[systemd-devel] [PATCH] core/socket: Add REMOTE_IP environment variable for Accept=true

[Shawn Landden]

Fix handling of abstract unix domain sockets too.

v2
---
 TODO                     |  2 --
 man/systemd.socket.xml   |  5 ++++-
 src/core/service.c       | 24 ++++++++++++++++++++++++
 src/shared/socket-util.c | 25 +++++++++++++++++++------
 4 files changed, 47 insertions(+), 9 deletions(-)

diff --git a/TODO b/TODO
index ae32388..780084a 100644
--- a/TODO
+++ b/TODO
@@ -164,8 +164,6 @@ Features:
 * as soon as we have kdbus, and sender timestamps, revisit coalescing multiple parallel daemon reloads:
   http://lists.freedesktop.org/archives/systemd-devel/2014-December/025862.html
 
-* set $REMOTE_IP (or $REMOTE_ADDR/$REMOTE_PORT) environment variable when doing per-connection socket activation. use format introduced by xinetd or CGI for this
-
 * the install state probably shouldn't get confused by generated units, think dbus1/kdbus compat!
 
 * in systemctl list-unit-files: show the install value the presets would suggest for a service in a third column
diff --git a/man/systemd.socket.xml b/man/systemd.socket.xml
index 3938345..8796d7b 100644
--- a/man/systemd.socket.xml
+++ b/man/systemd.socket.xml
@@ -357,7 +357,10 @@
         daemons designed for usage with
         <citerefentry><refentrytitle>inetd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
         to work unmodified with systemd socket
-        activation.</para></listitem>
+        activation.</para>
+        <para>For IPv4 and IPv6 connections the <varname>REMOTE_IP</varname>
+        environment variable will be set with remote IP and port seperated by a
+        colon (for SOCK_RAW the port is the IP protocol).</para></listitem>
       </varlistentry>
 
       <varlistentry>
diff --git a/src/core/service.c b/src/core/service.c
index a89ff3f..2ee4e11 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -1119,6 +1119,30 @@ static int service_spawn(
                         goto fail;
                 }
 
+        if (s->accept_socket.unit) {
+                union sockaddr_union pn;
+                socklen_t pnlen = sizeof(pn);
+                _cleanup_free_ char *remote_addr = NULL;
+
+                r = getpeername(s->socket_fd, &pn.sa, &pnlen);
+                if (r < 0) {
+                        r = -errno;
+                        goto fail;
+                }
+
+                if (pn.in.sin_family == AF_INET ||
+                    pn.in.sin_family == AF_INET6) {
+                        r = sockaddr_pretty(&pn.sa, pnlen, true, &remote_addr);
+                        if (r < 0)
+                                goto fail;
+
+                        if (asprintf(our_env + n_env++, "REMOTE_IP=%s", remote_addr) < 0) {
+                                r = -ENOMEM;
+                                goto fail;
+                        }
+                }
+        }
+
         final_env = strv_env_merge(2, UNIT(s)->manager->environment, our_env, NULL);
         if (!final_env) {
                 r = -ENOMEM;
diff --git a/src/shared/socket-util.c b/src/shared/socket-util.c
index 74d90fa..dbe2bf7 100644
--- a/src/shared/socket-util.c
+++ b/src/shared/socket-util.c
@@ -522,19 +522,32 @@ int sockaddr_pretty(const struct sockaddr *_sa, socklen_t salen, bool translate_
                                 return -ENOMEM;
 
                 } else if (sa->un.sun_path[0] == 0) {
+                        void *i;
                         /* abstract */
 
-                        /* FIXME: We assume we can print the
-                         * socket path here and that it hasn't
-                         * more than one NUL byte. That is
-                         * actually an invalid assumption */
-
+                        /* see unix(7), abstract is wierd */
+                        i = memchr(&sa->un.sun_path + 1, '\0', sizeof(sa->un.sun_path) - 1);
+                        if (i)
+                                for (i = (char *)i + 1;
+                                     (char *)i < &sa->un.sun_path[sizeof(sa->un.sun_path)];
+                                     i = (char *)i + 1)
+                                        if (*(char *)i != '\0') {
+                                                p = strdup("<abstract unprintable>");
+                                                if (!p)
+                                                        return -ENOMEM;
+
+                                                goto end;
+                                        }
+
+                        /* no non-NUL bytes after second NUL (if any) */
                         p = new(char, sizeof(sa->un.sun_path)+1);
                         if (!p)
                                 return -ENOMEM;
 
                         p[0] = '@';
                         memcpy(p+1, sa->un.sun_path+1, sizeof(sa->un.sun_path)-1);
+
+                        /* make printable if there was no second NUL (i == NULL) */
                         p[sizeof(sa->un.sun_path)] = 0;
 
                 } else {
@@ -549,7 +562,7 @@ int sockaddr_pretty(const struct sockaddr *_sa, socklen_t salen, bool translate_
                 return -ENOTSUP;
         }
 
-
+end:
         *ret = p;
         return 0;
 }
-- 
2.2.1.209.g41e5f3a