+++ /dev/null
-/*
- * lib/nl.c Core Netlink Interface
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation version 2.1
- * of the License.
- *
- * Copyright (c) 2003-2006 Thomas Graf <tgraf@suug.ch>
- */
-
-/**
- * @defgroup nl Core Netlink API
- * @brief
- *
- * @par 1) Creating the netlink handle
- * @code
- * struct nl_handle *handle;
- *
- * // Allocate and initialize a new netlink handle
- * handle = nl_handle_new();
- *
- * // Are multiple handles being allocated? You have to provide a unique
- * // netlink process id and overwrite the default local process id.
- * nl_handle_set_pid(handle, MY_UNIQUE_PID);
- *
- * // Is this socket used for event processing? You need to disable sequence
- * // number checking in order to be able to receive messages not explicitely
- * // requested.
- * nl_disable_sequence_check(handle);
- *
- * // Use nl_handle_get_fd() to fetch the file description, for example to
- * // put a socket into non-blocking i/o mode.
- * fcntl(nl_handle_get_fd(handle), F_SETFL, O_NONBLOCK);
- * @endcode
- *
- * @par 2) Joining Groups
- * @code
- * // You may join/subscribe to as many groups as you want, don't forget
- * // to eventually disable sequence number checking. Note: Joining must
- * // be done before connecting/binding the socket.
- * nl_join_groups(handle, GROUP_ID1 | GROUP_ID2);
- * @endcode
- *
- * @par 3) Connecting the socket
- * @code
- * // Bind and connect the socket to a protocol, NETLINK_ROUTE in this example.
- * nl_connect(handle, NETLINK_ROUTE);
- * @endcode
- *
- * @par 4) Sending data
- * @code
- * // The most rudimentary method is to use nl_sendto() simply pushing
- * // a piece of data to the other netlink peer. This method is not
- * // recommended.
- * const char buf[] = { 0x01, 0x02, 0x03, 0x04 };
- * nl_sendto(handle, buf, sizeof(buf));
- *
- * // A more comfortable interface is nl_send() taking a pointer to
- * // a netlink message.
- * struct nl_msg *msg = my_msg_builder();
- * nl_send(handle, nlmsg_hdr(msg));
- *
- * // nl_sendmsg() provides additional control over the sendmsg() message
- * // header in order to allow more specific addressing of multiple peers etc.
- * struct msghdr hdr = { ... };
- * nl_sendmsg(handle, nlmsg_hdr(msg), &hdr);
- *
- * // You're probably too lazy to fill out the netlink pid, sequence number
- * // and message flags all the time. nl_send_auto_complete() automatically
- * // extends your message header as needed with an appropriate sequence
- * // number, the netlink pid stored in the netlink handle and the message
- * // flags NLM_F_REQUEST and NLM_F_ACK
- * nl_send_auto_complete(handle, nlmsg_hdr(msg));
- *
- * // Simple protocols don't require the complex message construction interface
- * // and may favour nl_send_simple() to easly send a bunch of payload
- * // encapsulated in a netlink message header.
- * nl_send_simple(handle, MY_MSG_TYPE, 0, buf, sizeof(buf));
- * @endcode
- *
- * @par 5) Receiving data
- * @code
- * // nl_recv() receives a single message allocating a buffer for the message
- * // content and gives back the pointer to you.
- * struct sockaddr_nl peer;
- * unsigned char *msg;
- * nl_recv(handle, &peer, &msg);
- *
- * // nl_recvmsgs() receives a bunch of messages until the callback system
- * // orders it to state, usually after receving a compolete multi part
- * // message series.
- * nl_recvmsgs(handle, my_callback_configuration);
- *
- * // nl_recvmsgs_def() acts just like nl_recvmsg() but uses the callback
- * // configuration stored in the handle.
- * nl_recvmsgs_def(handle);
- *
- * // In case you want to wait for the ACK to be recieved that you requested
- * // with your latest message, you can call nl_wait_for_ack()
- * nl_wait_for_ack(handle);
- * @endcode
- *
- * @par 6) Cleaning up
- * @code
- * // Close the socket first to release kernel memory
- * nl_close(handle);
- *
- * // Finally destroy the netlink handle
- * nl_handle_destroy(handle);
- * @endcode
- *
- * @{
- */
-
-#include <netlink-local.h>
-#include <netlink/netlink.h>
-#include <netlink/utils.h>
-#include <netlink/handlers.h>
-#include <netlink/msg.h>
-#include <netlink/attr.h>
-
-/**
- * @name Handle Management
- * @{
- */
-
-/**
- * Allocate and initialize new non-default netlink handle.
