ref: fe320116dae05e61481e75297f402f1af956c5d6
dir: /sys/src/9/ip/eipconvtest.c/
#include <u.h> #include <libc.h> enum { Isprefix= 16, }; uchar prefixvals[256] = { [0x00] 0 | Isprefix, [0x80] 1 | Isprefix, [0xC0] 2 | Isprefix, [0xE0] 3 | Isprefix, [0xF0] 4 | Isprefix, [0xF8] 5 | Isprefix, [0xFC] 6 | Isprefix, [0xFE] 7 | Isprefix, [0xFF] 8 | Isprefix, }; uchar v4prefix[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0, 0, 0, 0 }; void hnputl(void *p, ulong v) { uchar *a; a = p; a[0] = v>>24; a[1] = v>>16; a[2] = v>>8; a[3] = v; } int eipconv(va_list *arg, Fconv *f) { char buf[8*5]; static char *efmt = "%.2lux%.2lux%.2lux%.2lux%.2lux%.2lux"; static char *ifmt = "%d.%d.%d.%d"; uchar *p, ip[16]; ulong *lp; ushort s; int i, j, n, eln, eli; switch(f->chr) { case 'E': /* Ethernet address */ p = va_arg(*arg, uchar*); sprint(buf, efmt, p[0], p[1], p[2], p[3], p[4], p[5]); break; case 'I': /* Ip address */ p = va_arg(*arg, uchar*); common: if(memcmp(p, v4prefix, 12) == 0) sprint(buf, ifmt, p[12], p[13], p[14], p[15]); else { /* find longest elision */ eln = eli = -1; for(i = 0; i < 16; i += 2){ for(j = i; j < 16; j += 2) if(p[j] != 0 || p[j+1] != 0) break; if(j > i && j - i > eln){ eli = i; eln = j - i; } } /* print with possible elision */ n = 0; for(i = 0; i < 16; i += 2){ if(i == eli){ n += sprint(buf+n, "::"); i += eln; if(i >= 16) break; } else if(i != 0) n += sprint(buf+n, ":"); s = (p[i]<<8) + p[i+1]; n += sprint(buf+n, "%ux", s); } } break; case 'i': /* v6 address as 4 longs */ lp = va_arg(*arg, ulong*); for(i = 0; i < 4; i++) hnputl(ip+4*i, *lp++); p = ip; goto common; case 'V': /* v4 ip address */ p = va_arg(*arg, uchar*); sprint(buf, ifmt, p[0], p[1], p[2], p[3]); break; case 'M': /* ip mask */ p = va_arg(*arg, uchar*); /* look for a prefix mask */ for(i = 0; i < 16; i++) if(p[i] != 0xff) break; if(i < 16){ if((prefixvals[p[i]] & Isprefix) == 0) goto common; for(j = i+1; j < 16; j++) if(p[j] != 0) goto common; n = 8*i + (prefixvals[p[i]] & ~Isprefix); } else n = 8*16; /* got one, use /xx format */ sprint(buf, "/%d", n); break; default: strcpy(buf, "(eipconv)"); } strconv(buf, f); return sizeof(uchar*); } uchar testvec[11][16] = { { 0,0,0,0, 0,0,0,0, 0,0,0xff,0xff, 1,3,4,5, }, { 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, }, { 0xff,0xff,0x80,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, }, { 0xff,0xff,0xff,0xc0, 0,0,0,0, 0,0,0,0, 0,0,0,0, }, { 0xff,0xff,0xff,0xff, 0xe0,0,0,0, 0,0,0,0, 0,0,0,0, }, { 0xff,0xff,0xff,0xff, 0xff,0xf0,0,0, 0,0,0,0, 0,0,0,0, }, { 0xff,0xff,0xff,0xff, 0xff,0xff,0xf8,0, 0,0,0,0, 0,0,0,0, }, { 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff, }, { 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, }, { 0,0,0,0, 0,0x11,0,0, 0,0,0,0, 0,0,0,0, }, { 0,0,0,0x11, 0,0,0,0, 0,0,0,0, 0,0,0,0x12, }, }; void main(void) { int i; fmtinstall('I', eipconv); fmtinstall('M', eipconv); for(i = 0; i < 11; i++) print("%I\n%M\n", testvec[i], testvec[i]); exits(0); }