Exemple #1
0
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 */
Exemple #2
0
/* 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 */