/* sys/socket.h is necessary to compile when using netlink on older systems. */
# include <sys/socket.h>
# include <linux/netlink.h>
+#if HAVE_LINUX_INET_DIAG_H
# include <linux/inet_diag.h>
+#endif
# include <sys/socket.h>
# include <arpa/inet.h>
/* #endif KERNEL_LINUX */
#endif /* KERNEL_AIX */
#if KERNEL_LINUX
+#if HAVE_STRUCT_LINUX_INET_DIAG_REQ
struct nlreq {
struct nlmsghdr nlh;
struct inet_diag_req r;
};
+#endif
static const char *tcp_state[] =
{
static int port_collect_listening = 0;
static port_entry_t *port_list_head = NULL;
+#if KERNEL_LINUX
+#if HAVE_STRUCT_LINUX_INET_DIAG_REQ
+/* This depends on linux inet_diag_req because if this structure is missing,
+ * sequence_number is useless and we get a compilation warning.
+ */
+static uint32_t sequence_number = 0;
+#endif
+
+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];
/* If this entry was created while reading the files (ant not when handling
* the configuration) remove it now. */
if ((pe->flags & (PORT_COLLECT_LOCAL
- | PORT_COLLECT_REMOTE
- | PORT_IS_LISTENING)) == 0)
+ | PORT_COLLECT_REMOTE
+ | PORT_IS_LISTENING)) == 0)
{
port_entry_t *next = pe->next;
DEBUG ("tcpconns plugin: Removing temporary entry "
- "for listening port %"PRIu16, pe->port);
+ "for listening port %"PRIu16, pe->port);
if (prev == NULL)
- port_list_head = next;
+ port_list_head = next;
else
- prev->next = next;
+ prev->next = next;
sfree (pe);
pe = next;
memset (pe->count_remote, '\0', sizeof (pe->count_remote));
pe->flags &= ~PORT_IS_LISTENING;
+ prev = pe;
pe = pe->next;
}
} /* void conn_reset_port_entry */
} /* 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)
{
+#if HAVE_STRUCT_LINUX_INET_DIAG_REQ
int fd;
struct sockaddr_nl nladdr;
struct nlreq req;
struct iovec iov;
struct inet_diag_msg *r;
char buf[8192];
- static uint32_t sequence_number = 0;
+ /* 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)
- return (1);
+ {
+ 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;
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);
+ return (-1);
}
iov.iov_base = buf;
status = recvmsg(fd, (void *) &msg, /* flags = */ 0);
if (status < 0)
{
- if (errno == EINTR)
+ 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);
+ return (-1);
}
-
- if (status == 0)
+ 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)
+ if (h->nlmsg_seq != sequence_number)
{
- if (h->nlmsg_type == NLMSG_DONE)
- {
- close (fd);
- return (0);
- }
- else if (h->nlmsg_type == NLMSG_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);
+ 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);
+#else
+ return (1);
+#endif /* HAVE_STRUCT_LINUX_INET_DIAG_REQ */
} /* int conn_read_netlink */
static int conn_handle_line (char *buffer)
static int conn_read (void)
{
- int errors_num = 0;
+ int status;
conn_reset_port_entry ();
- /* Try to use netlink for getting this data, it is _much_ faster on systems
- * with a large amount of connections. */
- if (conn_read_netlink () != 0)
+ if (linux_source == SRC_NETLINK)
+ {
+ status = conn_read_netlink ();
+ }
+ else if (linux_source == SRC_PROC)
{
+ 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)
- {
- conn_submit_all ();
+ if (errors_num < 2)
+ status = 0;
+ else
+ status = ENOENT;
}
- else
+ else /* if (linux_source == SRC_DUNNO) */
{
- ERROR ("tcpconns plugin: Neither /proc/net/tcp nor /proc/net/tcp6 "
- "could be read.");
- return (-1);
+ /* 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 */
/* #endif KERNEL_LINUX */
while (next != head)
{
/* Read the pcb pointed to by `next' into `inpcb' */
- kread ((u_long) next, &inpcb, sizeof (inpcb));
+ status = kread ((u_long) next, &inpcb, sizeof (inpcb));
+ if (status != 0)
+ return (-1);
/* Advance `next' */
next = (struct inpcb *)CIRCLEQ_NEXT (&inpcb, inp_queue);
continue;
#endif
- kread ((u_long) inpcb.inp_ppcb, &tcpcb, sizeof (tcpcb));
+ status = kread ((u_long) inpcb.inp_ppcb, &tcpcb, sizeof (tcpcb));
+ if (status != 0)
+ return (-1);
conn_handle_ports (ntohs(inpcb.inp_lport), ntohs(inpcb.inp_fport), tcpcb.t_state);
} /* while (next != head) */