/**************************************************************************** * net/icmp/icmp_input.c * Handling incoming ICMP input * * Copyright (C) 2007-2009, 2012, 2014-2015, 2017, 2019 Gregory Nutt. All * rights reserved. * Author: Gregory Nutt * * Adapted for NuttX from logic in uIP which also has a BSD-like license: * * Original author Adam Dunkels * Copyright () 2001-2003, Adam Dunkels. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote * products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #ifdef CONFIG_NET #include #include #include #include #include #include #include #include #include "devif/devif.h" #include "icmp/icmp.h" #include "utils/utils.h" #ifdef CONFIG_NET_ICMP /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #define IPv4BUF ((FAR struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)]) #define IPICMPBUF ((FAR struct icmp_iphdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)]) #define ICMPBUF ((FAR struct icmp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + IPv4_HDRLEN]) #define ICMPSIZE ((dev)->d_len - IPv4_HDRLEN) /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: icmp_datahandler * * Description: * Handle ICMP echo replies that are not accepted by the application. * * Input Parameters: * dev - Device instance only the input packet in d_buf, length = d_len; * conn - A pointer to the ICMP connection structure * buffer - A pointer to the buffer to be copied to the read-ahead * buffers * buflen - The number of bytes to copy to the read-ahead buffer. * * Returned Value: * The number of bytes actually buffered is returned. This will be either * zero or equal to buflen; partial packets are not buffered. * ****************************************************************************/ #ifdef CONFIG_NET_ICMP_SOCKET static uint16_t icmp_datahandler(FAR struct net_driver_s *dev, FAR struct icmp_conn_s *conn) { FAR struct ipv4_hdr_s *ipv4; struct sockaddr_in inaddr; FAR struct iob_s *iob; uint16_t offset; uint16_t buflen; uint8_t addrsize; int ret; /* Try to allocate on I/O buffer to start the chain without waiting (and * throttling as necessary). If we would have to wait, then drop the * packet. */ iob = iob_tryalloc(true); if (iob == NULL) { nerr("ERROR: Failed to create new I/O buffer chain\n"); goto drop; } /* Put the IPv4 address at the beginning of the read-ahead buffer */ ipv4 = IPv4BUF; inaddr.sin_family = AF_INET; inaddr.sin_port = 0; net_ipv4addr_copy(inaddr.sin_addr.s_addr, net_ip4addr_conv32(ipv4->srcipaddr)); /* Copy the src address info into the I/O buffer chain. We will not wait * for an I/O buffer to become available in this context. It there is * any failure to allocated, the entire I/O buffer chain will be discarded. */ addrsize = sizeof(struct sockaddr_in); ret = iob_trycopyin(iob, &addrsize, sizeof(uint8_t), 0, true); if (ret < 0) { /* On a failure, iob_trycopyin return a negated error value but does * not free any I/O buffers. */ nerr("ERROR: Failed to length to the I/O buffer chain: %d\n", ret); goto drop_with_chain; } offset = sizeof(uint8_t); ret = iob_trycopyin(iob, (FAR const uint8_t *)&inaddr, sizeof(struct sockaddr_in), offset, true); if (ret < 0) { /* On a failure, iob_trycopyin return a negated error value but does * not free any I/O buffers. */ nerr("ERROR: Failed to source address to the I/O buffer chain: %d\n", ret); goto drop_with_chain; } offset += sizeof(struct sockaddr_in); /* Copy the new ICMP reply into the I/O buffer chain (without waiting) */ buflen = ICMPSIZE; ret = iob_trycopyin(iob, (FAR uint8_t *)ICMPBUF, buflen, offset, true); if (ret < 0) { /* On