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#include <getopt.h>
#include <libgen.h>
#include <netdb.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <xtables.h>
#include "xshared.h"
/*
* Print out any special helps. A user might like to be able to add a --help
* to the commandline, and see expected results. So we call help for all
* specified matches and targets.
*/
void print_extension_helps(const struct xtables_target *t,
const struct xtables_rule_match *m)
{
for (; t != NULL; t = t->next) {
if (t->used) {
printf("\n");
if (t->help == NULL)
printf("%s does not take any options\n",
t->name);
else
t->help();
}
}
for (; m != NULL; m = m->next) {
printf("\n");
if (m->match->help == NULL)
printf("%s does not take any options\n",
m->match->name);
else
m->match->help();
}
}
const char *
proto_to_name(uint8_t proto, int nolookup)
{
unsigned int i;
if (proto && !nolookup) {
struct protoent *pent = getprotobynumber(proto);
if (pent)
return pent->p_name;
}
for (i = 0; xtables_chain_protos[i].name != NULL; ++i)
if (xtables_chain_protos[i].num == proto)
return xtables_chain_protos[i].name;
return NULL;
}
static struct xtables_match *
find_proto(const char *pname, enum xtables_tryload tryload,
int nolookup, struct xtables_rule_match **matches)
{
unsigned int proto;
if (xtables_strtoui(pname, NULL, &proto, 0, UINT8_MAX)) {
const char *protoname = proto_to_name(proto, nolookup);
if (protoname)
return xtables_find_match(protoname, tryload, matches);
} else
return xtables_find_match(pname, tryload, matches);
return NULL;
}
/*
* Some explanations (after four different bugs in 3 different releases): If
* we encounter a parameter, that has not been parsed yet, it's not an option
* of an explicitly loaded match or a target. However, we support implicit
* loading of the protocol match extension. '-p tcp' means 'l4 proto 6' and at
* the same time 'load tcp protocol match on demand if we specify --dport'.
*
* To make this work, we need to make sure:
* - the parameter has not been parsed by a match (m above)
* - a protocol has been specified
* - the protocol extension has not been loaded yet, or is loaded and unused
* [think of ip6tables-restore!]
* - the protocol extension can be successively loaded
*/
static bool should_load_proto(struct iptables_command_state *cs)
{
if (cs->protocol == NULL)
return false;
if (find_proto(cs->protocol, XTF_DONT_LOAD,
cs->options & OPT_NUMERIC, NULL) == NULL)
return true;
return !cs->proto_used;
}
struct xtables_match *load_proto(struct iptables_command_state *cs)
{
if (!should_load_proto(cs))
return NULL;
return find_proto(cs->protocol, XTF_TRY_LOAD,
cs->options & OPT_NUMERIC, &cs->matches);
}
void command_default(struct iptables_command_state *cs,
struct xtables_globals *gl)
{
struct xtables_rule_match *matchp;
struct xtables_match *m;
if (cs->target != NULL &&
(cs->target->parse != NULL || cs->target->x6_parse != NULL) &&
cs->c >= cs->target->option_offset &&
cs->c < cs->target->option_offset + XT_OPTION_OFFSET_SCALE) {
xtables_option_tpcall(cs->c, cs->argv, cs->invert,
cs->target, &cs->fw);
return;
}
for (matchp = cs->matches; matchp; matchp = matchp->next) {
m = matchp->match;
if (matchp->completed ||
(m->x6_parse == NULL && m->parse == NULL))
continue;
if (cs->c < matchp->match->option_offset ||
cs->c >= matchp->match->option_offset + XT_OPTION_OFFSET_SCALE)
continue;
xtables_option_mpcall(cs->c, cs->argv, cs->invert, m, &cs->fw);
return;
}
/* Try loading protocol */
m = load_proto(cs);
if (m != NULL) {
size_t size;
cs->proto_used = 1;
size = XT_ALIGN(sizeof(struct ip6t_entry_match)) + m->size;
m->m = xtables_calloc(1, size);
m->m->u.match_size = size;
strcpy(m->m->u.user.name, m->name);
m->m->u.user.revision = m->revision;
if (m->init != NULL)
m->init(m->m);
if (m->x6_options != NULL)
gl->opts = xtables_options_xfrm(gl->orig_opts,
gl->opts,
m->x6_options,
&m->option_offset);
else
gl->opts = xtables_merge_options(gl->orig_opts,
gl->opts,
m->extra_opts,
&m->option_offset);
if (gl->opts == NULL)
xtables_error(OTHER_PROBLEM, "can't alloc memory!");
optind--;
return;
}
if (cs->c == ':')
xtables_error(PARAMETER_PROBLEM, "option \"%s\" "
"requires an argument", cs->argv[optind-1]);
if (cs->c == '?')
xtables_error(PARAMETER_PROBLEM, "unknown option "
"\"%s\"", cs->argv[optind-1]);
xtables_error(PARAMETER_PROBLEM, "Unknown arg \"%s\"", optarg);
}
static mainfunc_t subcmd_get(const char *cmd, const struct subcommand *cb)
{
for (; cb->name != NULL; ++cb)
if (strcmp(cb->name, cmd) == 0)
return cb->main;
return NULL;
}
int subcmd_main(int argc, char **argv, const struct subcommand *cb)
{
const char *cmd = basename(*argv);
mainfunc_t f = subcmd_get(cmd, cb);
if (f == NULL && argc > 1) {
/*
* Unable to find a main method for our command name?
* Let's try again with the first argument!
*/
++argv;
--argc;
f = subcmd_get(*argv, cb);
}
/* now we should have a valid function pointer */
if (f != NULL)
return f(argc, argv);
fprintf(stderr, "ERROR: No valid subcommand given.\nValid subcommands:\n");
for (; cb->name != NULL; ++cb)
fprintf(stderr, " * %s\n", cb->name);
exit(EXIT_FAILURE);
}
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