| /**************************************************************************** |
| * apps/netutils/netlib/netlib_getarptab.c |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. The |
| * ASF licenses this file to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance with the |
| * License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations |
| * under the License. |
| * |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Included Files |
| ****************************************************************************/ |
| |
| #include <nuttx/config.h> |
| |
| #include <sys/socket.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <string.h> |
| #include <errno.h> |
| |
| #include <netinet/arp.h> |
| #include <netpacket/netlink.h> |
| |
| #include "netutils/netlib.h" |
| |
| #if defined(CONFIG_NET_ARP) && defined(CONFIG_NETLINK_ROUTE) |
| |
| /**************************************************************************** |
| * Private Types |
| ****************************************************************************/ |
| |
| struct netlib_sendto_request_s |
| { |
| struct nlmsghdr hdr; |
| struct rtgenmsg gen; |
| }; |
| |
| struct netlib_recvfrom_response_s |
| { |
| struct nlmsghdr hdr; |
| struct ndmsg msg; |
| struct rtattr attr; |
| uint8_t data[1]; |
| }; |
| |
| #define SIZEOF_NETLIB_RECVFROM_RESPONSE_S(n) \ |
| (sizeof(struct netlib_recvfrom_response_s) + (n) - 1) |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Name: netlib_get_arptable |
| * |
| * Description: |
| * Attempt to read the entire ARP table into a buffer. |
| * |
| * Parameters: |
| * arptab - The location to store the copy of the ARP table |
| * nentries - The size of the provided 'arptab' in number of entries each |
| * of size sizeof(struct arpreq) |
| * |
| * Return: |
| * The number of ARP table entries read is returned on success; a negated |
| * errno value is returned on failure. |
| * |
| ****************************************************************************/ |
| |
| ssize_t netlib_get_arptable(FAR struct arpreq *arptab, |
| unsigned int nentries) |
| { |
| FAR struct netlib_recvfrom_response_s *resp; |
| struct netlib_sendto_request_s req; |
| struct sockaddr_nl addr; |
| static unsigned int seqno = 0; |
| unsigned int thiseq; |
| unsigned int allocsize; |
| ssize_t nsent; |
| ssize_t nrecvd; |
| ssize_t paysize; |
| ssize_t maxsize; |
| pid_t pid; |
| int fd; |
| int ret; |
| |
| /* Pre-allocate a buffer to hold the response */ |
| |
| maxsize = nentries * sizeof(struct arpreq); |
| allocsize = SIZEOF_NETLIB_RECVFROM_RESPONSE_S(maxsize); |
| resp = (FAR struct netlib_recvfrom_response_s *)malloc(allocsize); |
| if (resp == NULL) |
| { |
| fprintf(stderr, "ERROR: Failed to allocate response buffer\n"); |
| ret = -ENOMEM; |
| return EXIT_FAILURE; |
| } |
| |
| /* Create a NetLink socket with NETLINK_ROUTE protocol */ |
| |
| fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); |
| if (fd < 0) |
| { |
| int errcode = errno; |
| fprintf(stderr, "ERROR: socket() failed: %d\n", errcode); |
| ret = -errcode; |
| goto errout_with_resp; |
| } |
| |
| /* Bind the socket so that we can use send() and receive() */ |
| |
| pid = gettid(); |
| addr.nl_family = AF_NETLINK; |
| addr.nl_pad = 0; |
| addr.nl_pid = pid; |
| addr.nl_groups = 0; |
| |
| ret = bind(fd, (FAR const struct sockaddr *)&addr, |
| sizeof(struct sockaddr_nl)); |
| if (ret < 0) |
| { |
| int errcode = errno; |
| fprintf(stderr, "ERROR: bind() failed: %d\n", errcode); |
| ret = -errcode; |
| goto errout_with_socket; |
| } |
| |
| /* Initialize the request */ |
| |
| thiseq = ++seqno; |
| |
| memset(&req, 0, sizeof(req)); |
| req.hdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg)); |
| req.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP; |
| req.hdr.nlmsg_seq = thiseq; |
| req.hdr.nlmsg_type = RTM_GETNEIGH; |
| req.hdr.nlmsg_pid = pid; |
| req.gen.rtgen_family = AF_INET; |
| |
| nsent = send(fd, &req, req.hdr.nlmsg_len, 0); |
| if (nsent < 0) |
| { |
| int errcode = errno; |
| fprintf(stderr, "ERROR: send() failed: %d\n", errcode); |
| ret = -errcode; |
| goto errout_with_socket; |
| } |
| |
| /* Read the response */ |
| |
| nrecvd = recv(fd, resp, allocsize, 0); |
| if (nrecvd < 0) |
| { |
| int errcode = errno; |
| fprintf(stderr, "ERROR: recv() failed: %d\n", errcode); |
| ret = -errcode; |
| goto errout_with_socket; |
| } |
| |
| /* Verify the data and transfer the ARP table data to the caller */ |
| |
| if (resp->hdr.nlmsg_len < sizeof(struct nlmsghdr) || |
| resp->hdr.nlmsg_len > nrecvd) |
| { |
| fprintf(stderr, "ERROR: Bad message\n"); |
| ret = -EIO; |
| goto errout_with_socket; |
| } |
| |
| /* The sequence number in the response should match the sequence |
| * number in the request (since we created the socket, this should |
| * always be true). |
| */ |
| |
| if (resp->hdr.nlmsg_seq != thiseq) |
| { |
| fprintf(stderr, "ERROR: Bad sequence number in response\n"); |
| ret = -EIO; |
| goto errout_with_socket; |
| } |
| |
| /* Copy the ARP table data to the caller's buffer */ |
| |
| paysize = RTA_PAYLOAD(&resp->attr); |
| if (paysize > maxsize) |
| { |
| paysize = maxsize; |
| } |
| |
| memcpy(arptab, resp->data, paysize); |
| ret = paysize / sizeof(struct arpreq); |
| |
| errout_with_socket: |
| close(fd); |
| |
| errout_with_resp: |
| free(resp); |
| return ret; |
| } |
| |
| #endif /* CONFIG_NET_ARP && CONFIG_NETLINK_ROUTE */ |