- * @arg kind Kind of callback handler to use per default.
- *
- * Allocates and initializes a new netlink handle, the netlink process id
- * is set to the local process id which may conflict if multiple handles
- * are created, therefore you may have to overwrite it using
- * nl_handle_set_pid(). The initial sequence number is initialized to the
- * current UNIX time.
- *
- * @return Newly allocated netlink handle or NULL.
- */
-struct nl_handle *nl_handle_alloc_nondefault(enum nl_cb_kind kind)
-{
- struct nl_handle *handle;
-
- handle = calloc(1, sizeof(*handle));
- if (!handle)
- goto errout;
-
- handle->h_cb = nl_cb_new(kind);
- if (!handle->h_cb)
- goto errout;
-
- handle->h_local.nl_family = AF_NETLINK;
- handle->h_peer.nl_family = AF_NETLINK;
- handle->h_local.nl_pid = getpid();
- handle->h_seq_expect = handle->h_seq_next = time(0);
-
- return handle;
-errout:
- nl_handle_destroy(handle);
- nl_errno(ENOMEM);
- return NULL;
-}
-
-/**
- * Allocate and initialize new netlink handle.
- *
- * Allocates and initializes a new netlink handle, the netlink process id
- * is set to the local process id which may conflict if multiple handles
- * are created, therefore you may have to overwrite it using
- * nl_handle_set_pid(). The initial sequence number is initialized to the
- * current UNIX time. The default callback (NL_CB_DEFAULT) handlers are
- * being used.
- *
- * @return Newly allocated netlink handle or NULL.
- */
-struct nl_handle *nl_handle_alloc(void)
-{
- return nl_handle_alloc_nondefault(NL_CB_DEFAULT);
-}
-
-/**
- * Destroy netlink handle.
- * @arg handle Netlink handle.
- */
-void nl_handle_destroy(struct nl_handle *handle)
-{
- if (!handle)
- return;
-
- nl_cb_destroy(handle->h_cb);
- free(handle);
-}
-
-/** @} */
-
-/**
- * @name Utilities
- * @{
- */
-
-/**
- * Set socket buffer size of netlink handle.
- * @arg handle Netlink handle.
- * @arg rxbuf New receive socket buffer size in bytes.
- * @arg txbuf New transmit socket buffer size in bytes.
- *
- * Sets the socket buffer size of a netlink handle to the specified
- * values \c rxbuf and \c txbuf. Providing a value of \c 0 assumes a
- * good default value.
- *
- * @note It is not required to call this function prior to nl_connect().
- * @return 0 on sucess or a negative error code.
- */
-int nl_set_buffer_size(struct nl_handle *handle, int rxbuf, int txbuf)
-{
- int err;
-
- if (rxbuf <= 0)
- rxbuf = 32768;
-
- if (txbuf <= 0)
- txbuf = 32768;
-
- err = setsockopt(handle->h_fd, SOL_SOCKET, SO_SNDBUF,
- &txbuf, sizeof(txbuf));
- if (err < 0)
- return nl_error(errno, "setsockopt(SO_SNDBUF) failed");
-
- err = setsockopt(handle->h_fd, SOL_SOCKET, SO_RCVBUF,
- &rxbuf, sizeof(rxbuf));
- if (err < 0)
- return nl_error(errno, "setsockopt(SO_RCVBUF) failed");
-
- handle->h_flags |= NL_SOCK_BUFSIZE_SET;
-
- return 0;
-}
-
-/**
- * Enable/disable credential passing on netlink handle.
