PATCH: Problem translating domain to UTF8 form

[Wietse Venema]

Wietse Venema:
> Wietse Venema:
> > Sascha H?depohl:
> > > Hello!
> > > 
> > > i found this in maillog:
> > > 
> > > postfix/bounce[90860]: warning: midna_domain_to_utf8_create: Problem
> > > translating domain "mail.huedepohl.de" to UTF8 form: U_FILE_ACCESS_ERROR
> > > 
> > > i can't figure out what the problem ist.
> > > U_FILE_ACCESS_ERROR? Which file?
> > 
> > According to web search for "U_FILE_ACCESS_ERROR postfix" the ICU
> > library could not access some required file. The ICU library is not
> > part of Postfix.
> > 
> > Usually this is fixed by turning off chroot for the bounce daemon:
> > 
> > # postconf -F bounce/unix/chroot=n defer/unix/chroot=n trace/unix/chroot=n
> > # postfix reload
> 
> Fixed in Postfix 3.6, by calling some ICU library method before
> making the chroot() call.

I expect that this will be in the next stable release updates.

        Wietse

20200510

        Bitrot: avoid U_FILE_ACCESS_ERROR after chroot(), by
        initializing the ICU library before making the chroot()
        call. Files: util/midna_domain.[hc], global/mail_params.c.

diff --exclude=man --exclude=html --exclude=README_FILES --exclude=INSTALL 
--exclude=.indent.pro -r -ur 
/var/tmp/postfix-3.6-20200509-nonprod/src/global/mail_params.c 
./src/global/mail_params.c
--- /var/tmp/postfix-3.6-20200509-nonprod/src/global/mail_params.c      
2020-01-11 08:04:08.000000000 -0500
+++ ./src/global/mail_params.c  2020-05-11 09:45:42.000000000 -0400
@@ -871,6 +871,8 @@
     var_smtputf8_enable = 0;
 #else
     midna_domain_transitional = var_idna2003_compat;
+    if (var_smtputf8_enable)
+       midna_domain_pre_chroot();
 #endif
     util_utf8_enable = var_smtputf8_enable;
 
diff --exclude=man --exclude=html --exclude=README_FILES --exclude=INSTALL 
--exclude=.indent.pro -r -ur 
/var/tmp/postfix-3.6-20200509-nonprod/src/util/midna_domain.c 
./src/util/midna_domain.c
--- /var/tmp/postfix-3.6-20200509-nonprod/src/util/midna_domain.c       
2016-12-04 12:40:19.000000000 -0500
+++ ./src/util/midna_domain.c   2020-05-10 18:59:19.000000000 -0400
@@ -20,6 +20,8 @@
 /*
 /*     const char *midna_domain_suffix_to_utf8(
 /*     const char *name)
+/* AUXILIARY FUNCTIONS
+/*     void midna_domain_pre_chroot(void)
 /* DESCRIPTION
 /*     The functions in this module transform domain names from/to
 /*     ASCII and UTF-8 form. The result is cached to avoid repeated
@@ -52,6 +54,8 @@
 /*
 /*     midna_domain_transitional enables transitional conversion
 /*     between UTF8 and ASCII labels.
+/*
+/*     midna_domain_pre_chroot() does some pre-chroot initialization.
 /* SEE ALSO
 /*     http://unicode.org/reports/tr46/ Unicode IDNA Compatibility processing
 /*     msg(3) diagnostics interface
@@ -144,6 +148,22 @@
     }
 }
 
+/* midna_domain_pre_chroot - pre-chroot initialization */
+
+void    midna_domain_pre_chroot(void)
+{
+    UErrorCode error = U_ZERO_ERROR;
+    UIDNAInfo info = UIDNA_INFO_INITIALIZER;
+    UIDNA  *idna;
+
+    idna = uidna_openUTS46(midna_domain_transitional ? UIDNA_DEFAULT
+                          : UIDNA_NONTRANSITIONAL_TO_ASCII, &error);
+    if (U_FAILURE(error))
+       msg_warn("ICU library initialization failed: %s",
+                midna_domain_strerror(error, info.errors));
+    uidna_close(idna);
+}
+
 /* midna_domain_to_ascii_create - convert domain to ASCII */
 
 static void *midna_domain_to_ascii_create(const char *name, void 
*unused_context)
@@ -327,6 +347,7 @@
  /*
   * Test program - reads names from stdin, reports invalid names to stderr.
   */
+#include <unistd.h>
 #include <stdlib.h>
 #include <locale.h>
 
@@ -350,6 +371,11 @@
     /* msg_verbose = 1; */
     util_utf8_enable = 1;
 
+    if (geteuid() == 0) {
+       midna_domain_pre_chroot();
+       if (chroot(".") != 0)
+           msg_fatal("chroot(\".\"): %m");
+    }
     while (vstring_fgets_nonl(buffer, VSTREAM_IN)) {
        bp = STR(buffer);
        msg_info("> %s", bp);
diff --exclude=man --exclude=html --exclude=README_FILES --exclude=INSTALL 
--exclude=.indent.pro -r -ur 
/var/tmp/postfix-3.6-20200509-nonprod/src/util/midna_domain.h 
./src/util/midna_domain.h
--- /var/tmp/postfix-3.6-20200509-nonprod/src/util/midna_domain.h       
2016-11-05 18:38:56.000000000 -0400
+++ ./src/util/midna_domain.h   2020-05-11 09:46:32.000000000 -0400
@@ -18,6 +18,7 @@
 extern const char *midna_domain_to_utf8(const char *);
 extern const char *midna_domain_suffix_to_ascii(const char *);
 extern const char *midna_domain_suffix_to_utf8(const char *);
+extern void midna_domain_pre_chroot(void);
 
 extern int midna_domain_cache_size;
 extern int midna_domain_transitional;