lib: add `s` option to `pI4`/`pI6`/`pIA` printfrr

Adding an `s` after these printfrr specifiers replaces 0.0.0.0 / :: in
the output with a star (`*`).  This is primarily intended for use with
multicast, e.g. to print `(*,G)`.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

diff --git a/doc/developer/logging.rst b/doc/developer/logging.rst
index e6080468201eaaf3852feb642916f85d988f2d48..a51f51553f33bc290c75a4b91f1fca7b1112e2e5 100644 (file)
--- a/doc/developer/logging.rst
+++ b/doc/developer/logging.rst
@@ -123,10 +123,14 @@ Networking data types
 
    :frrfmtout:`1.2.3.4`
 
+   ``%pI4s``: :frrfmtout:`*` — print star instead of ``0.0.0.0`` (for multicast)
+
 .. frrfmt:: %pI6 (struct in6_addr *)
 
    :frrfmtout:`fe80::1234`
 
+   ``%pI6s``: :frrfmtout:`*` — print star instead of ``::`` (for multicast)
+
 .. frrfmt:: %pEA (struct ethaddr *)
 
    :frrfmtout:`01:23:45:67:89:ab`
@@ -135,6 +139,8 @@ Networking data types
 
    :frrfmtout:`1.2.3.4` / :frrfmtout:`fe80::1234`
 
+   ``%pIAs``: — print star instead of zero address (for multicast)
+
 .. frrfmt:: %pFX (struct prefix *)
 
    :frrfmtout:`1.2.3.0/24` / :frrfmtout:`fe80::1234/64`

diff --git a/lib/prefix.c b/lib/prefix.c
index d3e8a612ebd60f52b200ab8b8b575d11f7ac464d..4e9d41836dad0c2545d92eece996ef6fbc668095 100644 (file)
--- a/lib/prefix.c
+++ b/lib/prefix.c
@@ -1374,10 +1374,36 @@ static ssize_t printfrr_ia(struct fbuf *buf, struct printfrr_eargs *ea,
 {
        const struct ipaddr *ipa = ptr;
        char cbuf[INET6_ADDRSTRLEN];
+       bool use_star = false;
+
+       if (ea->fmt[0] == 's') {
+               use_star = true;
+               ea->fmt++;
+       }
 
        if (!ipa)
                return bputs(buf, "(null)");
 
+       if (use_star) {
+               struct in_addr zero4 = {};
+               struct in6_addr zero6 = {};
+
+               switch (ipa->ipa_type) {
+               case IPADDR_V4:
+                       if (!memcmp(&ipa->ip.addr, &zero4, sizeof(zero4)))
+                               return bputch(buf, '*');
+                       break;
+
+               case IPADDR_V6:
+                       if (!memcmp(&ipa->ip.addr, &zero6, sizeof(zero6)))
+                               return bputch(buf, '*');
+                       break;
+
+               default:
+                       break;
+               }
+       }
+
        ipaddr2str(ipa, cbuf, sizeof(cbuf));
        return bputs(buf, cbuf);
 }
@@ -1387,10 +1413,20 @@ static ssize_t printfrr_i4(struct fbuf *buf, struct printfrr_eargs *ea,
                           const void *ptr)
 {
        char cbuf[INET_ADDRSTRLEN];
+       bool use_star = false;
+       struct in_addr zero = {};
+
+       if (ea->fmt[0] == 's') {
+               use_star = true;
+               ea->fmt++;
+       }
 
        if (!ptr)
                return bputs(buf, "(null)");
 
+       if (use_star && !memcmp(ptr, &zero, sizeof(zero)))
+               return bputch(buf, '*');
+
        inet_ntop(AF_INET, ptr, cbuf, sizeof(cbuf));
        return bputs(buf, cbuf);
 }
@@ -1400,10 +1436,20 @@ static ssize_t printfrr_i6(struct fbuf *buf, struct printfrr_eargs *ea,
                           const void *ptr)
 {
        char cbuf[INET6_ADDRSTRLEN];
+       bool use_star = false;
+       struct in6_addr zero = {};
+
+       if (ea->fmt[0] == 's') {
+               use_star = true;
+               ea->fmt++;
+       }
 
        if (!ptr)
                return bputs(buf, "(null)");
 
+       if (use_star && !memcmp(ptr, &zero, sizeof(zero)))
+               return bputch(buf, '*');
+
        inet_ntop(AF_INET6, ptr, cbuf, sizeof(cbuf));
        return bputs(buf, cbuf);
 }

diff --git a/tests/lib/test_printfrr.c b/tests/lib/test_printfrr.c
index 76940775740b978f6971fce3758103ea855a000d..55aa9bdefc814bece172347644ca805135b2aaf5 100644 (file)
--- a/tests/lib/test_printfrr.c
+++ b/tests/lib/test_printfrr.c
@@ -186,6 +186,10 @@ int main(int argc, char **argv)
 
        test_va("VA [192.168.1.2 1234] --", "%pI4 %u", &ip, 1234);
 
+       inet_aton("0.0.0.0", &ip);
+       printchk("0.0.0.0", "%pI4", &ip);
+       printchk("*", "%pI4s", &ip);
+
        snprintfrr(buf, sizeof(buf), "test%s", "#1");
        csnprintfrr(buf, sizeof(buf), "test%s", "#2");
        assert(strcmp(buf, "test#1test#2") == 0);