+++ /dev/null
-/*
- * libipulog.c, $Revision: 1.1.2.1 $
- *
- * netfilter ULOG userspace library.
- *
- * (C) 2000-2001 by Harald Welte <laforge@gnumonks.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2
- * as published by the Free Software Foundation
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * This library is still under development, so be aware of sudden interface
- * changes
- *
- * $Id: libipulog.c,v 1.1.2.1 2004/08/13 21:03:10 sla Exp $
- */
-
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-#include <net/if.h>
-#include <libipulog/libipulog.h>
-
-struct ipulog_handle
-{
- int fd;
- u_int8_t blocking;
- struct sockaddr_nl local;
- struct sockaddr_nl peer;
- struct nlmsghdr* last_nlhdr;
-};
-
-/* internal */
-
-
-int ipulog_errno = IPULOG_ERR_NONE;
-
-struct ipulog_errmap_t
-{
- int errcode;
- char *message;
-} ipulog_errmap[] =
-{
- { IPULOG_ERR_NONE, "No error" },
- { IPULOG_ERR_IMPL, "Not implemented yet" },
- { IPULOG_ERR_HANDLE, "Unable to create netlink handle" },
- { IPULOG_ERR_SOCKET, "Unable to create netlink socket" },
- { IPULOG_ERR_BIND, "Unable to bind netlink socket" },
- { IPULOG_ERR_RECVBUF, "Receive buffer size invalid" },
- { IPULOG_ERR_RECV, "Error during netlink receive" },
- { IPULOG_ERR_NLEOF, "Received EOF on netlink socket" },
- { IPULOG_ERR_TRUNC, "Receive message truncated" },
- { IPULOG_ERR_INVGR, "Invalid group specified" },
- { IPULOG_ERR_INVNL, "Invalid netlink message" },
-};
-
-static ssize_t
-ipulog_netlink_recvfrom(const struct ipulog_handle *h,
- unsigned char *buf, size_t len)
-{
- int addrlen, status;
- struct nlmsghdr *nlh;
-
- if (len < sizeof(struct nlmsgerr)) {
- ipulog_errno = IPULOG_ERR_RECVBUF;
- return -1;
- }
- addrlen = sizeof(h->peer);
- status = recvfrom(h->fd, buf, len, 0, (struct sockaddr *)&h->peer,
- &addrlen);
- if (status < 0)
- {
- ipulog_errno = IPULOG_ERR_RECV;
- return status;
- }
- if (addrlen != sizeof (h->peer))
- {
- ipulog_errno = IPULOG_ERR_RECV;
- return -1;
- }
- if (status == 0)
- {
- ipulog_errno = IPULOG_ERR_NLEOF;
- return -1;
- }
- nlh = (struct nlmsghdr *)buf;
- if (nlh->nlmsg_flags & MSG_TRUNC || status > len)
- {
- ipulog_errno = IPULOG_ERR_TRUNC;
- return -1;
- }
- return status;
-}
-
-/* public */
-
-char *ipulog_strerror(int errcode)
-{
- if (errcode < 0 || errcode > IPULOG_MAXERR)
- errcode = IPULOG_ERR_IMPL;
- return ipulog_errmap[errcode].message;
-}
-
-/* convert a netlink group (1-32) to a group_mask suitable for create_handle */
-u_int32_t ipulog_group2gmask(u_int32_t group)
-{
- if (group < 1 || group > 32)
- {
- ipulog_errno = IPULOG_ERR_INVGR;
- return 0;
- }
- return (1 << (group - 1));
-}
-
-/* create a ipulog handle for the reception of packets sent to gmask */
-struct ipulog_handle *ipulog_create_handle(u_int32_t gmask,
- u_int32_t rcvbufsize)
-{
- struct ipulog_handle *h;
- int status;
-
- h = (struct ipulog_handle *) malloc(sizeof(struct ipulog_handle));
