[PATCH v3] ss: Enclose IPv6 address in brackets

[Florian Lehner]

This updated patch adds support for RFC2732 IPv6 address format with
brackets for the tool ss.
It implements the suggestion by Phil Sutter to use a further value,
whether an address was resolved to a hostname.

Signed-off-by: Lehner Florian <d...@der-flo.net>
---
 include/utils.h | 10 +++++++---
 lib/utils.c     | 11 +++++++----
 misc/ss.c       | 20 +++++++++++++++-----
 3 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/include/utils.h b/include/utils.h
index 6080b96..ffacb49 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -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);
 }

-const char *format_host(int af, int len, const void *addr)
+const char *format_host_b(int af, int len, const void *addr, bool
*resolved)
 {
        static char buf[256];

-       return format_host_r(af, len, addr, buf, 256);
+       return format_host_rb(af, len, addr, buf, 256, resolved);
 }


diff --git a/misc/ss.c b/misc/ss.c
index 12763c9..d37bd1d 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -1046,20 +1046,30 @@ do_numeric:

 static void inet_addr_print(const inet_prefix *a, int port, unsigned
int ifindex)
 {
-       char buf[1024];
-       const char *ap = buf;
+       char b1[1024], b2[1024];
+       const char *ap = b1;
        int est_len = addr_width;
        const char *ifname = NULL;
+       bool resolved = false;

        if (a->family == AF_INET) {
                if (a->data[0] == 0) {
-                       buf[0] = '*';
-                       buf[1] = 0;
+                       b1[0] = '*';
+                       b1[1] = 0;
                } else {
                        ap = format_host(AF_INET, 4, a->data);
                }
        } else {
-               ap = format_host(a->family, 16, a->data);
+               if (a->family == AF_INET6) {
+                       ap = format_host_b(a->family, 16, a->data, &resolved);
+                       if (!resolved)
+                       {
+                               sprintf(b2, "[%s]", ap);
+                               ap = b2;
+                       }
+               } else {
+                       ap = format_host(a->family, 16, a->data);
+               }
                est_len = strlen(ap);
                if (est_len <= addr_width)
                        est_len = addr_width;
-- 
2.9.4