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authorDan Peebles <pumpkin@me.com>2017-10-30T16·25+0100
committerDan Peebles <pumpkin@me.com>2017-10-30T16·59+0100
commit4a4a009f78d7267d58a1dbd95f70f12ee3fe89f2 (patch)
tree4dd7f936847312e08d2082d8ec3f949cff6355f1 /src/libstore/sandbox-defaults.sb
parent6e5165b77370c76bfa39d4b55e9f83673f3bd466 (diff)
Allow optional localhost network access to sandboxed derivations
This will allow bind and connect to 127.0.0.1, which can reduce purity/
security (if you're running a vulnerable service on localhost) but is
also needed for a ton of test suites, so I'm leaving it turned off by
default but allowing certain derivations to turn it on as needed.

It also allows DNS resolution of arbitrary hostnames but I haven't found
a way to avoid that. In principle I'd just want to allow resolving
localhost but that doesn't seem to be possible.

I don't think this belongs under `build-use-sandbox = relaxed` because we
want it on Hydra and I don't think it's the end of the world.
Diffstat (limited to 'src/libstore/sandbox-defaults.sb')
-rw-r--r--src/libstore/sandbox-defaults.sb26
1 files changed, 24 insertions, 2 deletions
diff --git a/src/libstore/sandbox-defaults.sb b/src/libstore/sandbox-defaults.sb
index d63c8f813c9e..cf700c62c6fb 100644
--- a/src/libstore/sandbox-defaults.sb
+++ b/src/libstore/sandbox-defaults.sb
@@ -30,6 +30,29 @@
 ; Without this line clang cannot write to /dev/null, breaking some configure tests.
 (allow file-read-metadata (literal "/dev"))
 
+; Many packages like to do local networking in their test suites, but let's only
+; allow it if the package explicitly asks for it.
+(if (param "_ALLOW_LOCAL_NETWORKING")
+    (begin
+      (allow network* (local ip) (local tcp) (local udp))
+
+      ; Allow access to /etc/resolv.conf (which is a symlink to
+      ; /private/var/run/resolv.conf).
+      ; TODO: deduplicate with sandbox-network.sb
+      (allow file-read-metadata
+             (literal "/var")
+             (literal "/etc")
+             (literal "/etc/resolv.conf")
+             (literal "/private/etc/resolv.conf"))
+
+      (allow file-read*
+             (literal "/private/var/run/resolv.conf"))
+
+      ; Allow DNS lookups. This is even needed for localhost, which lots of tests rely on
+      (allow file-read-metadata (literal "/etc/hosts"))
+      (allow file-read*         (literal "/private/etc/hosts"))
+      (allow network-outbound (remote unix-socket (path-literal "/private/var/run/mDNSResponder")))))
+
 ; Standard devices.
 (allow file*
        (literal "/dev/null")
@@ -54,5 +77,4 @@
 (allow file-read-metadata
        (literal "/etc")
        (literal "/var")
-       (literal "/private/var/tmp")
-       )
+       (literal "/private/var/tmp"))