arp.rar_arp_arp协议

/* arpprint - arpprint */ #include <conf.h> #include <kernel.h> #include <network.h> #include <io.h> #define HDR1 \ "Intf. IP address Physical Address HW Proto State TTL\n" #define HDR2 \ "----- --------------- ----------------- -- ----- -------- ---------\n" static int printone(int, struct arpentry *); /*------------------------------------------------------------------------ * arpprint - print the ARP table on descriptor fd *------------------------------------------------------------------------ */ int arpprint(int fd) { int i; write(fd, HDR1, strlen(HDR1)); write(fd, HDR2, strlen(HDR2)); for (i = 0; i<ARP_TSIZE; ++i) if (arptable[i].ae_state != AS_FREE) printone(fd, &arptable[i]); return OK; } char *index(const char *, char); /*------------------------------------------------------------------------ * printone - print one entry in the ARP table *------------------------------------------------------------------------ */ static int printone(int fd, struct arpentry *pae) { char line[128], *p; int i; sprintf(line, " %2d ", pae->ae_pni - &nif[0]); p = index(line, '\0'); for (i=0; i<pae->ae_prlen-1; ++i) { sprintf(p, "%u.", pae->ae_pra[i] & 0xff); p = index(p, '\0'); } sprintf(p, "%u", pae->ae_pra[i]); for (i=strlen(line); i<23; ++i) line[i] = ' '; p = &line[23]; for (i=0; i<pae->ae_hwlen-1; ++i) { sprintf(p, "%02x:", pae->ae_hwa[i] & 0xff); p = index(p, '\0'); } sprintf(p, "%02x %2d %04x %8s ", pae->ae_hwa[i] & 0xff, pae->ae_hwtype, pae->ae_prtype, (pae->ae_state == AS_RESOLVED) ? "RESOLVED" : "PENDING"); p = index(p, '\0'); if (pae->ae_ttl == ARP_INF) strcpy(p, "(permanent)\n"); else sprintf(p, "%8d s\n", pae->ae_ttl); return write(fd, line, strlen(line)); }