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Diffstat (limited to 'nuttx/net/arp/uip_arptab.c')
-rw-r--r-- | nuttx/net/arp/uip_arptab.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/nuttx/net/arp/uip_arptab.c b/nuttx/net/arp/uip_arptab.c new file mode 100644 index 000000000..96a0f19b5 --- /dev/null +++ b/nuttx/net/arp/uip_arptab.c @@ -0,0 +1,260 @@ +/**************************************************************************** + * net/arp/uip_arptab.c + * Implementation of the ARP Address Resolution Protocol. + * + * Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Based originally on uIP which also has a BSD style license: + * + * Author: Adam Dunkels <adam@dunkels.com> + * Copyright (c) 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 <nuttx/config.h> +#ifdef CONFIG_NET + +#include <sys/ioctl.h> +#include <stdint.h> +#include <string.h> +#include <debug.h> + +#include <netinet/in.h> + +#include <net/ethernet.h> +#include <nuttx/net/uip/uipopt.h> +#include <nuttx/net/uip/uip-arch.h> +#include <nuttx/net/uip/uip-arp.h> + +#ifdef CONFIG_NET_ARP + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/* The table of known address mappings */ + +static struct arp_entry g_arptable[CONFIG_NET_ARPTAB_SIZE]; +static uint8_t g_arptime; + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: uip_arp_init + * + * Description: + * Initialize the ARP module. This function must be called before any of + * the other ARP functions. + * + ****************************************************************************/ + +void uip_arp_init(void) +{ + int i; + for (i = 0; i < CONFIG_NET_ARPTAB_SIZE; ++i) + { + memset(&g_arptable[i].at_ipaddr, 0, sizeof(in_addr_t)); + } +} + +/**************************************************************************** + * Name: uip_arp_timer + * + * Description: + * This function performs periodic timer processing in the ARP module + * and should be called at regular intervals. The recommended interval + * is 10 seconds between the calls. It is responsible for flushing old + * entries in the ARP table. + * + ****************************************************************************/ + +void uip_arp_timer(void) +{ + struct arp_entry *tabptr; + int i; + + ++g_arptime; + for (i = 0; i < CONFIG_NET_ARPTAB_SIZE; ++i) + { + tabptr = &g_arptable[i]; + if (tabptr->at_ipaddr != 0 && g_arptime - tabptr->at_time >= UIP_ARP_MAXAGE) + { + tabptr->at_ipaddr = 0; + } + } +} + +/**************************************************************************** + * Name: uip_arp_update + * + * Description: + * Add the IP/HW address mapping to the ARP table -OR- change the IP + * address of an existing association. + * + * Input parameters: + * pipaddr - Refers to an IP address uint16_t[2] + * ethaddr - Refers to a HW address uint8_t[IFHWADDRLEN] + * + * Assumptions + * Interrupts are disabled + * + ****************************************************************************/ + +void uip_arp_update(uint16_t *pipaddr, uint8_t *ethaddr) +{ + struct arp_entry *tabptr = NULL; + in_addr_t ipaddr = uip_ip4addr_conv(pipaddr); + int i; + + /* Walk through the ARP mapping table and try to find an entry to + * update. If none is found, the IP -> MAC address mapping is + * inserted in the ARP table. + */ + + for (i = 0; i < CONFIG_NET_ARPTAB_SIZE; ++i) + { + tabptr = &g_arptable[i]; + + /* Only check those entries that are actually in use. */ + + if (tabptr->at_ipaddr != 0) + { + /* Check if the source IP address of the incoming packet matches + * the IP address in this ARP table entry. + */ + + if (uip_ipaddr_cmp(ipaddr, tabptr->at_ipaddr)) + { + /* An old entry found, update this and return. */ + + memcpy(tabptr->at_ethaddr.ether_addr_octet, ethaddr, ETHER_ADDR_LEN); + tabptr->at_time = g_arptime; + return; + } + } + } + + /* If we get here, no existing ARP table entry was found, so we create one. */ + + /* First, we try to find an unused entry in the ARP table. */ + + for (i = 0; i < CONFIG_NET_ARPTAB_SIZE; ++i) + { + tabptr = &g_arptable[i]; + if (tabptr->at_ipaddr == 0) + { + break; + } + } + + /* If no unused entry is found, we try to find the oldest entry and + * throw it away. + */ + + if (i == CONFIG_NET_ARPTAB_SIZE) + { + uint8_t tmpage = 0; + int j = 0; + + for (i = 0; i < CONFIG_NET_ARPTAB_SIZE; ++i) + { + tabptr = &g_arptable[i]; + if (g_arptime - tabptr->at_time > tmpage) + { + tmpage = g_arptime - tabptr->at_time; + j = i; + } + } + + i = j; + tabptr = &g_arptable[i]; + } + + /* Now, i is the ARP table entry which we will fill with the new + * information. + */ + + tabptr->at_ipaddr = ipaddr; + memcpy(tabptr->at_ethaddr.ether_addr_octet, ethaddr, ETHER_ADDR_LEN); + tabptr->at_time = g_arptime; +} + +/**************************************************************************** + * Name: uip_arp_find + * + * Description: + * Find the ARP entry corresponding to this IP address. + * + * Input parameters: + * ipaddr - Refers to an IP address in network order + * + * Assumptions + * Interrupts are disabled; Returned value will become unstable when + * interrupts are re-enabled or if any other uIP APIs are called. + * + ****************************************************************************/ + +struct arp_entry *uip_arp_find(in_addr_t ipaddr) +{ + struct arp_entry *tabptr; + int i; + + for (i = 0; i < CONFIG_NET_ARPTAB_SIZE; ++i) + { + tabptr = &g_arptable[i]; + if (uip_ipaddr_cmp(ipaddr, tabptr->at_ipaddr)) + { + return tabptr; + } + } + + return NULL; +} + +#endif /* CONFIG_NET_ARP */ +#endif /* CONFIG_NET */ |