lib/inet_proto: Review inet_proto_{a2n,n2a}()

The original intent was to make sure strings written by those functions
are NUL-terminated at all times, though it was suggested to get rid of
the 15 char protocol name limit as well which this patch accomplishes.

In addition to that, simplify inet_proto_a2n() a bit: Use the error
checking in get_u8() to find out whether passed 'buf' contains a valid
decimal number instead of checking the first character's value manually.

Signed-off-by: Phil Sutter <phil@nwl.cc>
This commit is contained in:
Phil Sutter 2017-08-24 11:51:47 +02:00 committed by Stephen Hemminger
parent eab4507898
commit cfda500a7d

View File

@ -25,7 +25,7 @@
const char *inet_proto_n2a(int proto, char *buf, int len)
{
static char ncache[16];
static char *ncache;
static int icache = -1;
struct protoent *pe;
@ -34,9 +34,12 @@ const char *inet_proto_n2a(int proto, char *buf, int len)
pe = getprotobynumber(proto);
if (pe) {
if (icache != -1)
free(ncache);
icache = proto;
strncpy(ncache, pe->p_name, 16);
strncpy(buf, pe->p_name, len);
ncache = strdup(pe->p_name);
strncpy(buf, pe->p_name, len - 1);
buf[len - 1] = '\0';
return buf;
}
snprintf(buf, len, "ipproto-%d", proto);
@ -45,24 +48,23 @@ const char *inet_proto_n2a(int proto, char *buf, int len)
int inet_proto_a2n(const char *buf)
{
static char ncache[16];
static char *ncache;
static int icache = -1;
struct protoent *pe;
__u8 ret;
if (icache>=0 && strcmp(ncache, buf) == 0)
if (icache != -1 && strcmp(ncache, buf) == 0)
return icache;
if (buf[0] >= '0' && buf[0] <= '9') {
__u8 ret;
if (get_u8(&ret, buf, 10))
return -1;
if (!get_u8(&ret, buf, 10))
return ret;
}
pe = getprotobyname(buf);
if (pe) {
if (icache != -1)
free(ncache);
icache = pe->p_proto;
strncpy(ncache, pe->p_name, 16);
ncache = strdup(pe->p_name);
return pe->p_proto;
}
return -1;