diff options
Diffstat (limited to 'src/udev/udev-builtin-hwdb.c')
| -rw-r--r-- | src/udev/udev-builtin-hwdb.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/src/udev/udev-builtin-hwdb.c b/src/udev/udev-builtin-hwdb.c new file mode 100644 index 0000000..19e07e7 --- /dev/null +++ b/src/udev/udev-builtin-hwdb.c @@ -0,0 +1,227 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <fnmatch.h> +#include <getopt.h> +#include <stdio.h> +#include <stdlib.h> + +#include "sd-hwdb.h" + +#include "alloc-util.h" +#include "device-util.h" +#include "hwdb-util.h" +#include "parse-util.h" +#include "string-util.h" +#include "udev-builtin.h" + +static sd_hwdb *hwdb; + +int udev_builtin_hwdb_lookup(sd_device *dev, + const char *prefix, const char *modalias, + const char *filter, bool test) { + _cleanup_free_ char *lookup = NULL; + const char *key, *value; + int n = 0, r; + + if (!hwdb) + return -ENOENT; + + if (prefix) { + lookup = strjoin(prefix, modalias); + if (!lookup) + return -ENOMEM; + modalias = lookup; + } + + SD_HWDB_FOREACH_PROPERTY(hwdb, modalias, key, value) { + if (filter && fnmatch(filter, key, FNM_NOESCAPE) != 0) + continue; + + r = udev_builtin_add_property(dev, test, key, value); + if (r < 0) + return r; + n++; + } + return n; +} + +static const char *modalias_usb(sd_device *dev, char *s, size_t size) { + const char *v, *p, *n = NULL; + uint16_t vn, pn; + + if (sd_device_get_sysattr_value(dev, "idVendor", &v) < 0) + return NULL; + if (sd_device_get_sysattr_value(dev, "idProduct", &p) < 0) + return NULL; + if (safe_atoux16(v, &vn) < 0) + return NULL; + if (safe_atoux16(p, &pn) < 0) + return NULL; + (void) sd_device_get_sysattr_value(dev, "product", &n); + + (void) snprintf(s, size, "usb:v%04Xp%04X:%s", vn, pn, strempty(n)); + return s; +} + +static int udev_builtin_hwdb_search(sd_device *dev, sd_device *srcdev, + const char *subsystem, const char *prefix, + const char *filter, bool test) { + char s[LINE_MAX]; + bool last = false; + int r = 0; + + assert(dev); + + if (!srcdev) + srcdev = dev; + + for (sd_device *d = srcdev; d; ) { + const char *dsubsys, *devtype, *modalias = NULL; + + if (sd_device_get_subsystem(d, &dsubsys) < 0) + goto next; + + /* look only at devices of a specific subsystem */ + if (subsystem && !streq(dsubsys, subsystem)) + goto next; + + (void) sd_device_get_property_value(d, "MODALIAS", &modalias); + + if (streq(dsubsys, "usb") && + sd_device_get_devtype(d, &devtype) >= 0 && + streq(devtype, "usb_device")) { + /* if the usb_device does not have a modalias, compose one */ + if (!modalias) + modalias = modalias_usb(d, s, sizeof(s)); + + /* avoid looking at any parent device, they are usually just a USB hub */ + last = true; + } + + if (!modalias) + goto next; + + log_device_debug(dev, "hwdb modalias key: \"%s\"", modalias); + + r = udev_builtin_hwdb_lookup(dev, prefix, modalias, filter, test); + if (r > 0) + break; + + if (last) + break; +next: + if (sd_device_get_parent(d, &d) < 0) + break; + } + + return r; +} + +static int builtin_hwdb(UdevEvent *event, int argc, char *argv[], bool test) { + static const struct option options[] = { + { "filter", required_argument, NULL, 'f' }, + { "device", required_argument, NULL, 'd' }, + { "subsystem", required_argument, NULL, 's' }, + { "lookup-prefix", required_argument, NULL, 'p' }, + {} + }; + const char *filter = NULL; + const char *device = NULL; + const char *subsystem = NULL; + const char *prefix = NULL; + _cleanup_(sd_device_unrefp) sd_device *srcdev = NULL; + sd_device *dev = ASSERT_PTR(ASSERT_PTR(event)->dev); + int r; + + if (!hwdb) + return -EINVAL; + + for (;;) { + int option; + + option = getopt_long(argc, argv, "f:d:s:p:", options, NULL); + if (option == -1) + break; + + switch (option) { + case 'f': + filter = optarg; + break; + + case 'd': + device = optarg; + break; + + case 's': + subsystem = optarg; + break; + + case 'p': + prefix = optarg; + break; + } + } + + /* query a specific key given as argument */ + if (argv[optind]) { + r = udev_builtin_hwdb_lookup(dev, prefix, argv[optind], filter, test); + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to look up hwdb: %m"); + if (r == 0) + return log_device_debug_errno(dev, SYNTHETIC_ERRNO(ENODATA), "No entry found from hwdb."); + return r; + } + + /* read data from another device than the device we will store the data */ + if (device) { + r = sd_device_new_from_device_id(&srcdev, device); + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to create sd_device object '%s': %m", device); + } + + r = udev_builtin_hwdb_search(dev, srcdev, subsystem, prefix, filter, test); + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to look up hwdb: %m"); + if (r == 0) + return log_device_debug_errno(dev, SYNTHETIC_ERRNO(ENODATA), "No entry found from hwdb."); + return r; +} + +/* called at udev startup and reload */ +static int builtin_hwdb_init(void) { + int r; + + if (hwdb) + return 0; + + r = sd_hwdb_new(&hwdb); + if (r < 0) + return r; + + return 0; +} + +/* called on udev shutdown and reload request */ +static void builtin_hwdb_exit(void) { + hwdb = sd_hwdb_unref(hwdb); +} + +/* called every couple of seconds during event activity; 'true' if config has changed */ +static bool builtin_hwdb_should_reload(void) { + if (hwdb_should_reload(hwdb)) { + log_debug("hwdb needs reloading."); + return true; + } + + return false; +} + +const UdevBuiltin udev_builtin_hwdb = { + .name = "hwdb", + .cmd = builtin_hwdb, + .init = builtin_hwdb_init, + .exit = builtin_hwdb_exit, + .should_reload = builtin_hwdb_should_reload, + .help = "Hardware database", +}; |