- * @arg handle Netlink handle
- * @arg state New state (0 - disabled, 1 - enabled)
- */
-int nl_set_passcred(struct nl_handle *handle, int state)
-{
- int err;
-
- err = setsockopt(handle->h_fd, SOL_SOCKET, SO_PASSCRED,
- &state, sizeof(state));
- if (err < 0)
- return nl_error(errno, "setsockopt(SO_PASSCRED) failed");
-
- if (state)
- handle->h_flags |= NL_SOCK_PASSCRED;
- else
- handle->h_flags &= ~NL_SOCK_PASSCRED;
-
- return 0;
-}
-
-/**
- * Join multicast groups.
- * @arg handle Netlink handle.
- * @arg groups Bitmask of groups to join.
- *
- * @note Joining of groups must be done prior to connecting/binding
- * the socket (nl_connect()).
- */
-void nl_join_groups(struct nl_handle *handle, int groups)
-{
- handle->h_local.nl_groups |= groups;
-}
-
-#ifndef SOL_NETLINK
-#define SOL_NETLINK 270
-#endif
-
-int nl_join_group(struct nl_handle *handle, int group)
-{
- int err;
-
- err = setsockopt(handle->h_fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP,
- &group, sizeof(group));
- if (err < 0)
- return nl_error(errno, "setsockopt(NETLINK_ADD_MEMBERSHIP) "
- "failed");
-
- return 0;
-}
-
-static int noop_seq_check(struct nl_msg *msg, void *arg)
-{
- return NL_PROCEED;
-}
-
-/**
- * Disable sequence number checking.
- * @arg handle Netlink handle.
- *
- * Disables checking of sequence numbers on the netlink handle. This is
- * required to allow messages to be processed which were not requested by
- * a preceding request message, e.g. netlink events.
- */
-void nl_disable_sequence_check(struct nl_handle *handle)
-{
- nl_cb_set(nl_handle_get_cb(handle), NL_CB_SEQ_CHECK,
- NL_CB_CUSTOM, noop_seq_check, NULL);
-}
-
-/** @} */
-
-/**
- * @name Acccess Functions
- * @{
- */
-
-/**
- * Get netlink process identifier of netlink handle.
- * @arg handle Netlink handle.
- * @return Netlink process identifier.
- */
-pid_t nl_handle_get_pid(struct nl_handle *handle)
-{
- return handle->h_local.nl_pid;
-}
-
-/**
- * Set netlink process identifier of netlink handle.
- * @arg handle Netlink handle.
- * @arg pid New netlink process identifier.
- */
-void nl_handle_set_pid(struct nl_handle *handle, pid_t pid)
-{
- handle->h_local.nl_pid = pid;
-}
-
-/**
- * Get netlink process identifier of peer from netlink handle.
- * @arg handle Netlink handle.
- * @return Netlink process identifier.
- */
-pid_t nl_handle_get_peer_pid(struct nl_handle *handle)
-{
- return handle->h_peer.nl_pid;
-}
-
-/**
- * Set netlink process identifier of peer in netlink handle.
- * @arg handle Netlink handle.
- * @arg pid New netlink process identifier.
- */
-void nl_handle_set_peer_pid(struct nl_handle *handle, pid_t pid)
-{
- handle->h_peer.nl_pid = pid;
-}
-
-/**
- * Get file descriptor of netlink handle.
- * @arg handle Netlink handle.
- * @return File descriptor of netlink socket or -1 if not connected.
- */
-int nl_handle_get_fd(struct nl_handle *handle)
-{
- return handle->h_fd;
-}
-
-/**
- * Get local netlink address of netlink handle.
- * @arg handle Netlink handle.
- * @return Local netlink address.
- */
-struct sockaddr_nl *nl_handle_get_local_addr(struct nl_handle *handle)
-{
- return &handle->h_local;
-}
-
-/**
- * Get peer netlink address of netlink handle.
- * @arg handle Netlink handle.
- * @note The peer address is undefined while the socket is unconnected.
- * @return Netlink address of the peer.
- */
-struct sockaddr_nl *nl_handle_get_peer_addr(struct nl_handle *handle)
-{
- return &handle->h_peer;
-}
-
-/**
- * Get callback configuration of netlink handle.
- * @arg handle Netlink handle.
- * @return Currently active callback configuration or NULL if not available.
- */
-struct nl_cb *nl_handle_get_cb(struct nl_handle *handle)
-{
- return handle->h_cb;
-}
-
-/** @} */
-
-/**
- * @name Connection Management
- * @{
- */
-
-/**
- * Create and connect netlink socket.
