kmod: automatically load a few kernel modules we need for normal operation before udev is active

1 files changed, 107 insertions, 0 deletions

diff --git a/src/kmod-setup.c b/src/kmod-setup.c
new file mode 100644
index 0000000000..fa856c9a6c
--- /dev/null
+++ b/src/kmod-setup.c
@@ -0,0 +1,107 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/wait.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#include "macro.h"
+#include "execute.h"
+
+#include "kmod-setup.h"
+
+static const char * const kmod_table[] = {
+        "autofs4", "/sys/class/misc/autofs",
+        "ipv6",    "/sys/module/ipv6"
+};
+
+int kmod_setup(void) {
+        unsigned i, n = 0;
+        const char * cmdline[3 + ELEMENTSOF(kmod_table) + 1];
+        ExecCommand command;
+        ExecContext context;
+        pid_t pid;
+        int status, r;
+
+        for (i = 0; i < ELEMENTSOF(kmod_table); i += 2) {
+
+                if (access(kmod_table[i+1], F_OK) >= 0)
+                        continue;
+
+                log_info("Your kernel apparently lacks built-in %s support. Please fix that. "
+                         "We'll now try to work around this by calling '/sbin/modprobe %s'...",
+                         kmod_table[i], kmod_table[i]);
+
+                cmdline[3 + n++] = kmod_table[i];
+        }
+
+        if (n <= 0)
+                return 0;
+
+        cmdline[0] = "/sbin/modprobe";
+        cmdline[1] = "-qab";
+        cmdline[2] = "--";
+        cmdline[3 + n] = NULL;
+
+        zero(command);
+        zero(context);
+
+        command.path = (char*) cmdline[0];
+        command.argv = (char**) cmdline;
+
+        exec_context_init(&context);
+        r = exec_spawn(&command, NULL, &context, NULL, 0, NULL, false, false, false, NULL, &pid);
+        exec_context_done(&context);
+
+        if (r < 0)
+                return r;
+
+        for (;;) {
+                if (waitpid(pid, &status, 0) < 0) {
+
+                        if (errno == EINTR)
+                                continue;
+
+                        return -errno;
+                }
+
+                break;
+        }
+
+        if (WIFEXITED(status)) {
+                if (WEXITSTATUS(status) != 0) {
+                        log_warning("/sbin/modprobe failed with error code %i.", WEXITSTATUS(status));
+                        return -EPROTO;
+                }
+
+                log_debug("/sbin/modprobe succeeded.");
+                return 0;
+        }
+
+        if (WIFSIGNALED(status)) {
+                log_warning("/sbin/modprobe terminated by signal %s.", strsignal(WTERMSIG(status)));
+                return -EPROTO;
+        }
+
+        log_warning("/sbin/modprobe failed due to unknown reason.");
+        return -EPROTO;
+}