From 0b44a0315b47dd8eced9f3b7f31580cf14bbfc01 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sat, 12 Feb 2011 00:22:29 -0500 Subject: initial check-in, version 0.5.0 --- src/network/dn_expand.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 src/network/dn_expand.c (limited to 'src/network/dn_expand.c') diff --git a/src/network/dn_expand.c b/src/network/dn_expand.c new file mode 100644 index 00000000..01b449bb --- /dev/null +++ b/src/network/dn_expand.c @@ -0,0 +1,28 @@ +#include +#include + +#define BITOP(a,b,op) \ + ((a)[(size_t)(b)/(8*sizeof *(a))] op (size_t)1<<((size_t)(b)%(8*sizeof *(a)))) + +int dn_expand(unsigned char *b, unsigned char *pz, unsigned char *p, unsigned char *s, int outlen) +{ + /* Remember jump destinations to detect loops and abort */ + size_t seen[512/8/sizeof(size_t)] = { 0 }; + unsigned char *sz = s + outlen; + if (pz-b > 512) return -1; + for (;;) { + if (p>=pz) return -1; + else if (*p&0xc0) { + int j = (p[0]&1) | p[1]; + if (BITOP(seen, j, &)) return -1; + BITOP(seen, j, |=); + p = b + j; + } else if (*p) { + if (p+*p+1>=pz || s+*p>=sz) return -1; + memcpy(s, p+1, *p); + s += *p+1; + p += *p+1; + s[-1] = *p ? '.' : 0; + } else return 0; + } +} -- cgit v1.2.1