From b2a21a35476b4780ef1fc68c60216117ab66fa2b Mon Sep 17 00:00:00 2001 From: "kay.sievers@vrfy.org" Date: Mon, 19 Jan 2004 19:40:32 -0800 Subject: [PATCH] [PATCH] udev - reverse user query options Here we get the ability to query with the name of the node instead of the device path. It uses a linear search over the whole database. kay@pim:~/src/udev.kay$ ./udev -q path -n video/webcam0 /class/video4linux/video0 New version, with better function return codes for error handling. --- udev.8 | 7 ++-- udev.c | 104 +++++++++++++++++++++++++++++++++++++------------------ udevdb.c | 49 ++++++++++++++++++++++---- udevdb.h | 3 +- 4 files changed, 120 insertions(+), 43 deletions(-) diff --git a/udev.8 b/udev.8 index 0421fee4e6..ff89e435ff 100644 --- a/udev.8 +++ b/udev.8 @@ -50,10 +50,13 @@ will be prepended. .BI -q " query_type" Query the database for specified value of a created device node. Valid types are: -.BR name ", " symlink ", " owner " or " group . +.BR name ", " symlink ", " owner " , " group " or " path. .TP .BI -p " sysfs_path" -Specify the sysfs path needed for the query. +Specify the sysfs path of the device to query. +.TP +.BI -n " name" +Specify the name of the node for the device to query. .TP .B -d Dump the whole database. diff --git a/udev.c b/udev.c index b872f42494..3b701ac26f 100644 --- a/udev.c +++ b/udev.c @@ -83,7 +83,8 @@ static inline char *get_seqnum(void) return seqnum; } -static void print_record(char *path, struct udevice *dev) +/* callback for database dump */ +static int print_record(char *path, struct udevice *dev) { printf("P: %s\n", path); printf("N: %s\n", dev->name); @@ -91,11 +92,13 @@ static void print_record(char *path, struct udevice *dev) printf("O: %s\n", dev->owner); printf("G: %s\n", dev->group); printf("\n"); + return 0; } enum query_type { NONE, NAME, + PATH, SYMLINK, OWNER, GROUP @@ -103,7 +106,7 @@ enum query_type { static inline int udev_user(int argc, char **argv) { - static const char short_options[] = "dp:q:rVh"; + static const char short_options[] = "dn:p:q:rVh"; int option; int retval = -EINVAL; struct udevice dev; @@ -111,6 +114,7 @@ static inline int udev_user(int argc, char **argv) enum query_type query = NONE; char result[NAME_SIZE] = ""; char path[NAME_SIZE] = ""; + char name[NAME_SIZE] = ""; /* get command line options */ while (1) { @@ -120,6 +124,11 @@ static inline int udev_user(int argc, char **argv) dbg("option '%c'", option); switch (option) { + case 'n': + dbg("udev name: %s\n", optarg); + strfieldcpy(name, optarg); + break; + case 'p': dbg("udev path: %s\n", optarg); strfieldcpy(path, optarg); @@ -148,6 +157,11 @@ static inline int udev_user(int argc, char **argv) break; } + if (strcmp(optarg, "path") == 0) { + query = PATH; + break; + } + printf("unknown query type\n"); return -EINVAL; @@ -161,7 +175,7 @@ static inline int udev_user(int argc, char **argv) printf("unable to open udev database\n"); return -EACCES; } - retval = udevdb_dump(print_record); + retval = udevdb_call_foreach(print_record); udevdb_exit(); return retval; @@ -179,44 +193,63 @@ static inline int udev_user(int argc, char **argv) /* process options */ if (query != NONE) { - if (path[0] == '\0') { - printf("query needs device path specified\n"); - return -EINVAL; - } - retval = udevdb_open_ro(); if (retval != 0) { printf("unable to open udev database\n"); return -EACCES; } - retval = udevdb_get_dev(path, &dev); - if (retval == 0) { - switch(query) { - case NAME: - if (root) - strfieldcpy(result, udev_root); - strncat(result, dev.name, sizeof(result)); - break; - case SYMLINK: - strfieldcpy(result, dev.symlink); - break; - - case GROUP: - strfieldcpy(result, dev.group); - break; - - case OWNER: - strfieldcpy(result, dev.owner); - break; - - default: - break; + if (path[0] != '\0') { + retval = udevdb_get_dev(path, &dev); + if (retval != 0) { + printf("device not found in database\n"); + goto exit; } - printf("%s\n", result); - } else { - printf("device not found in udev database\n"); + goto