From 5c6ad9785fa043bd5337dd8088f795f89fbcd931 Mon Sep 17 00:00:00 2001
From: laforge <laforge>
Date: Sun, 30 Jul 2000 19:33:09 +0000
Subject: Initial revision

---
 ulogd/libipulog/libipulog.c | 199 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 199 insertions(+)
 create mode 100644 ulogd/libipulog/libipulog.c

(limited to 'ulogd/libipulog/libipulog.c')

diff --git a/ulogd/libipulog/libipulog.c b/ulogd/libipulog/libipulog.c
new file mode 100644
index 0000000..725bb9f
--- /dev/null
+++ b/ulogd/libipulog/libipulog.c
@@ -0,0 +1,199 @@
+/* 
+ * libipulog.c, Version $Revision$
+ *
+ * netfilter ULOG userspace library.
+ *
+ * (C) 2000 by Harald Welte <laforge@sunbeam.franken.de>
+ * released under the terms of GNU GPL
+ *
+ * This library is still under development, so be aware of sudden interface
+ * changes
+ *
+ * $Id$
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <libipulog/libipulog.h>
+
+/* internal */
+
+enum 
+{
+	IPULOG_ERR_NONE = 0,
+	IPULOG_ERR_IMPL,
+	IPULOG_ERR_HANDLE,
+	IPULOG_ERR_SOCKET,
+	IPULOG_ERR_BIND,
+	IPULOG_ERR_RECVBUF,
+	IPULOG_ERR_RECV,
+	IPULOG_ERR_NLEOF,
+	IPULOG_ERR_TRUNC,
+	IPULOG_ERR_INVGR,
+};
+
+#define IPULOG_MAXERR IPULOG_ERR_INVGR
+
+static 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, "Receive buffer size invalid" },
+	{ IPULOG_ERR_NLEOF, "Received EOF on netlink socket" },
+	{ IPULOG_ERR_TRUNC, "Receive message truncated" },
+	{ IPULOG_ERR_INVGR, "Invalid group specified" },
+};
+
+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 || nlh->nlmsg_len > status)
+	{
+		ipulog_errno = IPULOG_ERR_TRUNC;
+		return -1;
+	}
+	return status;
+}
+
+static char *ipulog_strerror(int errcode)
+{
+	if (errcode < 0 || errcode > IPULOG_MAXERR)
+		errcode = IPULOG_ERR_IMPL;
+	return ipulog_errmap[errcode].message;
+}
+
+
+/* public */
+
+/* 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(unsigned int gmask)
+{
+	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;
+
+	return h;
+} 
+
+/* destroy a ipulog handle */
+int ipulog_destroy_handle(struct ipulog_handle *h)
+{
+	if (h)
+	{
+		close(h->fd);
+		free(h);
+	}
+}
+
+int ipulog_set_mode()
+{
+}
+
+/* do a BLOCKING read on an ipulog handle */
+ssize_t ipulog_read(const 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(const unsigned char *buf)
+{
+	return NLMSG_DATA((struct nlmsghdr *) buf);
+}
+
+/* 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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