d7d7e8e58e
- Created src/arp.h: ARP packet struct, cache entry struct, operation codes, lookup/request/resolve/receive API, sysfs registration - Created src/arp.c: ARP cache with 32 entries, request/reply handling, ARP response to incoming requests for our IP, sysfs /sys/arp/table with formatted IP/MAC/interface/state columns - Created apps/arp/arp.c: reads and displays /sys/arp/table - Kernel calls arp_init() at boot, registered sysfs 'arp' namespace - Tested: clean boot, ARP initialized, arp app in CPIO
31 lines
585 B
C
31 lines
585 B
C
/**
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* @file arp.c
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* @brief Display the ARP table.
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*
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* Reads the ARP cache from /sys/arp/table and displays it.
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*
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* Usage:
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* arp - Show the ARP table
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*/
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#include "syscalls.h"
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int main(void) {
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/* Open the ARP table sysfs file */
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int32_t fd = open("/sys/arp/table", 0);
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if (fd < 0) {
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puts("arp: failed to open /sys/arp/table\n");
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return 1;
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}
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/* Read and display contents */
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char buf[512];
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int32_t n;
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while ((n = read(fd, buf, sizeof(buf))) > 0) {
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write(1, buf, (uint32_t)n);
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}
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close(fd);
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return 0;
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}
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