print; } + + if (name[0] != '\0') { + retval = udevdb_get_dev_byname(name, path, &dev); + if (retval != 0) { + printf("device not found in database\n"); + goto exit; + } + goto print; + } + + printf("query needs device path(-p) or node name(-n) specified\n"); + goto exit; + +print: + switch(query) { + case NAME: + if (root) + strfieldcpy(result, udev_root); + strncat(result, dev.name, sizeof(result)); + break; + + case SYMLINK: + strfieldcpy(result, dev.symlink); + break; + + case GROUP: + strfieldcpy(result, dev.group); + break; + + case OWNER: + strfieldcpy(result, dev.owner); + break; + + case PATH: + strfieldcpy(result, path); + break; + + default: + goto exit; + } + printf("%s\n", result); + +exit: udevdb_exit(); return retval; } @@ -227,13 +260,16 @@ static inline int udev_user(int argc, char **argv) } help: - printf("Usage: [-pqrdVh]\n" + printf("Usage: [-npqrdVh]\n" " -q TYPE query database for the specified value:\n" " 'name' name of device node\n" " 'symlink' pointing to node\n" " 'owner' of node\n" " 'group' of node\n" + " 'path' sysfs device path\n" " -p PATH sysfs device path used for query\n" + " -n NAME node name used for query\n" + "\n" " -r print udev root\n" " -d dump whole database\n" " -V print udev version\n" diff --git a/udevdb.c b/udevdb.c index 2d99f51d0e..c4e064fc11 100644 --- a/udevdb.c +++ b/udevdb.c @@ -143,25 +143,62 @@ int udevdb_open_ro(void) return 0; } -void (*user_record_callback) (char *path, struct udevice *dev); +static int (*user_record_callback) (char *path, struct udevice *dev); static int traverse_callback(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state) { - user_record_callback((char*) key.dptr, (struct udevice*) dbuf.dptr); - return 0; + return user_record_callback((char*) key.dptr, (struct udevice*) dbuf.dptr); } /** - * udevdb_dump: dumps whole database by passing record data to user function + * udevdb_call_foreach: dumps whole database by passing record data to user function * @user_record_handler: user function called for every record in the database */ -int udevdb_dump(void (*user_record_handler) (char *path, struct udevice *dev)) +int udevdb_call_foreach(int (*user_record_handler) (char *path, struct udevice *dev)) { + int retval = 0; + if (user_record_handler == NULL) { dbg("invalid user record handling function"); return -EINVAL; } user_record_callback = user_record_handler; - tdb_traverse(udevdb, traverse_callback, NULL); + retval = tdb_traverse(udevdb, traverse_callback, NULL); + if (retval < 0) + return -ENODEV; + else + return 0; +} + +static struct udevice *find_dev; +static char *find_path; +static const char *find_name; +static int find_found; + +static int find_device_by_name(char *path, struct udevice *dev) +{ + if (strncmp(dev->name, find_name, sizeof(dev->name)) == 0) { + memcpy(find_dev, dev, sizeof(*find_dev)); + strncpy(find_path, path, NAME_SIZE); + find_found = 1; + /* stop search */ + return 1; + } return 0; } + +/** + * udevdb_get_dev_byname: search device with given name by traversing the whole database + */ +int udevdb_get_dev_byname(const char *name, char *path, struct udevice *dev) +{ + find_found = 0; + find_path = path; + find_dev = dev; + find_name = name; + udevdb_call_foreach(find_device_by_name); + if (find_found == 1) + return 0; + else + return -1; +} diff --git a/udevdb.h b/udevdb.h index a0e5338265..6eaeb25668 100644 --- a/udevdb.h +++ b/udevdb.h @@ -12,10 +12,11 @@ extern void udevdb_exit(void); extern int udevdb_init(int init_flag); extern int udevdb_open_ro(void); -extern int udevdb_dump(void (*user_record_handler) (char *path, struct udevice *dev)); +extern int udevdb_call_foreach(int (*user_record_handler) (char *path, struct udevice *dev)); extern int udevdb_add_dev(const char *path, const struct udevice *dev); extern int udevdb_get_dev(const char *path, struct udevice *dev); extern int udevdb_delete_dev(const char *path); +extern int udevdb_get_dev_byname(const char *name, char *path, struct udevice *dev); #endif /* _UDEVDB_H_ */