diff options
| -rw-r--r-- | lib/doh.c | 10 |
1 files changed, 8 insertions, 2 deletions
@@ -432,8 +432,14 @@ static unsigned short get16bit(unsigned char *doh, int index) static unsigned int get32bit(unsigned char *doh, int index) { - return (doh[index] << 24) | (doh[index + 1] << 16) | - (doh[index + 2] << 8) | doh[index + 3]; + /* make clang and gcc optimize this to bswap by incrementing + the pointer first. */ + doh += index; + + /* avoid undefined behaviour by casting to unsigned before shifting + 24 bits, possibly into the sign bit. codegen is same, but + ub sanitizer won't be upset */ + return ( (unsigned)doh[0] << 24) | (doh[1] << 16) |(doh[2] << 8) | doh[3]; } static DOHcode store_a(unsigned char *doh, int index, struct dohentry *d) |