a failure, iob_copyin return a negated error value but does * not free any I/O buffers. */ nerr("ERROR: Failed to add data to the I/O buffer chain: %d\n", ret); goto drop_with_chain; } /* Add the new I/O buffer chain to the tail of the read-ahead queue (again * without waiting). */ ret = iob_tryadd_queue(iob, &conn->readahead); if (ret < 0) { nerr("ERROR: Failed to queue the I/O buffer chain: %d\n", ret); goto drop_with_chain; } ninfo("Buffered %d bytes\n", buflen + addrsize + 1); dev->d_len = 0; return buflen; drop_with_chain: (void)iob_free_chain(iob); drop: dev->d_len = 0; return 0; } #endif /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: icmp_input * * Description: * Handle incoming ICMP input * * Input Parameters: * dev - The device driver structure containing the received ICMP * packet * * Returned Value: * None * * Assumptions: * The network is locked. * ****************************************************************************/ void icmp_input(FAR struct net_driver_s *dev) { FAR struct icmp_iphdr_s *ipicmp = IPICMPBUF; #ifdef CONFIG_NET_STATISTICS g_netstats.icmp.recv++; #endif /* ICMP echo (i.e., ping) processing. This is simple, we only change the * ICMP type from ECHO to ECHO_REPLY and adjust the ICMP checksum before * we return the packet. */ if (ipicmp->type == ICMP_ECHO_REQUEST) { /* Change the ICMP type */ ipicmp->type = ICMP_ECHO_REPLY; /* Swap IP addresses. */ net_ipv4addr_hdrcopy(ipicmp->destipaddr, ipicmp->srcipaddr); net_ipv4addr_hdrcopy(ipicmp->srcipaddr, &dev->d_ipaddr); /* Recalculate the ICMP checksum */ #if 0 /* The slow way... sum over the ICMP message */ ipicmp->icmpchksum = 0; ipicmp->icmpchksum = ~icmp_chksum(dev, (((uint16_t)ipicmp->len[0] << 8) | (uint16_t)ipicmp->len[1]) - IPv4_HDRLEN); if (ipicmp->icmpchksum == 0) { ipicmp->icmpchksum = 0xffff; } #else /* The quick way -- Since only the type has changed, just adjust the * checksum for the change of type */ if (ipicmp->icmpchksum >= HTONS(0xffff - (ICMP_ECHO_REQUEST << 8))) { ipicmp->icmpchksum += HTONS(ICMP_ECHO_REQUEST << 8) + 1; } else { ipicmp->icmpchksum += HTONS(ICMP_ECHO_REQUEST << 8); } #endif ninfo("Outgoing ICMP packet length: %d (%d)\n", dev->d_len, (ipicmp->len[0] << 8) | ipicmp->len[1]); #ifdef CONFIG_NET_STATISTICS g_netstats.icmp.sent++; g_netstats.ipv4.sent++; #endif } #ifdef CONFIG_NET_ICMP_SOCKET /* If an ICMP echo reply is received then there should also be * a thread waiting to received the echo response. */ else if (ipicmp->type == ICMP_ECHO_REPLY) { FAR struct icmp_conn_s *conn; uint16_t flags; /* Nothing consumed the ICMP reply. That might because this is * an old, invalid reply or simply because the ping application * has not yet put its poll or recv in place. */ /* Is there any connection that might expect this reply? */ conn = icmp_findconn(dev, ipicmp->id); if (conn == NULL) { /* No.. drop the packet */ goto drop; } flags = devif_conn_event(dev, conn, ICMP_ECHOREPLY, conn->list); if ((flags & ICMP_ECHOREPLY) != 0) { uint16_t nbuffered; /* Add the ICMP echo reply to the IPPROTO_ICMP socket read-ahead * buffer. */ nbuffered = icmp_datahandler(dev, conn); if (nbuffered == 0) { /* Could not buffer the data.. drop the packet */ goto drop; } } } #endif /* Otherwise the ICMP input was not processed */ else { nwarn("WARNING: Unknown ICMP cmd: %d\n", ipicmp->type); goto typeerr; } return; typeerr: #ifdef CONFIG_NET_STATISTICS g_netstats.icmp.typeerr++; #endif #ifdef CONFIG_NET_ICMP_SOCKET drop: #endif #ifdef CONFIG_NET_STATISTICS g_netstats.icmp.drop++; #endif dev->d_len = 0; } #endif /* CONFIG_NET_ICMP */ #endif /* CONFIG_NET */