Initial revision

diff --git a/libipulog/libipulog.c b/libipulog/libipulog.c
new file mode 100644 (file)
index 0000000..725bb9f
--- /dev/null
+++ b/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);
+}
+

diff --git a/libipulog/ulog_test.c b/libipulog/ulog_test.c
new file mode 100644 (file)
index 0000000..7fa6504
--- /dev/null
+++ b/libipulog/ulog_test.c
@@ -0,0 +1,72 @@
+/* ulog_test, Version $Revision$
+ *
+ * small testing program for libipulog, part of the netfilter ULOG target
+ * for the linux 2.4 netfilter subsystem.
+ *
+ * (C) 2000 by Harald Welte <laforge@sunbeam.franken.de>
+ *
+ * this code is released under the terms of GNU GPL
+ *
+ * $Id$
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <libipulog/libipulog.h>
+
+#define MYBUFSIZ 2048
+
+/* prints some logging about a single packet */
+void handle_packet(ulog_packet_msg_t *pkt)
+{
+       unsigned char *p;
+       int i;
+       
+       printf("Hook=%u Mark=%u len=%d ", pkt->hook, pkt->mark, pkt->data_len);
+       if (strlen(pkt->prefix))
+               printf("Prefix=%s ", pkt->prefix);
+       
+       if (pkt->mac_len)
+       {
+               printf("mac=");
+               p = pkt->mac;
+               for (i = 0; i < pkt->mac_len; i++, p++)
+                       printf("%02x%c", *p, i==pkt->mac_len-1 ? ' ':':');
+       }
+       printf("\n");
+
+}
+
+main()
+{
+       struct ipulog_handle *h;
+       unsigned char* buf;
+       size_t len;
+       ulog_packet_msg_t *upkt;
+       
+       /* allocate a receive buffer */
+       buf = (unsigned char *) malloc(MYBUFSIZ);
+       
+       /* create ipulog handle */
+       h = ipulog_create_handle(ipulog_group2gmask(32));
+       if (!h)
+       {
+               /* if some error occurrs, print it to stderr */
+               ipulog_perror(NULL);
+               exit(1);
+       }
+
+       /* endless loop receiving packets and handling them over to
+        * handle_packet */
+       while(1)
+       {
+               len = ipulog_read(h, buf, BUFSIZ, 1);
+               upkt = ipulog_get_packet(buf);  
+               printf("got %d bytes\n", len);
+               handle_packet(upkt);
+       }
+       
+       /* just to give it a cleaner look */
+       ipulog_destroy_handle(h);
+
+}