From 33488f19793dc0a86fdee27266c5319b5b78d695 Mon Sep 17 00:00:00 2001 From: Martin Pitt Date: Fri, 17 Oct 2014 15:01:01 +0200 Subject: [PATCH] udev hwdb: Support shipping pre-compiled database in system images In some cases it is preferable to ship system images with a pre-generated binary hwdb database, to avoid having to build it at runtime, avoid shipping the source hwdb files, or avoid storing large binary files in /etc. So if hwdb.bin does not exist in /etc/udev/, fall back to looking for it in UDEVLIBEXECDIR. This keeps the possibility to add files to /etc/udev/hwdb.d/ and re-generating the database which trumps the one in /usr/lib. Add a new --usr flag to "udevadm hwdb --update" which puts the database into UDEVLIBEXECDIR. Adjust systemd-udev-hwdb-update.service to not generate the file in /etc if we already have it in /usr. --- man/udev.xml | 4 ++- man/udevadm.xml | 9 +++++ src/libudev/libudev-hwdb.c | 42 +++++++++++++++++++---- src/udev/udevadm-hwdb.c | 13 ++++++- units/systemd-udev-hwdb-update.service.in | 3 ++ 5 files changed, 63 insertions(+), 8 deletions(-) diff --git a/man/udev.xml b/man/udev.xml index d77cbb0e6..87c16c78e 100644 --- a/man/udev.xml +++ b/man/udev.xml @@ -766,7 +766,9 @@ The content of all hwdb files is read by udevadm8 - and compiled to a binary database located at /etc/udev/hwdb.bin. + and compiled to a binary database located at /etc/udev/hwdb.bin, + or alternatively /usr/lib/udev/hwdb.bin if you want ship the compiled + database in an immutable image. During runtime only the binary database is used. diff --git a/man/udevadm.xml b/man/udevadm.xml index 749144dbd..b85d9a924 100644 --- a/man/udevadm.xml +++ b/man/udevadm.xml @@ -493,6 +493,15 @@ notified about it. + + + + Put the compiled database into /usr/lib/udev/hwdb.bin instead. + Use this if you want to ship a pre-compiled database in immutable system images, or + don't use /etc/udev/hwdb.d and want to avoid large binary files in + /etc. + + diff --git a/src/libudev/libudev-hwdb.c b/src/libudev/libudev-hwdb.c index 8fb724040..a1cfc0bd5 100644 --- a/src/libudev/libudev-hwdb.c +++ b/src/libudev/libudev-hwdb.c @@ -256,6 +256,11 @@ static int trie_search_f(struct udev_hwdb *hwdb, const char *search) { return 0; } +static const char hwdb_bin_paths[] = + "/etc/udev/hwdb.bin\0" + UDEVLIBEXECDIR "/hwdb.bin\0"; + + /** * udev_hwdb_new: * @udev: udev library context @@ -266,6 +271,7 @@ static int trie_search_f(struct udev_hwdb *hwdb, const char *search) { **/ _public_ struct udev_hwdb *udev_hwdb_new(struct udev *udev) { struct udev_hwdb *hwdb; + const char *hwdb_bin_path; const char sig[] = HWDB_SIG; hwdb = new0(struct udev_hwdb, 1); @@ -275,30 +281,43 @@ _public_ struct udev_hwdb *udev_hwdb_new(struct udev *udev) { hwdb->refcount = 1; udev_list_init(udev, &hwdb->properties_list, true); - hwdb->f = fopen("/etc/udev/hwdb.bin", "re"); + /* find hwdb.bin in hwdb_bin_paths */ + NULSTR_FOREACH(hwdb_bin_path, hwdb_bin_paths) { + hwdb->f = fopen(hwdb_bin_path, "re"); + if (hwdb->f) + break; + else if (errno == ENOENT) + continue; + else { + udev_dbg(udev, "error reading %s: %m", hwdb_bin_path); + udev_hwdb_unref(hwdb); + return NULL; + } + } + if (!hwdb->f) { - udev_dbg(udev, "error reading /etc/udev/hwdb.bin: %m"); + udev_err(udev, "hwdb.bin does not exist, please run udevadm hwdb --update"); udev_hwdb_unref(hwdb); return NULL; } if (fstat(fileno(hwdb->f), &hwdb->st) < 0 || (size_t)hwdb->st.st_size < offsetof(struct trie_header_f, strings_len) + 8) { - udev_dbg(udev, "error reading /etc/udev/hwdb.bin: %m"); + udev_dbg(udev, "error reading %s: %m", hwdb_bin_path); udev_hwdb_unref(hwdb); return NULL; } hwdb->map = mmap(0, hwdb->st.st_size, PROT_READ, MAP_SHARED, fileno(hwdb->f), 0); if (hwdb->map == MAP_FAILED) { - udev_dbg(udev, "error mapping /etc/udev/hwdb.bin: %m"); + udev_dbg(udev, "error mapping %s: %m", hwdb_bin_path); udev_hwdb_unref(hwdb); return NULL; } if (memcmp(hwdb->map, sig, sizeof(hwdb->head->signature)) != 0 || (size_t)hwdb->st.st_size != le64toh(hwdb->head->file_size)) { - udev_dbg(udev, "error recognizing the format of /etc/udev/hwdb.bin"); + udev_dbg(udev, "error recognizing the format of %s", hwdb_bin_path); udev_hwdb_unref(hwdb); return NULL; } @@ -352,14 +371,25 @@ _public_ struct udev_hwdb *udev_hwdb_unref(struct udev_hwdb *hwdb) { } bool udev_hwdb_validate(struct udev_hwdb *hwdb) { + bool found = false; + const char* p; struct stat st; if (!hwdb) return false; if (!hwdb->f) return false; - if (stat("/etc/udev/hwdb.bin", &st) < 0) + + /* if hwdb.bin doesn't exist anywhere, we need to update */ + NULSTR_FOREACH(p, hwdb_bin_paths) { + if (stat(p, &st) >= 0) { + found = true; + break; + } + } + if (!found) return true; + if (timespec_load(&hwdb->st.st_mtim) != timespec_load(&st.st_mtim)) return true; return false; diff --git a/src/udev/udevadm-hwdb.c b/src/udev/udevadm-hwdb.c index 64273fbe8..3ca755e2e 100644 --- a/src/udev/udevadm-hwdb.c +++ b/src/udev/udevadm-hwdb.c @@ -536,14 +536,20 @@ static int import_file(struct udev *udev, struct trie *trie, const char *filenam static void help(void) { printf("Usage: udevadm hwdb OPTIONS\n" " -u,--update update the hardware database\n" + " --usr generate in " UDEVLIBEXECDIR " instead of /etc/udev\n" " -t,--test=MODALIAS query database and print result\n" " -r,--root=PATH alternative root path in the filesystem\n" " -h,--help\n\n"); } static int adm_hwdb(struct udev *udev, int argc, char *argv[]) { + enum { + ARG_USR = 0x100, + }; + static const struct option options[] = { { "update", no_argument, NULL, 'u' }, + { "usr", no_argument, NULL, ARG_USR }, { "test", required_argument, NULL, 't' }, { "root", required_argument, NULL, 'r' }, { "help", no_argument, NULL, 'h' }, @@ -551,6 +557,7 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) { }; const char *test = NULL; const char *root = ""; + const char *hwdb_bin_dir = "/etc/udev"; bool update = false; struct trie *trie = NULL; int err, c; @@ -561,6 +568,9 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) { case 'u': update = true; break; + case ARG_USR: + hwdb_bin_dir = UDEVLIBEXECDIR; + break; case 't': test = optarg; break; @@ -634,7 +644,8 @@ static int adm_hwdb(struct udev *udev, int argc, char *argv[]) { log_debug("strings dedup'ed: %8zu bytes (%8zu)", trie->strings->dedup_len, trie->strings->dedup_count); - if (asprintf(&hwdb_bin, "%s/etc/udev/hwdb.bin", root) < 0) { + hwdb_bin = strjoin(root, "/", hwdb_bin_dir, "/hwdb.bin", NULL); + if (!hwdb_bin) { rc = EXIT_FAILURE; goto out; } diff --git a/units/systemd-udev-hwdb-update.service.in b/units/systemd-udev-hwdb-update.service.in index cdbcd837c..5b1f75d25 100644 --- a/units/systemd-udev-hwdb-update.service.in +++ b/units/systemd-udev-hwdb-update.service.in @@ -13,6 +13,9 @@ Conflicts=shutdown.target After=systemd-remount-fs.service Before=sysinit.target shutdown.target systemd-update-done.service ConditionNeedsUpdate=/etc +ConditionPathExists=|!@udevlibexecdir@/hwdb.bin +ConditionPathExists=|/etc/udev/hwdb.bin +ConditionDirectoryNotEmpty=|/etc/udev/hwdb.d/ [Service] Type=oneshot -- 2.30.2