- * @arg handle Netlink handle.
- * @arg protocol Netlink protocol to use.
- *
- * Creates a netlink socket using the specified protocol, binds the socket
- * and issues a connection attempt.
- *
- * @return 0 on success or a negative error code.
- */
-int nl_connect(struct nl_handle *handle, int protocol)
-{
- int err;
- socklen_t addrlen;
-
- handle->h_fd = socket(AF_NETLINK, SOCK_RAW, protocol);
- if (handle->h_fd < 0)
- return nl_error(1, "socket(AF_NETLINK, ...) failed");
-
- if (!(handle->h_flags & NL_SOCK_BUFSIZE_SET)) {
- err = nl_set_buffer_size(handle, 0, 0);
- if (err < 0)
- return err;
- }
-
- err = bind(handle->h_fd, (struct sockaddr*) &handle->h_local,
- sizeof(handle->h_local));
- if (err < 0)
- return nl_error(1, "bind() failed");
-
- addrlen = sizeof(handle->h_local);
- err = getsockname(handle->h_fd, (struct sockaddr *) &handle->h_local,
- &addrlen);
- if (err < 0)
- return nl_error(1, "getsockname failed");
-
- if (addrlen != sizeof(handle->h_local))
- return nl_error(EADDRNOTAVAIL, "Invalid address length");
-
- if (handle->h_local.nl_family != AF_NETLINK)
- return nl_error(EPFNOSUPPORT, "Address format not supported");
-
- handle->h_proto = protocol;
-
- return 0;
-}
-
-/**
- * Close/Disconnect netlink socket.
- * @arg handle Netlink handle
- */
-void nl_close(struct nl_handle *handle)
-{
- if (handle->h_fd >= 0) {
- close(handle->h_fd);
- handle->h_fd = -1;
- }
-
- handle->h_proto = 0;
-}
-
-/** @} */
-
-/**
- * @name Send
- * @{
- */
-
-/**
- * Send raw data over netlink socket.
- * @arg handle Netlink handle.
- * @arg buf Data buffer.
- * @arg size Size of data buffer.
- * @return Number of characters written on success or a negative error code.
- */
-int nl_sendto(struct nl_handle *handle, void *buf, size_t size)
-{
- int ret;
-
- ret = sendto(handle->h_fd, buf, size, 0, (struct sockaddr *)
- &handle->h_peer, sizeof(handle->h_peer));
- if (ret < 0)
- return nl_errno(errno);
-
- return ret;
-}
-
-/**
- * Send netlink message with control over sendmsg() message header.
- * @arg handle Netlink handle.
- * @arg msg Netlink message to be sent.
- * @arg hdr Sendmsg() message header.
- * @return Number of characters sent on sucess or a negative error code.
- */
-int nl_sendmsg(struct nl_handle *handle, struct nl_msg *msg, struct msghdr *hdr)
-{
- struct nl_cb *cb;
- int ret;
-
- struct iovec iov = {
- .iov_base = (void *) nlmsg_hdr(msg),
- .iov_len = nlmsg_hdr(msg)->nlmsg_len,
- };
-
- hdr->msg_iov = &iov;
- hdr->msg_iovlen = 1;
-
- nlmsg_set_src(msg, &handle->h_local);
-
- cb = nl_handle_get_cb(handle);
- if (cb->cb_set[NL_CB_MSG_OUT])
- if (nl_cb_call(cb, NL_CB_MSG_OUT, msg) != NL_PROCEED)
- return 0;
-
- ret = sendmsg(handle->h_fd, hdr, 0);
- if (ret < 0)
- return nl_errno(errno);
-
- return ret;
-}
-
-
-/**
- * Send netlink message.
- * @arg handle Netlink handle
- * @arg msg Netlink message to be sent.
- * @see nl_sendmsg()
- * @return Number of characters sent on success or a negative error code.
- */
-int nl_send(struct nl_handle *handle, struct nl_msg *msg)
-{
- struct sockaddr_nl *dst;
- struct ucred *creds;
-
- struct msghdr hdr = {
- .msg_name = (void *) &handle->h_peer,
- .msg_namelen = sizeof(struct sockaddr_nl),
- };
-
- /* Overwrite destination if specified in the message itself, defaults
- * to the peer address of the handle.
