xref: /aosp_15_r20/external/iptables/extensions/libxt_set.h (revision a71a954618bbadd4a345637e5edcf36eec826889)

#ifndef _LIBXT_SET_H
#define _LIBXT_SET_H

#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>

static int
get_version(unsigned *version)
{
	int res, sockfd = socket(AF_INET, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_RAW);
	struct ip_set_req_version req_version;
	socklen_t size = sizeof(req_version);

	if (sockfd < 0)
		xtables_error(OTHER_PROBLEM,
			      "Can't open socket to ipset.\n");

	req_version.op = IP_SET_OP_VERSION;
	res = getsockopt(sockfd, SOL_IP, SO_IP_SET, &req_version, &size);
	if (res != 0)
		xtables_error(OTHER_PROBLEM,
			      "Kernel module xt_set is not loaded in.\n");

	*version = req_version.version;

	return sockfd;
}

static void
get_set_byid(char *setname, ip_set_id_t idx)
{
	struct ip_set_req_get_set req;
	socklen_t size = sizeof(struct ip_set_req_get_set);
	int res, sockfd;

	sockfd = get_version(&req.version);
	req.op = IP_SET_OP_GET_BYINDEX;
	req.set.index = idx;
	res = getsockopt(sockfd, SOL_IP, SO_IP_SET, &req, &size);
	close(sockfd);

	if (res != 0)
		xtables_error(OTHER_PROBLEM,
			"Problem when communicating with ipset, errno=%d.\n",
			errno);
	if (size != sizeof(struct ip_set_req_get_set))
		xtables_error(OTHER_PROBLEM,
			"Incorrect return size from kernel during ipset lookup, "
			"(want %zu, got %zu)\n",
			sizeof(struct ip_set_req_get_set), (size_t)size);
	if (req.set.name[0] == '\0')
		xtables_error(PARAMETER_PROBLEM,
			"Set with index %i in kernel doesn't exist.\n", idx);

	strncpy(setname, req.set.name, IPSET_MAXNAMELEN);
}

static void
get_set_byname_only(const char *setname, struct xt_set_info *info,
		    int sockfd, unsigned int version)
{
	struct ip_set_req_get_set req = { .version = version };
	socklen_t size = sizeof(struct ip_set_req_get_set);
	int res;

	req.op = IP_SET_OP_GET_BYNAME;
	strncpy(req.set.name, setname, IPSET_MAXNAMELEN);
	req.set.name[IPSET_MAXNAMELEN - 1] = '\0';
	res = getsockopt(sockfd, SOL_IP, SO_IP_SET, &req, &size);
	close(sockfd);

	if (res != 0)
		xtables_error(OTHER_PROBLEM,
			"Problem when communicating with ipset, errno=%d.\n",
			errno);
	if (size != sizeof(struct ip_set_req_get_set))
		xtables_error(OTHER_PROBLEM,
			"Incorrect return size from kernel during ipset lookup, "
			"(want %zu, got %zu)\n",
			sizeof(struct ip_set_req_get_set), (size_t)size);
	if (req.set.index == IPSET_INVALID_ID)
		xtables_error(PARAMETER_PROBLEM,
			      "Set %s doesn't exist.\n", setname);

	info->index = req.set.index;
}

static void
get_set_byname(const char *setname, struct xt_set_info *info)
{
	struct ip_set_req_get_set_family req;
	socklen_t size = sizeof(struct ip_set_req_get_set_family);
	int res, sockfd, version;

	sockfd = get_version(&req.version);
	version = req.version;
	req.op = IP_SET_OP_GET_FNAME;
	strncpy(req.set.name, setname, IPSET_MAXNAMELEN);
	req.set.name[IPSET_MAXNAMELEN - 1] = '\0';
	res = getsockopt(sockfd, SOL_IP, SO_IP_SET, &req, &size);

	if (res != 0 && errno == EBADMSG)
		/* Backward compatibility */
		return get_set_byname_only(setname, info, sockfd, version);

	close(sockfd);
	if (res != 0)
		xtables_error(OTHER_PROBLEM,
			"Problem when communicating with ipset, errno=%d.\n",
			errno);
	if (size != sizeof(struct ip_set_req_get_set_family))
		xtables_error(OTHER_PROBLEM,
			"Incorrect return size from kernel during ipset lookup, "
			"(want %zu, got %zu)\n",
			sizeof(struct ip_set_req_get_set_family),
			(size_t)size);
	if (req.set.index == IPSET_INVALID_ID)
		xtables_error(PARAMETER_PROBLEM,
			      "Set %s doesn't exist.\n", setname);
	if (!(req.family == afinfo->family ||
	      req.family == NFPROTO_UNSPEC))
		xtables_error(PARAMETER_PROBLEM,
			      "The protocol family of set %s is %s, "
			      "which is not applicable.\n",
			      setname,
			      req.family == NFPROTO_IPV4 ? "IPv4" : "IPv6");

	info->index = req.set.index;
}

static void
parse_dirs_v0(const char *opt_arg, struct xt_set_info_v0 *info)
{
	char *saved = xtables_strdup(opt_arg);
	char *ptr, *tmp = saved;
	int i = 0;

	while (i < (IPSET_DIM_MAX - 1) && tmp != NULL) {
		ptr = strsep(&tmp, ",");
		if (strncmp(ptr, "src", 3) == 0)
			info->u.flags[i++] |= IPSET_SRC;
		else if (strncmp(ptr, "dst", 3) == 0)
			info->u.flags[i++] |= IPSET_DST;
		else
			xtables_error(PARAMETER_PROBLEM,
				"You must spefify (the comma separated list of) 'src' or 'dst'.");
	}

	if (tmp)
		xtables_error(PARAMETER_PROBLEM,
			      "Can't be more src/dst options than %i.",
			      IPSET_DIM_MAX);

	free(saved);
}

static void
parse_dirs(const char *opt_arg, struct xt_set_info *info)
{
	char *saved = xtables_strdup(opt_arg);
	char *ptr, *tmp = saved;

	while (info->dim < IPSET_DIM_MAX && tmp != NULL) {
		info->dim++;
		ptr = strsep(&tmp, ",");
		if (strncmp(ptr, "src", 3) == 0)
			info->flags |= (1 << info->dim);
		else if (strncmp(ptr, "dst", 3) != 0)
			xtables_error(PARAMETER_PROBLEM,
				"You must spefify (the comma separated list of) 'src' or 'dst'.");
	}

	if (tmp)
		xtables_error(PARAMETER_PROBLEM,
			      "Can't be more src/dst options than %i.",
			      IPSET_DIM_MAX);

	free(saved);
}

#endif /*_LIBXT_SET_H*/