X-Git-Url: http://git.onelab.eu/?p=libnl.git;a=blobdiff_plain;f=lib%2Fnl.c;fp=lib%2Fnl.c;h=0000000000000000000000000000000000000000;hp=600f93e3dc3f7169969e87b8d8ca6181e2a8c928;hb=332c8b7561dcac7ac95cc0d07328b1cb22d780a6;hpb=eabdd897b75ecc1fac5e255229a899126085e57a diff --git a/lib/nl.c b/lib/nl.c deleted file mode 100644 index 600f93e..0000000 --- a/lib/nl.c +++ /dev/null @@ -1,1080 +0,0 @@ -/* - * 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 - */ - -/** - * @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 -#include -#include -#include -#include -#include - -/** - * @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)); -} - -/** @} */ -/** @} */