- */
- dst = nlmsg_get_dst(msg);
- if (dst->nl_family == AF_NETLINK)
- hdr.msg_name = dst;
-
- /* Add credentials if present. */
- creds = nlmsg_get_creds(msg);
- if (creds != NULL) {
- char buf[CMSG_SPACE(sizeof(struct ucred))];
- struct cmsghdr *cmsg;
-
- hdr.msg_control = buf;
- hdr.msg_controllen = sizeof(buf);
-
- cmsg = CMSG_FIRSTHDR(&hdr);
- cmsg->cmsg_level = SOL_SOCKET;
- cmsg->cmsg_type = SCM_CREDENTIALS;
- cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
- memcpy(CMSG_DATA(cmsg), creds, sizeof(struct ucred));
- }
-
- return nl_sendmsg(handle, msg, &hdr);
-}
-
-/**
- * Send netlink message and check & extend header values as needed.
- * @arg handle Netlink handle.
- * @arg msg Netlink message to be sent.
- *
- * Checks the netlink message \c nlh for completness and extends it
- * as required before sending it out. Checked fields include pid,
- * sequence nr, and flags.
- *
- * @see nl_send()
- * @return Number of characters sent or a negative error code.
- */
-int nl_send_auto_complete(struct nl_handle *handle, struct nl_msg *msg)
-{
- struct nlmsghdr *nlh;
-
- nlh = nlmsg_hdr(msg);
- if (nlh->nlmsg_pid == 0)
- nlh->nlmsg_pid = handle->h_local.nl_pid;
-
- if (nlh->nlmsg_seq == 0)
- nlh->nlmsg_seq = handle->h_seq_next++;
-
- nlh->nlmsg_flags |= (NLM_F_REQUEST | NLM_F_ACK);
-
- if (handle->h_cb->cb_send_ow)
- return handle->h_cb->cb_send_ow(handle, msg);
- else
- return nl_send(handle, msg);
-}
-
-/**
- * Send simple netlink message using nl_send_auto_complete()
- * @arg handle Netlink handle.
- * @arg type Netlink message type.
- * @arg flags Netlink message flags.
- * @arg buf Data buffer.
- * @arg size Size of data buffer.
- *
- * Builds a netlink message with the specified type and flags and
- * appends the specified data as payload to the message.
- *
- * @see nl_send_auto_complete()
- * @return Number of characters sent on success or a negative error code.
- */
-int nl_send_simple(struct nl_handle *handle, int type, int flags, void *buf,
- size_t size)
-{
- int err;
- struct nl_msg *msg;
- struct nlmsghdr nlh = {
- .nlmsg_len = nlmsg_msg_size(0),
- .nlmsg_type = type,
- .nlmsg_flags = flags,
- };
-
- msg = nlmsg_build(&nlh);
- if (!msg)
- return nl_errno(ENOMEM);
-
- if (buf && size)
- nlmsg_append(msg, buf, size, 1);
-
- err = nl_send_auto_complete(handle, msg);
- nlmsg_free(msg);
-
- return err;
-}
-
-/** @} */
-
-/**
- * @name Receive
- * @{
- */
-
-/**
- * Receive netlink message from netlink socket.
- * @arg handle Netlink handle.
- * @arg nla Destination pointer for peer's netlink address.
- * @arg buf Destination pointer for message content.
- * @arg creds Destination pointer for credentials.
- *
- * Receives a netlink message, allocates a buffer in \c *buf and
- * stores the message content. The peer's netlink address is stored
- * in \c *nla. The caller is responsible for freeing the buffer allocated
- * in \c *buf if a positive value is returned. Interruped system calls
- * are handled by repeating the read. The input buffer size is determined
- * by peeking before the actual read is done.
- *
- * A non-blocking sockets causes the function to return immediately if
- * no data is available.
- *
- * @return Number of octets read, 0 on EOF or a negative error code.
