diff options
Diffstat (limited to 'src/core/kmod-setup.c')
| -rw-r--r-- | src/core/kmod-setup.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/src/core/kmod-setup.c b/src/core/kmod-setup.c new file mode 100644 index 0000000..15337d0 --- /dev/null +++ b/src/core/kmod-setup.c @@ -0,0 +1,158 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <unistd.h> + +#include "alloc-util.h" +#include "bus-util.h" +#include "capability-util.h" +#include "fileio.h" +#include "kmod-setup.h" +#include "macro.h" +#include "recurse-dir.h" +#include "string-util.h" +#include "strv.h" +#include "virt.h" + +#if HAVE_KMOD +#include "module-util.h" + +static void systemd_kmod_log( + void *data, + int priority, + const char *file, int line, + const char *fn, + const char *format, + va_list args) { + + /* library logging is enabled at debug only */ + DISABLE_WARNING_FORMAT_NONLITERAL; + log_internalv(LOG_DEBUG, 0, file, line, fn, format, args); + REENABLE_WARNING; +} + +static int has_virtio_rng_recurse_dir_cb( + RecurseDirEvent event, + const char *path, + int dir_fd, + int inode_fd, + const struct dirent *de, + const struct statx *sx, + void *userdata) { + + _cleanup_free_ char *alias = NULL; + int r; + + if (event != RECURSE_DIR_ENTRY) + return RECURSE_DIR_CONTINUE; + + if (de->d_type != DT_REG) + return RECURSE_DIR_CONTINUE; + + if (!streq(de->d_name, "modalias")) + return RECURSE_DIR_CONTINUE; + + r = read_one_line_file(path, &alias); + if (r < 0) { + log_debug_errno(r, "Failed to read %s, ignoring: %m", path); + return RECURSE_DIR_LEAVE_DIRECTORY; + } + + if (STARTSWITH_SET(alias, "pci:v00001AF4d00001005", "pci:v00001AF4d00001044")) + return 1; + + return RECURSE_DIR_LEAVE_DIRECTORY; +} + +static bool has_virtio_rng(void) { + int r; + + /* Directory traversal might be slow, hence let's do a cheap check first if it's even worth it */ + if (detect_vm() == VIRTUALIZATION_NONE) + return false; + + r = recurse_dir_at( + AT_FDCWD, + "/sys/devices/pci0000:00", + /* statx_mask= */ 0, + /* n_depth_max= */ 2, + RECURSE_DIR_ENSURE_TYPE, + has_virtio_rng_recurse_dir_cb, + NULL); + if (r < 0) + log_debug_errno(r, "Failed to determine whether host has virtio-rng device, ignoring: %m"); + + return r > 0; +} + +static bool in_qemu(void) { + return IN_SET(detect_vm(), VIRTUALIZATION_KVM, VIRTUALIZATION_QEMU); +} +#endif + +int kmod_setup(void) { +#if HAVE_KMOD + + static const struct { + const char *module; + const char *path; + bool warn_if_unavailable:1; + bool warn_if_module:1; + bool (*condition_fn)(void); + } kmod_table[] = { + /* This one we need to load explicitly, since auto-loading on use doesn't work + * before udev created the ghost device nodes, and we need it earlier than that. */ + { "autofs4", "/sys/class/misc/autofs", true, false, NULL }, + + /* This one we need to load explicitly, since auto-loading of IPv6 is not done when + * we try to configure ::1 on the loopback device. */ + { "ipv6", "/sys/module/ipv6", false, true, NULL }, + + /* This should never be a module */ + { "unix", "/proc/net/unix", true, true, NULL }, + +#if HAVE_LIBIPTC + /* netfilter is needed by networkd, nspawn among others, and cannot be autoloaded */ + { "ip_tables", "/proc/net/ip_tables_names", false, false, NULL }, +#endif + /* virtio_rng would be loaded by udev later, but real entropy might be needed very early */ + { "virtio_rng", NULL, false, false, has_virtio_rng }, + + /* qemu_fw_cfg would be loaded by udev later, but we want to import credentials from it super early */ + { "qemu_fw_cfg", "/sys/firmware/qemu_fw_cfg", false, false, in_qemu }, + + /* dmi-sysfs is needed to import credentials from it super early */ + { "dmi-sysfs", "/sys/firmware/dmi/entries", false, false, NULL }, + }; + _cleanup_(kmod_unrefp) struct kmod_ctx *ctx = NULL; + unsigned i; + + if (have_effective_cap(CAP_SYS_MODULE) == 0) + return 0; + + for (i = 0; i < ELEMENTSOF(kmod_table); i++) { + if (kmod_table[i].path && access(kmod_table[i].path, F_OK) >= 0) + continue; + + if (kmod_table[i].condition_fn && !kmod_table[i].condition_fn()) + continue; + + if (kmod_table[i].warn_if_module) + log_debug("Your kernel apparently lacks built-in %s support. Might be " + "a good idea to compile it in. We'll now try to work around " + "this by loading the module...", kmod_table[i].module); + + if (!ctx) { + ctx = kmod_new(NULL, NULL); + if (!ctx) + return log_oom(); + + kmod_set_log_fn(ctx, systemd_kmod_log, NULL); + kmod_load_resources(ctx); + } + + (void) module_load_and_warn(ctx, kmod_table[i].module, kmod_table[i].warn_if_unavailable); + } + +#endif + return 0; +} |