* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Author:
- * Florian octo Forster <octo at verplant.org>
+ * Florian octo Forster <octo at collectd.org>
* Michael Stapelberg <michael+git at stapelberg.de>
**/
#endif
#if KERNEL_LINUX
+# include <asm/types.h>
+/* sys/socket.h is necessary to compile when using netlink on older systems. */
+# include <sys/socket.h>
+# include <linux/netlink.h>
+# include <linux/inet_diag.h>
+# include <sys/socket.h>
+# include <arpa/inet.h>
/* #endif KERNEL_LINUX */
#elif HAVE_SYSCTLBYNAME
#endif /* KERNEL_AIX */
#if KERNEL_LINUX
+struct nlreq {
+ struct nlmsghdr nlh;
+ struct inet_diag_req r;
+};
+
static const char *tcp_state[] =
{
"", /* 0 */
"CLOSED",
"LISTEN",
"SYN_SENT",
- "SYN_RCVD",
+ "SYN_RECV",
"ESTABLISHED",
"CLOSE_WAIT",
- "FIN_WAIT_1",
+ "FIN_WAIT1",
"CLOSING",
"LAST_ACK",
- "FIN_WAIT_2",
+ "FIN_WAIT2",
"TIME_WAIT"
};
static int port_collect_listening = 0;
static port_entry_t *port_list_head = NULL;
+#if KERNEL_LINUX
+static uint32_t sequence_number = 0;
+
+enum
+{
+ SRC_DUNNO,
+ SRC_NETLINK,
+ SRC_PROC
+} linux_source = SRC_DUNNO;
+#endif
+
static void conn_submit_port_entry (port_entry_t *pe)
{
value_t values[1];
} /* int conn_handle_ports */
#if KERNEL_LINUX
+/* Returns zero on success, less than zero on socket error and greater than
+ * zero on other errors. */
+static int conn_read_netlink (void)
+{
+ int fd;
+ struct sockaddr_nl nladdr;
+ struct nlreq req;
+ struct msghdr msg;
+ struct iovec iov;
+ struct inet_diag_msg *r;
+ char buf[8192];
+
+ /* If this fails, it's likely a permission problem. We'll fall back to
+ * reading this information from files below. */
+ fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_INET_DIAG);
+ if (fd < 0)
+ {
+ ERROR ("tcpconns plugin: conn_read_netlink: socket(AF_NETLINK, SOCK_RAW, "
+ "NETLINK_INET_DIAG) failed: %s",
+ sstrerror (errno, buf, sizeof (buf)));
+ return (-1);
+ }
+
+ memset(&nladdr, 0, sizeof(nladdr));
+ nladdr.nl_family = AF_NETLINK;
+
+ memset(&req, 0, sizeof(req));
+ req.nlh.nlmsg_len = sizeof(req);
+ req.nlh.nlmsg_type = TCPDIAG_GETSOCK;
+ /* NLM_F_ROOT: return the complete table instead of a single entry.
