static int conn_read (void)
{
int status;
conn_reset_port_entry ();
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)
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 */
/* 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 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);
}
struct sockaddr_nl nladdr = {.nl_family = AF_NETLINK};
struct nlreq req = {
.nlh.nlmsg_len = sizeof(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 */
.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST,
.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. */
.nlh.nlmsg_seq = ++sequence_number,
.r.idiag_family = AF_INET,
.r.idiag_states = 0xfff,
.r.idiag_ext = 0};
struct iovec iov = {.iov_base = &req, .iov_len = sizeof(req)};
struct msghdr msg = {.msg_name = (void *)&nladdr,
.msg_namelen = sizeof(nladdr),
.msg_iov = &iov,
.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);
#else
return (1);
#endif /* HAVE_STRUCT_LINUX_INET_DIAG_REQ */
} /* int conn_read_netlink */
static int conn_handle_line(char *buffer) {
char *fields[32];
int fields_len;
char *endptr;
char *port_local_str;
char *port_remote_str;
uint16_t port_local;
uint16_t port_remote;
uint8_t state;
int buffer_len = strlen(buffer);
while ((buffer_len > 0) && (buffer[buffer_len - 1] < 32))
buffer[--buffer_len] = '\0';
if (buffer_len <= 0)
return (-1);
fields_len = strsplit(buffer, fields, STATIC_ARRAY_SIZE(fields));
if (fields_len < 12) {
DEBUG("tcpconns plugin: Got %i fields, expected at least 12.", fields_len);
return (-1);
}
port_local_str = strchr(fields[1], ':');
port_remote_str = strchr(fields[2], ':');
if ((port_local_str == NULL) || (port_remote_str == NULL))
return (-1);
port_local_str++;
port_remote_str++;
if ((*port_local_str == '\0') || (*port_remote_str == '\0'))
return (-1);
endptr = NULL;
port_local = (uint16_t)strtol(port_local_str, &endptr, 16);
if ((endptr == NULL) || (*endptr != '\0'))
return (-1);
endptr = NULL;
port_remote = (uint16_t)strtol(port_remote_str, &endptr, 16);
if ((endptr == NULL) || (*endptr != '\0'))
return (-1);
endptr = NULL;
state = (uint8_t)strtol(fields[3], &endptr, 16);
if ((endptr == NULL) || (*endptr != '\0'))
return (-1);
return (conn_handle_ports(port_local, port_remote, state));
} /* int conn_handle_line */
static int conn_read_file(const char *file) {
FILE *fh;
char buffer[1024];
fh = fopen(file, "r");
if (fh == NULL)
return (-1);
while (fgets(buffer, sizeof(buffer), fh) != NULL) {
conn_handle_line(buffer);
} /* while (fgets) */
fclose(fh);
return (0);
} /* int conn_read_file */
/* #endif KERNEL_LINUX */
#elif HAVE_SYSCTLBYNAME
/* #endif HAVE_SYSCTLBYNAME */
#elif HAVE_LIBKVM_NLIST
#endif /* HAVE_LIBKVM_NLIST */
static int conn_config(const char *key, const char *value) {
if (strcasecmp(key, "ListeningPorts") == 0) {
if (IS_TRUE(value))
port_collect_listening = 1;
else
port_collect_listening = 0;
} else if ((strcasecmp(key, "LocalPort") == 0) ||
(strcasecmp(key, "RemotePort") == 0)) {
port_entry_t *pe;
int port = atoi(value);
if ((port < 1) || (port > 65535)) {
ERROR("tcpconns plugin: Invalid port: %i", port);
return (1);
}
pe = conn_get_port_entry((uint16_t)port, 1 /* create */);
if (pe == NULL) {
ERROR("tcpconns plugin: conn_get_port_entry failed.");
return (1);
}
if (strcasecmp(key, "LocalPort") == 0)
pe->flags |= PORT_COLLECT_LOCAL;
else
pe->flags |= PORT_COLLECT_REMOTE;
} else if (strcasecmp(key, "AllPortsSummary") == 0) {
if (IS_TRUE(value))
port_collect_total = 1;
else
port_collect_total = 0;
} else {
return (-1);
}
return (0);
} /* int conn_config */
#if KERNEL_LINUX
static int conn_init(void) {
if (port_collect_total == 0 && port_list_head == NULL)
port_collect_listening = 1;
return (0);
} /* int conn_init */
static int conn_read(void) {
int status;
conn_reset_port_entry();
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)
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 */