_nested(tb, TCA_PEDIT_MAX, arg);
if (tb[TCA_PEDIT_PARMS] == NULL) {
fprintf(f, "[NULL pedit parameters]");
return -1;
}
sel = RTA_DATA(tb[TCA_PEDIT_PARMS]);
fprintf(f, " pedit action %s keys %d\n ", action_n2a(sel->action, b1, sizeof (b1)),sel->nkeys);
fprintf(f, "\t index %d ref %d bind %d", sel->index,sel->refcnt, sel->bindcnt);
if (show_stats) {
if (tb[TCA_PEDIT_TM]) {
struct tcf_t *tm = RTA_DATA(tb[TCA_PEDIT_TM]);
print_tm(f,tm);
}
}
if (sel->nkeys) {
int i;
struct tc_pedit_key *key = sel->keys;
for (i=0; i<sel->nkeys; i++, key++) {
fprintf(f, "\n\t key #%d",i);
fprintf(f, " at %d: val %08x mask %08x",
(unsigned int)key->off,
(unsigned int)ntohl(key->val),
(unsigned int)ntohl(key->mask));
}
} else {
fprintf(f, "\npedit %x keys %d is not LEGIT", sel->index,sel->nkeys);
}
fprintf(f, "\n ");
return 0;
}
int
pedit_print_xstats(struct action_util *au, FILE *f, struct rtattr *xstats)
{
return 0;
}
struct action_util pedit_action_util = {
.id = "pedit",
.parse_aopt = parse_pedit,
.print_aopt = print_pedit,
};