- */
-int nl_recv(struct nl_handle *handle, struct sockaddr_nl *nla,
- unsigned char **buf, struct ucred **creds)
-{
- int n;
- int flags = MSG_PEEK;
-
- struct iovec iov = {
- .iov_len = 4096,
- };
-
- struct msghdr msg = {
- .msg_name = (void *) nla,
- .msg_namelen = sizeof(sizeof(struct sockaddr_nl)),
- .msg_iov = &iov,
- .msg_iovlen = 1,
- .msg_control = NULL,
- .msg_controllen = 0,
- .msg_flags = 0,
- };
- struct cmsghdr *cmsg;
-
- iov.iov_base = *buf = calloc(1, iov.iov_len);
-
- if (handle->h_flags & NL_SOCK_PASSCRED) {
- msg.msg_controllen = CMSG_SPACE(sizeof(struct ucred));
- msg.msg_control = calloc(1, msg.msg_controllen);
- }
-retry:
-
- if ((n = recvmsg(handle->h_fd, &msg, flags)) <= 0) {
- if (!n)
- goto abort;
- else if (n < 0) {
- if (errno == EINTR)
- goto retry;
- else if (errno == EAGAIN)
- goto abort;
- else {
- free(msg.msg_control);
- free(*buf);
- return nl_error(errno, "recvmsg failed");
- }
- }
- }
-
- if (iov.iov_len < n) {
- /* Provided buffer is not long enough, enlarge it
- * and try again. */
- iov.iov_len *= 2;
- iov.iov_base = *buf = realloc(*buf, iov.iov_len);
- goto retry;
- } else if (msg.msg_flags & MSG_CTRUNC) {
- msg.msg_controllen *= 2;
- msg.msg_control = realloc(msg.msg_control, msg.msg_controllen);
- goto retry;
- } else if (flags != 0) {
- /* Buffer is big enough, do the actual reading */
- flags = 0;
- goto retry;
- }
-
- if (msg.msg_namelen != sizeof(struct sockaddr_nl)) {
- free(msg.msg_control);
- free(*buf);
- return nl_error(EADDRNOTAVAIL, "socket address size mismatch");
- }
-
- for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
- if (cmsg->cmsg_level == SOL_SOCKET &&
- cmsg->cmsg_type == SCM_CREDENTIALS) {
- *creds = calloc(1, sizeof(struct ucred));
- memcpy(*creds, CMSG_DATA(cmsg), sizeof(struct ucred));
- break;
- }
- }
-
- free(msg.msg_control);
- return n;
-
-abort:
- free(msg.msg_control);
- free(*buf);
- return 0;
-}
-
-
-/**
- * Receive a set of messages from a netlink socket.
- * @arg handle netlink handle
- * @arg cb set of callbacks to control the behaviour.
- *
- * Repeatedly calls nl_recv() and parses the messages as netlink
- * messages. Stops reading if one of the callbacks returns
- * NL_EXIT or nl_recv returns either 0 or a negative error code.
- *
- * A non-blocking sockets causes the function to return immediately if
- * no data is available.
- *
- * @return 0 on success or a negative error code from nl_recv().
- */
-int nl_recvmsgs(struct nl_handle *handle, struct nl_cb *cb)
-{
- int n, err = 0;
- unsigned char *buf = NULL;
- struct nlmsghdr *hdr;
- struct sockaddr_nl nla = {0};
- struct nl_msg *msg = NULL;
- struct ucred *creds = NULL;
-
-continue_reading:
- if (cb->cb_recv_ow)
- n = cb->cb_recv_ow(handle, &nla, &buf, &creds);
- else
- n = nl_recv(handle, &nla, &buf, &creds);
-
- if (n <= 0)
- return n;
-
- NL_DBG(3, "recvmsgs(%p): Read %d bytes\n", handle, n);
-
- hdr = (struct nlmsghdr *) buf;
- while (nlmsg_ok(hdr, n)) {
- NL_DBG(3, "recgmsgs(%p): Processing valid message...\n",
- handle);
-
- nlmsg_free(msg);
- msg = nlmsg_convert(hdr);
- if (!msg) {
- err = nl_errno(ENOMEM);
- goto out;
- }
-
- nlmsg_set_proto(msg, handle->h_proto);
- nlmsg_set_src(msg, &nla);
- if (creds)
- nlmsg_set_creds(msg, creds);
-
- /* Raw callback is the first, it gives the most control
- * to the user and he can do his very own parsing. */
- if (cb->cb_set[NL_CB_MSG_IN]) {
- err = nl_cb_call(cb, NL_CB_MSG_IN, msg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0)
- goto out;
- }
-
- /* Sequence number checking. The check may be done by
- * the user, otherwise a very simple check is applied
- * enforcing strict ordering */
- if (cb->cb_set[NL_CB_SEQ_CHECK]) {
- err = nl_cb_call(cb, NL_CB_SEQ_CHECK, msg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0)
- goto out;
