commit c17b7a2201250eaa9aac012b0f5de6e70365e60e
Author: Jeltz <tom.barthe+aurore@ens-paris-saclay.fr>
Date:   Sat Jun 12 00:43:17 2021 +0200

    Initial commit

diff --git a/mod_unix_socket.c b/mod_unix_socket.c
new file mode 100644
index 0000000..7f2a2f5
--- /dev/null
+++ b/mod_unix_socket.c
@@ -0,0 +1,170 @@
+#include <unistd.h>
+#include "httpd.h"
+#include "http_config.h"
+#include "http_protocol.h"
+#include "ap_config.h"
+#include "ap_listen.h"
+#include "apr_strings.h"
+#include "http_log.h"
+
+static ap_listen_rec *
+alloc_unix_listener (process_rec * process, const char *path,
+		     const char *proto)
+{
+  struct sockaddr_un sun = {
+    .sun_family = AF_UNIX,
+  };
+  apr_os_sock_info_t si;
+  ap_listen_rec *rec;
+  apr_status_t rv;
+  int one = 1;
+  int fd;
+
+  apr_cpystrn (sun.sun_path, path, sizeof (sun.sun_path));
+
+  rec = apr_palloc (process->pool, sizeof (*rec));
+  rec->protocol = apr_pstrdup (process->pool, proto);
+  rec->accept_func = NULL;
+  rec->next = NULL;
+  rec->active = 1;
+
+  if (unlink (sun.sun_path))
+    {
+      ap_log_perror (APLOG_MARK, APLOG_CRIT, APR_EGENERAL, process->pool,
+		     APLOGNO (10100) "unlink failed: %s", strerror (errno));
+      return NULL;
+    }
+
+  fd = socket (AF_UNIX, SOCK_STREAM, 0);
+  if (fd == -1)
+    {
+      ap_log_perror (APLOG_MARK, APLOG_CRIT, APR_EGENERAL, process->pool,
+		     APLOGNO (10101) "socket failed: %s", strerror (errno));
+      return NULL;
+    }
+
+  if (setsockopt (fd, SOL_SOCKET, SO_REUSEPORT,
+		  (void *) &one, sizeof (one)) < 0)
+    {
+      ap_log_perror (APLOG_MARK, APLOG_CRIT, APR_EGENERAL, process->pool,
+		     APLOGNO (10102) "setsockopt failed: %s",
+		     strerror (errno));
+      close (fd);
+      return NULL;
+    }
+
+  /* apr_socket_bind() is not used because apr_sockaddr_t is not compatible
+   * with sockaddr_un
+   */
+  if (bind (fd, (struct sockaddr *) &sun, sizeof (sun)))
+    {
+      ap_log_perror (APLOG_MARK, APLOG_CRIT, APR_EGENERAL, process->pool,
+		     APLOGNO (10103) "bind failed: %s", strerror (errno));
+      close (fd);
+      return NULL;
+    }
+
+  /* FIXME (ugly hack): configure fake socket information to allow
+   * ap_setup_listeners() to set the protocol of servers.
+   * I don't know if it interacts well with other parts of the codebase
+   * (I haven't even checked properly the whole server/listen.c file!)
+   */
+  si.os_sock = &fd;
+  si.remote = NULL;
+  si.local = NULL;
+  si.family = APR_INET;
+  si.type = SOCK_STREAM;
+  si.protocol = APR_PROTO_TCP;
+
+  rv = apr_os_sock_make (&rec->sd, &si, process->pool);
+  if (rv != APR_SUCCESS)
+    {
+      ap_log_perror (APLOG_MARK, APLOG_CRIT, APR_EGENERAL, process->pool,
+		     APLOGNO (10104) "apr_os_sock_make failed (%d)", fd);
+      close (fd);
+      return NULL;
+    }
+
+  rv = apr_socket_listen (rec->sd, 10);
+  if (rv != APR_SUCCESS)
+    {
+      ap_log_perror (APLOG_MARK, APLOG_CRIT, rv, process->pool,
+		     APLOGNO (10105) "apr_socket_listen failed (%d)", fd);
+      return NULL;
+    }
+
+  rv = apr_socket_addr_get (&rec->bind_addr, APR_LOCAL, rec->sd);
+  if (rv != APR_SUCCESS)
+    {
+      ap_log_perror (APLOG_MARK, APLOG_CRIT, rv, process->pool,
+		     APLOGNO (10106) "apr_socket_addr_get failed (%d)", fd);
+      return NULL;
+    }
+
+  /* TODO: implement useful parts of make_sock (server/listen.c) */
+
+  return rec;
+}
+
+
+static const char *
+set_listen_path (cmd_parms * cmd, void *cfg, const char *path,
+		 const char *proto)
+{
+  ap_listen_rec *last;
+  ap_listen_rec *new;
+  apr_status_t rv;
+  const char *err;
+
+  err = ap_check_cmd_context (cmd, GLOBAL_ONLY);
+  if (err)
+    {
+      return err;
+    }
+
+  if (strcmp (proto, "http") && strcmp (proto, "https"))
+    {
+      return "Proto must be either 'http' or 'https'";
+    }
+
+  new = alloc_unix_listener (cmd->server->process, path, proto);
+  if (!new)
+    {
+      return "Failed to listen on Unix socket";
+    }
+
+  last = ap_listeners;
+
+  while (last && last->next)
+    {
+      last = last->next;
+    }
+
+  if (!last)
+    {
+      ap_listeners = new;
+    }
+  else
+    {
+      last->next = new;
+    }
+
+  return NULL;
+}
+
+static const command_rec directives[] = {
+  AP_INIT_TAKE2 ("ListenUnixPath", set_listen_path, NULL, RSRC_CONF,
+		 "Listen to Unix socket"),
+  {NULL},
+};
+
+
+module AP_MODULE_DECLARE_DATA unix_socket_module = {
+  STANDARD20_MODULE_STUFF,
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  directives,
+  NULL,
+};