component/proftpd: allow dumping process

Unless compiled with --enable-devel=coredump, proftpd's mod_rlimit will
use a prctl(PR_SET_DUMPABLE, 0) syscall[1] which prevents us from
inspecting files open by this process[2]

We don't want to enable debug build and I did not find a way to disable
only this PR_SET_DUMPABLE flag setting.

[1] https://github.com/proftpd/proftpd/blob/v1.3.6/modules/mod_rlimit.c#L580-L583
[2] http://man7.org/linux/man-pages/man5/proc.5.html

component/proftpd/0001-mod_rlimit-don-t-change-PR_SET_DUMPABLE-flag.patch

+From ec7c3929df82855cc708f2074eb163590ecaeeaf Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?J=C3=A9rome=20Perrin?= <jerome@nexedi.com>
+Date: Wed, 23 May 2018 08:55:35 +0200
+Subject: [PATCH] mod_rlimit: don't change PR_SET_DUMPABLE flag
+
+In our case we don't really care if the process leaves a coredump and
+are interested in being able to inspect running processes for tests.
+---
+ modules/mod_rlimit.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/modules/mod_rlimit.c b/modules/mod_rlimit.c
+index 6788e4cee..2584260af 100644
+--- a/modules/mod_rlimit.c
++++ b/modules/mod_rlimit.c
+@@ -568,6 +568,8 @@ static int rlimit_set_core(int scope) {
+ #if !defined(PR_DEVEL_COREDUMP) && \
+     defined(HAVE_PRCTL) && \
+     defined(PR_SET_DUMPABLE)
++
++ #if 0 /* SlapOS patch: keep PR_SET_DUMPABLE for tests */
+   if (max == 0) {
+     /* Really, no core dumps please. On Linux, there are exceptions made
+      * even when setting RLIMIT_CORE = 0; see:
+@@ -582,6 +584,7 @@ static int rlimit_set_core(int scope) {
+         strerror(errno));
+     }
+   }
++#endif /* SlapOS patch */
+ #endif /* no --enable-devel=coredump and HAVE_PRCTL and PR_SET_DUMPABLE */
+ 
+   errno = xerrno;
+-- 
+2.11.0
+

component/proftpd/buildout.cfg

@@ -11,6 +11,7 @@ extends =
   ../curl/buildout.cfg
   ../libtool/buildout.cfg
   ../git/buildout.cfg
+  ../patch/buildout.cfg
 
 # proftpd server
 [proftpd-environment]
@@ -37,7 +38,10 @@ environment =
   install_group=${proftpd-grp:GROUP}
 cppflags=-I${zlib:location}/include -I${openssl:location}/include
 ldflags=-L${zlib:location}/lib -Wl,-rpath=${zlib:location}/lib -L${openssl:location}/lib -Wl,-rpath=${openssl:location}/lib
-
+patch-binary = ${patch:location}/bin/patch
+patch-options = -p1
+patches =
+  ${:_profile_base_location_}/0001-mod_rlimit-don-t-change-PR_SET_DUMPABLE-flag.patch#6e58a7a429ff96a51812dc9835e4c227
 
 # mod_auth_web: a proftpd module to authenticate users against an HTTP service
 [proftpd-mod_auth_web-repository]

[Jérome Perrin]

Of course, it makes proftpd "less secure", because this prevented user to trace the process to intercept tings like passwords, but in our case it should not be a problem because we have to trust user running the partition and root user.

https://unix.stackexchange.com/questions/55118/stracing-su-and-ssh-shows-the-password-is-this-a-security-flaw-or-am-i-missing