- } else if (hdr->nlmsg_seq != handle->h_seq_expect) {
- if (cb->cb_set[NL_CB_INVALID]) {
- err = nl_cb_call(cb, NL_CB_INVALID, msg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0)
- goto out;
- } else
- goto out;
- }
-
- if (hdr->nlmsg_type == NLMSG_DONE ||
- hdr->nlmsg_type == NLMSG_ERROR ||
- hdr->nlmsg_type == NLMSG_NOOP ||
- hdr->nlmsg_type == NLMSG_OVERRUN) {
- /* We can't check for !NLM_F_MULTI since some netlink
- * users in the kernel are broken. */
- handle->h_seq_expect++;
- NL_DBG(3, "recvmsgs(%p): Increased expected " \
- "sequence number to %d\n",
- handle, handle->h_seq_expect);
- }
-
- /* Other side wishes to see an ack for this message */
- if (hdr->nlmsg_flags & NLM_F_ACK) {
- if (cb->cb_set[NL_CB_SEND_ACK]) {
- err = nl_cb_call(cb, NL_CB_SEND_ACK, msg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0)
- goto out;
- } else {
- /* FIXME: implement */
- }
- }
-
- /* messages terminates a multpart message, this is
- * usually the end of a message and therefore we slip
- * out of the loop by default. the user may overrule
- * this action by skipping this packet. */
- if (hdr->nlmsg_type == NLMSG_DONE) {
- if (cb->cb_set[NL_CB_FINISH]) {
- err = nl_cb_call(cb, NL_CB_FINISH, msg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0)
- goto out;
- }
- err = 0;
- goto out;
- }
-
- /* Message to be ignored, the default action is to
- * skip this message if no callback is specified. The
- * user may overrule this action by returning
- * NL_PROCEED. */
- else if (hdr->nlmsg_type == NLMSG_NOOP) {
- if (cb->cb_set[NL_CB_SKIPPED]) {
- err = nl_cb_call(cb, NL_CB_SKIPPED, msg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0)
- goto out;
- } else
- goto skip;
- }
-
- /* Data got lost, report back to user. The default action is to
- * quit parsing. The user may overrule this action by retuning
- * NL_SKIP or NL_PROCEED (dangerous) */
- else if (hdr->nlmsg_type == NLMSG_OVERRUN) {
- if (cb->cb_set[NL_CB_OVERRUN]) {
- err = nl_cb_call(cb, NL_CB_OVERRUN, msg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0)
- goto out;
- } else
- goto out;
- }
-
- /* Message carries a nlmsgerr */
- else if (hdr->nlmsg_type == NLMSG_ERROR) {
- struct nlmsgerr *e = nlmsg_data(hdr);
-
- if (hdr->nlmsg_len < nlmsg_msg_size(sizeof(*e))) {
- /* Truncated error message, the default action
- * is to stop parsing. The user may overrule
- * this action by returning NL_SKIP or
- * NL_PROCEED (dangerous) */
- if (cb->cb_set[NL_CB_INVALID]) {
- err = nl_cb_call(cb, NL_CB_INVALID,
- msg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0)
- goto out;
- } else
- goto out;
- } else if (e->error) {
- /* Error message reported back from kernel. */
- if (cb->cb_err) {
- err = cb->cb_err(&nla, e,
- cb->cb_err_arg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0) {
- nl_error(-e->error,
- "Netlink Error");
- err = e->error;
- goto out;
- }
- } else {
- nl_error(-e->error, "Netlink Error");
- err = e->error;
- goto out;
- }
- } else if (cb->cb_set[NL_CB_ACK]) {
- /* ACK */
- err = nl_cb_call(cb, NL_CB_ACK, msg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0)
- goto out;
- }
- } else {
- /* Valid message (not checking for MULTIPART bit to
- * get along with broken kernels. NL_SKIP has no
- * effect on this. */
- if (cb->cb_set[NL_CB_VALID]) {
- err = nl_cb_call(cb, NL_CB_VALID, msg);
- if (err == NL_SKIP)
- goto skip;
- else if (err == NL_EXIT || err < 0)
- goto out;
- }
- }
-skip:
- hdr = nlmsg_next(hdr, &n);
- }
-
- nlmsg_free(msg);
- free(buf);
- free(creds);
- buf = NULL;
- msg = NULL;
- creds = NULL;
-
- /* Multipart message not yet complete, continue reading */
- goto continue_reading;
-
-out:
- nlmsg_free(msg);
- free(buf);
- free(creds);
-
- return err;
-}
-
-/**
- * Receive a set of message from a netlink socket using handlers in nl_handle.
