On 08/01/2017 04:11 PM, Phil Sutter wrote: > On Tue, Aug 01, 2017 at 12:05:13PM +0200, Florian Lehner wrote: > [...] >> @@ -114,9 +114,13 @@ int addr64_n2a(__u64 addr, char *buff, size_t len); >> int af_bit_len(int af); >> int af_byte_len(int af); >> >> -const char *format_host_r(int af, int len, const void *addr, >> - char *buf, int buflen); >> -const char *format_host(int af, int lne, const void *addr); >> +const char *format_host_rb(int af, int len, const void *addr, >> + char *buf, int buflen, bool *resolved); >> +#define format_host_r(af, len, addr, buf, buflen) \ >> + format_host_rb(af, len, addr, buf, buflen, NULL) >> +const char *format_host_b(int af, int lne, const void *addr, bool >> *resolved); >> +#define format_host(af, lne, addr) \ >> + format_host_b(af, lne, addr, NULL) >> #define format_host_rta(af, rta) \ >> format_host(af, RTA_PAYLOAD(rta), RTA_DATA(rta)) >> const char *rt_addr_n2a_r(int af, int len, const void *addr, >> diff --git a/lib/utils.c b/lib/utils.c >> index 9aa3219..42c3bf5 100644 >> --- a/lib/utils.c >> +++ b/lib/utils.c >> @@ -898,8 +898,8 @@ static const char *resolve_address(const void *addr, >> int len, int af) >> } >> #endif >> >> -const char *format_host_r(int af, int len, const void *addr, >> - char *buf, int buflen) >> +const char *format_host_rb(int af, int len, const void *addr, >> + char *buf, int buflen, bool *resolved) >> { >> #ifdef RESOLVE_HOSTNAMES >> if (resolve_hosts) { >> @@ -909,17 +909,20 @@ const char *format_host_r(int af, int len, const >> void *addr, >> >> if (len > 0 && >> (n = resolve_address(addr, len, af)) != NULL) >> + { >> + *resolved = true; >> return n; >> + } >> } >> #endif >> return rt_addr_n2a_r(af, len, addr, buf, buflen); >> } > > Did you test that? I guess calling format_host() will lead to > dereference of a NULL pointer.
Yes, I did. And it just worked. David Laight suggested to use strchr(). Instead of changing stuff in lib/* I will try this.