Not exactly. But, functionally close enough. I skipped commenting on strncpy to ignore the plethora of issues with lpd and focus on the question at hand.
D On Jun 5, 2013, at 7:20 AM, erik quanstrom <quans...@quanstro.net> wrote: > On Wed Jun 5 09:15:11 EDT 2013, don.bai...@gmail.com wrote: >> The first opportunity to write a nil byte should always be taken. >> Using sizeof only means that in corner cases memory disclosure may >> occur between where the nil should be and the end of the array. While >> this isn't a security critical app, it is still good coding practice. >> >> x = strlen(info.host) < sizeof info.host ? strlen() : sizeof ; >> info.host[x] = 0; > > let's start at the beginning. strncpy is not good coding practice. > and lpdaemon is not well written by today's standards. ☺ > > however, unless i'm missing something, the code has exactly that. > > /sys/src/cmd/lp/lpdaemon.c:297,310 > case 'H': > if (ap[1] == '\0') > strncpy(info.host, "unknown", NAMELEN); > else > strncpy(info.host, (const char *)&ap[1], NAMELEN); > info.host[NAMELEN] = '\0'; > break; > case 'P': > if (ap[1] == '\0') > strncpy(info.user, "unknown", NAMELEN); > else > strncpy(info.user, (const char *)&ap[1], NAMELEN); > info.user[NAMELEN] = '\0'; > break; > > - erik >
