From 75cb44bc90577c3487458564ca803163681319f1 Mon Sep 17 00:00:00 2001
From: Gerhard Rieger <gerhard@dest-unreach.org>
Date: Sat, 13 Aug 2022 16:53:11 +0200
Subject: [PATCH] Correction of getprotobynumber_r() variant detection (musl
 libc)

---
 CHANGES      | 4 ++++
 configure.ac | 6 +++---
 fdname.c     | 8 ++++++--
 filan.c      | 2 +-
 4 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/CHANGES b/CHANGES
index 195eb6a..716680c 100644
--- a/CHANGES
+++ b/CHANGES
@@ -43,6 +43,10 @@ Porting:
 	IP_ADD_SOURCE_MEMBERSHIP but not struct ip_mreq_source
 	Thanks to Justin Yackoski for sending a patch.
 
+	configure.ac's detection of getprotobynumber_r() variant did not
+	recognize if this function does not exist, e.g. on Musl libc.
+	Thanks to Alexander Kanavin and Baruch Siach for sending patches.
+
 Testing:
 	Unset SOCAT_MAIN_WAIT on informational Socat calls
 
diff --git a/configure.ac b/configure.ac
index d4acc9e..973a7f2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -137,13 +137,13 @@ AC_MSG_RESULT($sc_cv_have_prototype_hstrerror)
 # getprotobynumber_r() is not standardized
 AC_MSG_CHECKING(for getprotobynumber_r() variant)
 AC_CACHE_VAL(sc_cv_getprotobynumber_r,
-[AC_TRY_COMPILE([#include <stddef.h>
+[AC_TRY_LINK([#include <stddef.h>
 #include <netdb.h>],[getprotobynumber_r(1,NULL,NULL,1024,NULL);],
 [sc_cv_getprotobynumber_r=1; tmp_bynum_variant=Linux],
- [AC_TRY_COMPILE([#include <stddef.h>
+ [AC_TRY_LINK([#include <stddef.h>
  #include <netdb.h>],[getprotobynumber_r(1,NULL,NULL,1024);],
  [sc_cv_getprotobynumber_r=2; tmp_bynum_variant=Solaris],
-  [AC_TRY_COMPILE([#include <stddef.h>
+  [AC_TRY_LINK([#include <stddef.h>
   #include <netdb.h>],[getprotobynumber_r(1,NULL,NULL);],
   [sc_cv_getprotobynumber_r=3; tmp_bynum_variant=AIX],
 
diff --git a/fdname.c b/fdname.c
index b076c3b..c7931a0 100644
--- a/fdname.c
+++ b/fdname.c
@@ -261,8 +261,12 @@ int sockname(int fd, FILE *outfile, char style) {
    }
    strncpy(protoname, protoentp->p_name, sizeof(protoname));
 #elif HAVE_GETPROTOBYNUMBER_R==2 /* Solaris */
-   protoentp = getprotobynumber(proto);
-   strncpy(protoname, protoentp->p_name, sizeof(protoname));
+   {
+#     define FILAN_GETPROTOBYNUMBER_R_BUFLEN 1024
+      char buffer[FILAN_GETPROTOBYNUMBER_R_BUFLEN];
+      protoentp = getprotobynumber_r(proto, &protoent, buffer, FILAN_GETPROTOBYNUMBER_R_BUFLEN);
+      strncpy(protoname, protoentp->p_name, sizeof(protoname));
+   }
 #elif HAVE_GETPROTOBYNUMBER_R==3 /* AIX */
    {
       struct protoent_data proto_data;
diff --git a/filan.c b/filan.c
index a733a0a..6403b45 100644
--- a/filan.c
+++ b/filan.c
@@ -917,7 +917,7 @@ int tcpan2(int fd, FILE *outfile) {
 	     fd, &tcpinfo, sizeof(tcpinfo), strerror(errno));
       return -1;
    }
-   fprintf(outfile, "%s={%u}\t", "TCPI_STATE", 		tcpinfo.tcpi_state);
+   fprintf(outfile, "%s={%u}\t", "TCPI_STATE",		tcpinfo.tcpi_state);
 #if 0  /* on BSD these components are prefixed with __ - I get tired... */
    fprintf(outfile, "%s={%u}\t", "TCPI_CA_STATE", 	tcpinfo.tcpi_ca_state);
    fprintf(outfile, "%s={%u}\t", "TCPI_RETRANSMITS", 	tcpinfo.tcpi_retransmits);