- if (h == NULL)
- {
- ipulog_errno = IPULOG_ERR_HANDLE;
- return NULL;
- }
- memset(h, 0, sizeof(struct ipulog_handle));
- h->fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_NFLOG);
- if (h->fd == -1)
- {
- ipulog_errno = IPULOG_ERR_SOCKET;
- close(h->fd);
- free(h);
- return NULL;
- }
- memset(&h->local, 0, sizeof(struct sockaddr_nl));
- h->local.nl_family = AF_NETLINK;
- h->local.nl_pid = getpid();
- h->local.nl_groups = gmask;
- status = bind(h->fd, (struct sockaddr *)&h->local, sizeof(h->local));
- if (status == -1)
- {
- ipulog_errno = IPULOG_ERR_BIND;
- close(h->fd);
- free(h);
- return NULL;
- }
- memset(&h->peer, 0, sizeof(struct sockaddr_nl));
- h->peer.nl_family = AF_NETLINK;
- h->peer.nl_pid = 0;
- h->peer.nl_groups = gmask;
-
- status = setsockopt(h->fd, SOL_SOCKET, SO_RCVBUF, &rcvbufsize,
- sizeof(rcvbufsize));
- if (status == -1)
- {
- ipulog_errno = IPULOG_ERR_RECVBUF;
- close(h->fd);
- free(h);
- return NULL;
- }
-
- return h;
-}
-
-/* destroy a ipulog handle */
-void ipulog_destroy_handle(struct ipulog_handle *h)
-{
- close(h->fd);
- free(h);
-}
-
-#if 0
-int ipulog_set_mode()
-{
-}
-#endif
-
-/* do a BLOCKING read on an ipulog handle */
-ssize_t ipulog_read(struct ipulog_handle *h, unsigned char *buf,
- size_t len, int timeout)
-{
- return ipulog_netlink_recvfrom(h, buf, len);
-}
-
-/* get a pointer to the actual start of the ipulog packet,
- use this to strip netlink header */
-ulog_packet_msg_t *ipulog_get_packet(struct ipulog_handle *h,
- const unsigned char *buf,
- size_t len)
-{
- struct nlmsghdr *nlh;
- size_t remain_len;
-
- /* if last header in handle not inside this buffer,
- * drop reference to last header */
- if ((unsigned char *)h->last_nlhdr > (buf + len) ||
- (unsigned char *)h->last_nlhdr < buf) {
- h->last_nlhdr = NULL;
- }
-
- if (!h->last_nlhdr) {
- /* fist message in buffer */
- nlh = (struct nlmsghdr *) buf;
- if (!NLMSG_OK(nlh, len)) {
- /* ERROR */
- ipulog_errno = IPULOG_ERR_INVNL;
- return NULL;
- }
- } else {
- /* we are in n-th part of multilink message */
- if (h->last_nlhdr->nlmsg_type == NLMSG_DONE ||
- !(h->last_nlhdr->nlmsg_flags & NLM_F_MULTI)) {
- /* if last part in multilink message,
- * or no multipart message at all: return */
- h->last_nlhdr = NULL;
- return NULL;
- }
-
- /* calculate remaining lenght from lasthdr to end of buffer */
- remain_len = (len -
- ((unsigned char *)h->last_nlhdr - buf));
- nlh = NLMSG_NEXT(h->last_nlhdr, remain_len);
- }
-
- h->last_nlhdr = nlh;
-
- return NLMSG_DATA(nlh);
-}
-
-/* print a human readable description of the last error to stderr */
-void ipulog_perror(const char *s)
-{
- if (s)
- fputs(s, stderr);
- else
- fputs("ERROR", stderr);
- if (ipulog_errno)
- fprintf(stderr, ": %s", ipulog_strerror(ipulog_errno));
- if (errno)
- fprintf(stderr, ": %s", strerror(errno));
- fputc('\n', stderr);
-}
-
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