core: pass the socket cookie to invoked per-connection service instances as $SO_COOKIE env var

The socket cookie is just too useful for identifying connections, let's
emphasize this a bit and pass it as environment variable.
This commit is contained in:
Lennart Poettering
2025-05-15 09:15:46 +02:00
parent 272017d32a
commit bfb1f9e2c9
3 changed files with 29 additions and 4 deletions

View File

@@ -4412,6 +4412,17 @@ StandardInputData=V2XigLJyZSBubyBzdHJhbmdlcnMgdG8gbG92ZQpZb3Uga25vdyB0aGUgcnVsZX
<xi:include href="version-info.xml" xpointer="v220"/></listitem>
</varlistentry>
<varlistentry>
<term><varname>$SO_COOKIE</varname></term>
<listitem><para>If this is a unit started via per-connection socket activation (i.e. via a socket
unit with <varname>Accept=yes</varname>), this environment variable contains the Linux socket
cookie, formatted as decimal integer. The socket cookie can otherwise be acquired via <citerefentry
project='man-pages'><refentrytitle>getsockopt</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
<xi:include href="version-info.xml" xpointer="v258"/></listitem>
</varlistentry>
<varlistentry>
<term><varname>$TRIGGER_UNIT</varname></term>
<term><varname>$TRIGGER_PATH</varname></term>

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@@ -425,13 +425,19 @@
above for a more detailed discussion of the naming rules of triggered services.</para>
<para>For IPv4 and IPv6 connections, the <varname>$REMOTE_ADDR</varname> environment variable will
contain the remote IP address, and <varname>$REMOTE_PORT</varname> will contain the remote port. This
is the same as the format used by CGI.</para>
contain the remote IP address, and <varname>$REMOTE_PORT</varname> will contain the remote port
number. These two variables correspond to those defined by the CGI interface for web services (see
<ulink url="https://datatracker.ietf.org/doc/html/rfc3875">RFC 3875</ulink>).</para>
<para>For <constant>AF_UNIX</constant> socket connections, the <varname>$REMOTE_ADDR</varname>
environment variable will contain either the remote socket's file system path starting with a slash
(<literal>/</literal>) or its address in the abstract namespace starting with an at symbol
(<literal>@</literal>). If the socket is unnamed, <varname>$REMOTE_ADDR</varname> will not be set.</para>
(<literal>@</literal>). If the socket is unnamed, <varname>$REMOTE_ADDR</varname> will not be
set.</para>
<para>The <varname>$SO_COOKIE</varname> environment variable is set to the Linux socket cookie,
formatted as decimal integer. The socket cookie can otherwise be acquired via <citerefentry
project='man-pages'><refentrytitle>getsockopt</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
<para>It is recommended to set <varname>CollectMode=inactive-or-failed</varname> for service
instances activated via <varname>Accept=yes</varname>, to ensure that failed connection services are

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@@ -1749,7 +1749,7 @@ static int service_spawn_internal(
if (r < 0)
return r;
our_env = new0(char*, 15);
our_env = new0(char*, 16);
if (!our_env)
return -ENOMEM;
@@ -1821,6 +1821,14 @@ static int service_spawn_internal(
our_env[n_env++] = t;
}
}
uint64_t cookie;
if (socket_get_cookie(s->socket_fd, &cookie) >= 0) {
char *t;
if (asprintf(&t, "SO_COOKIE=%" PRIu64, cookie) < 0)
return -ENOMEM;
our_env[n_env++] = t;
}
}
Service *env_source = NULL;