+ * NLM_F_MATCH: return all entries matching criteria (not implemented)
+ * NLM_F_REQUEST: must be set on all request messages */
+ req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
+ req.nlh.nlmsg_pid = 0;
+ /* The sequence_number is used to track our messages. Since netlink is not
+ * reliable, we don't want to end up with a corrupt or incomplete old
+ * message in case the system is/was out of memory. */
+ req.nlh.nlmsg_seq = ++sequence_number;
+ req.r.idiag_family = AF_INET;
+ req.r.idiag_states = 0xfff;
+ req.r.idiag_ext = 0;
+
+ memset(&iov, 0, sizeof(iov));
+ iov.iov_base = &req;
+ iov.iov_len = sizeof(req);
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_name = (void*)&nladdr;
+ msg.msg_namelen = sizeof(nladdr);
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+
+ if (sendmsg (fd, &msg, 0) < 0)
+ {
+ ERROR ("tcpconns plugin: conn_read_netlink: sendmsg(2) failed: %s",
+ sstrerror (errno, buf, sizeof (buf)));
+ close (fd);
+ return (-1);
+ }
+
+ iov.iov_base = buf;
+ iov.iov_len = sizeof(buf);
+
+ while (1)
+ {
+ int status;
+ struct nlmsghdr *h;
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_name = (void*)&nladdr;
+ msg.msg_namelen = sizeof(nladdr);
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+
+ status = recvmsg(fd, (void *) &msg, /* flags = */ 0);
+ if (status < 0)
+ {
+ if ((errno == EINTR) || (errno == EAGAIN))
+ continue;
+
+ ERROR ("tcpconns plugin: conn_read_netlink: recvmsg(2) failed: %s",
+ sstrerror (errno, buf, sizeof (buf)));
+ close (fd);
+ return (-1);
+ }
+ else if (status == 0)
+ {
+ close (fd);
+ DEBUG ("tcpconns plugin: conn_read_netlink: Unexpected zero-sized "
+ "reply from netlink socket.");
+ return (0);
+ }
+
+ h = (struct nlmsghdr*)buf;
+ while (NLMSG_OK(h, status))
+ {
+ if (h->nlmsg_seq != sequence_number)
+ {
+ h = NLMSG_NEXT(h, status);
+ continue;
+ }
+
+ if (h->nlmsg_type == NLMSG_DONE)
+ {
+ close (fd);
+ return (0);
+ }
+ else if (h->nlmsg_type == NLMSG_ERROR)
+ {
+ struct nlmsgerr *msg_error;
+
+ msg_error = NLMSG_DATA(h);
+ WARNING ("tcpconns plugin: conn_read_netlink: Received error %i.",
+ msg_error->error);
+
+ close (fd);
+ return (1);
+ }
+
+ r = NLMSG_DATA(h);
+
+ /* This code does not (need to) distinguish between IPv4 and IPv6. */
+ conn_handle_ports (ntohs(r->id.idiag_sport),
+ ntohs(r->id.idiag_dport),
+ r->idiag_state);
+
+ h = NLMSG_NEXT(h, status);
+ } /* while (NLMSG_OK) */
+ } /* while (1) */
+
+ /* Not reached because the while() loop above handles the exit condition. */
+ return (0);
+} /* int conn_read_netlink */
+
static int conn_handle_line (char *buffer)
{
char *fields[32];
static int conn_read (void)
{
- int errors_num = 0;
+ int status;
conn_reset_port_entry ();
- if (conn_read_file ("/proc/net/tcp") != 0)
- errors_num++;
- if (conn_read_file ("/proc/net/tcp6") != 0)
- errors_num++;
-
- if (errors_num < 2)
+ if (linux_source == SRC_NETLINK)
{
- conn_submit_all ();
+ status = conn_read_netlink ();
}
- else
+ else if (linux_source == SRC_PROC)
{
- ERROR ("tcpconns plugin: Neither /proc/net/tcp nor /proc/net/tcp6 "
- "coult be read.");
- return (-1);
+ int errors_num = 0;
+
+ if (conn_read_file ("/proc/net/tcp") != 0)
+ errors_num++;
+ if (conn_read_file ("/proc/net/tcp6") != 0)
+ errors_num++;
+
+ if (errors_num < 2)
+ status = 0;
+ else
+ status = ENOENT;
}
+ else /* if (linux_source == SRC_DUNNO) */
+ {
+ /* Try to use netlink for getting this data, it is _much_ faster on systems
+ * with a large amount of connections. */
+ status = conn_read_netlink ();
+ if (status == 0)
+ {
+ INFO ("tcpconns plugin: Reading from netlink succeeded. "
+ "Will use the netlink method from now on.");
+ linux_source = SRC_NETLINK;
+ }
+ else
+ {
+ INFO ("tcpconns plugin: Reading from netlink failed. "
+ "Will read from /proc from now on.");
+ linux_source = SRC_PROC;
+
+ /* return success here to avoid the "plugin failed" message. */
+ return (0);
+ }
+ }
+
+ if (status == 0)
+ conn_submit_all ();
+ else
+ return (status);
return (0);
} /* int conn_read */
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