- * @arg handle netlink handle
- *
- * Calls nl_recvmsgs() with the handlers configured in the netlink handle.
- */
-int nl_recvmsgs_def(struct nl_handle *handle)
-{
- if (handle->h_cb->cb_recvmsgs_ow)
- return handle->h_cb->cb_recvmsgs_ow(handle, handle->h_cb);
- else
- return nl_recvmsgs(handle, handle->h_cb);
-}
-
-static int ack_wait_handler(struct nl_msg *msg, void *arg)
-{
- return NL_EXIT;
-}
-
-/**
- * Wait for ACK.
- * @arg handle netlink handle
- * @pre The netlink socket must be in blocking state.
- *
- * Waits until an ACK is received for the latest not yet acknowledged
- * netlink message.
- */
-int nl_wait_for_ack(struct nl_handle *handle)
-{
- int err;
- struct nl_cb *cb = nl_cb_clone(nl_handle_get_cb(handle));
-
- nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_wait_handler, NULL);
-
- err = nl_recvmsgs(handle, cb);
- nl_cb_destroy(cb);
-
- return err;
-}
-
-/** @} */
-
-/**
- * @name Netlink Family Translations
- * @{
- */
-
-static struct trans_tbl nlfamilies[] = {
- __ADD(NETLINK_ROUTE,route)
- __ADD(NETLINK_W1,w1)
- __ADD(NETLINK_USERSOCK,usersock)
- __ADD(NETLINK_FIREWALL,firewall)
- __ADD(NETLINK_INET_DIAG,inetdiag)
- __ADD(NETLINK_NFLOG,nflog)
- __ADD(NETLINK_XFRM,xfrm)
- __ADD(NETLINK_SELINUX,selinux)
- __ADD(NETLINK_ISCSI,iscsi)
- __ADD(NETLINK_AUDIT,audit)
- __ADD(NETLINK_FIB_LOOKUP,fib_lookup)
- __ADD(NETLINK_CONNECTOR,connector)
- __ADD(NETLINK_NETFILTER,netfilter)
- __ADD(NETLINK_IP6_FW,ip6_fw)
- __ADD(NETLINK_DNRTMSG,dnrtmsg)
- __ADD(NETLINK_KOBJECT_UEVENT,kobject_uevent)
- __ADD(NETLINK_GENERIC,generic)
-};
-
-/**
- * Convert netlink family to character string.
- * @arg family Netlink family.
- * @arg buf Destination buffer.
- * @arg size Size of destination buffer.
- *
- * Converts a netlink family to a character string and stores it in
- * the specified destination buffer.
- *
- * @return The destination buffer or the family encoded in hexidecimal
- * form if no match was found.
- */
-char * nl_nlfamily2str(int family, char *buf, size_t size)
-{
- return __type2str(family, buf, size, nlfamilies,
- ARRAY_SIZE(nlfamilies));
-}
-
-/**
- * Convert character string to netlink family.
- * @arg name Name of netlink family.
- *
- * Converts the provided character string specifying a netlink
- * family to the corresponding numeric value.
- *
- * @return Numeric netlink family or a negative value if no match was found.
- */
-int nl_str2nlfamily(const char *name)
-{
- return __str2type(name, nlfamilies, ARRAY_SIZE(nlfamilies));
-}
-
-/** @} */
-/** @} */
git://git.onelab.eu / libnl.git / blobdiff