-/* vi:set ts=4:
- *
+/* vi: set sw=4 ts=4: */
+/*
+ *
* mdev - Mini udev for busybox
- *
+ *
* Copyright 2005 Rob Landley <rob@landley.net>
* Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPL version 2, see file LICENSE in this tarball for details.
*/
-#include <ctype.h>
-#include <dirent.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <string.h>
-#include <sys/mman.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include "busybox.h"
+#include "libbb.h"
#include "xregex.h"
-#define DEV_PATH "/dev"
+struct globals {
+ int root_major, root_minor;
+};
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define root_major (G.root_major)
+#define root_minor (G.root_minor)
+
+/* Prevent infinite loops in /sys symlinks */
+#define MAX_SYSFS_DEPTH 3
-#include <busybox.h>
+/* We use additional 64+ bytes in make_device() */
+#define SCRATCH_SIZE 80
+
+#if ENABLE_FEATURE_MDEV_RENAME
+/* Builds an alias path.
+ * This function potentionally reallocates the alias parameter.
+ */
+static char *build_alias(char *alias, const char *device_name)
+{
+ char *dest;
+
+ /* ">bar/": rename to bar/device_name */
+ /* ">bar[/]baz": rename to bar[/]baz */
+ dest = strrchr(alias, '/');
+ if (dest) { /* ">bar/[baz]" ? */
+ *dest = '\0'; /* mkdir bar */
+ bb_make_directory(alias, 0755, FILEUTILS_RECUR);
+ *dest = '/';
+ if (dest[1] == '\0') { /* ">bar/" => ">bar/device_name" */
+ dest = alias;
+ alias = concat_path_file(alias, device_name);
+ free(dest);
+ }
+ }
+
+ return alias;
+}
+#endif
/* mknod in /dev based on a path like "/sys/block/hda/hda1" */
-static void make_device(char *path)
+/* NB: "mdev -s" may call us many times, do not leak memory/fds! */
+static void make_device(char *path, int delete)
{
- char *device_name,*s;
- int major,minor,type,len,fd;
- int mode=0660;
- uid_t uid=0;
- gid_t gid=0;
-
- RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
-
- /* Try to read major/minor string */
-
- snprintf(temp, PATH_MAX, "%s/dev", path);
- fd = open(temp, O_RDONLY);
- len = read(fd, temp, PATH_MAX-1);
- if (len<1) goto end;
- temp[--len] = 0; // remove trailing \n
- close(fd);
-
- /* Determine device name, type, major and minor */
-
- device_name = strrchr(path, '/') + 1;
- type = strncmp(path+5, "block/" ,6) ? S_IFCHR : S_IFBLK;
- major = minor = 0;
- for (s = temp; *s; s++) {
- if (*s == ':') {
- major = minor;
- minor = 0;
- } else {
- minor *= 10;
- minor += (*s) - '0';
+ const char *device_name;
+ int major, minor, type, len;
+ int mode = 0660;
+#if ENABLE_FEATURE_MDEV_CONF
+ struct bb_uidgid_t ugid = { 0, 0 };
+ parser_t *parser;
+ char *tokens[5];
+#endif
+#if ENABLE_FEATURE_MDEV_EXEC
+ char *command = NULL;
+#endif
+#if ENABLE_FEATURE_MDEV_RENAME
+ char *alias = NULL;
+ char aliaslink = aliaslink; /* for compiler */
+#endif
+ char *dev_maj_min = path + strlen(path);
+
+ /* Force the configuration file settings exactly. */
+ umask(0);
+
+ /* Try to read major/minor string. Note that the kernel puts \n after
+ * the data, so we don't need to worry about null terminating the string
+ * because sscanf() will stop at the first nondigit, which \n is.
+ * We also depend on path having writeable space after it.
+ */
+ major = -1;
+ if (!delete) {
+ strcpy(dev_maj_min, "/dev");
+ len = open_read_close(path, dev_maj_min + 1, 64);
+ *dev_maj_min++ = '\0';
+ if (len < 1) {
+ if (!ENABLE_FEATURE_MDEV_EXEC)
+ return;
+ /* no "dev" file, so just try to run script */
+ *dev_maj_min = '\0';
+ } else if (sscanf(dev_maj_min, "%u:%u", &major, &minor) != 2) {
+ major = -1;
}
}
- /* If we have a config file, look up permissions for this device */
-
- if (ENABLE_FEATURE_MDEV_CONF) {
- char *conf,*pos,*end;
-
- /* mmap the config file */
- if (-1!=(fd=open("/etc/mdev.conf",O_RDONLY))) {
- len=lseek(fd,0,SEEK_END);
- conf=mmap(NULL,len,PROT_READ,MAP_PRIVATE,fd,0);
- if (conf) {
- int line=0;
-
- /* Loop through lines in mmaped file*/
- for (pos=conf;pos-conf<len;) {
- int field;
- char *end2;
-
- line++;
- /* find end of this line */
- for(end=pos;end-conf<len && *end!='\n';end++);
-
- /* Three fields: regex, uid:gid, mode */
- for (field=3;field;field--) {
- /* Skip whitespace */
- while (pos<end && isspace(*pos)) pos++;
- if (pos==end || *pos=='#') break;
- for (end2=pos;
- end2<end && !isspace(*end2) && *end2!='#'; end2++);
- switch(field) {
- /* Regex to match this device */
- case 3:
- {
- char *regex=strndupa(pos,end2-pos);
- regex_t match;
- regmatch_t off;
- int result;
-
- /* Is this it? */
- xregcomp(&match,regex,REG_EXTENDED);
- result=regexec(&match,device_name,1,&off,0);
- regfree(&match);
-
- /* If not this device, skip rest of line */
- if(result || off.rm_so
- || off.rm_eo!=strlen(device_name))
- goto end_line;
-
- break;
- }
- /* uid:gid */
- case 2:
- {
- char *s2;
-
- /* Find : */
- for(s=pos;s<end2 && *s!=':';s++);
- if(s==end2) goto end_line;
-
- /* Parse UID */
- uid=strtoul(pos,&s2,10);
- if(s!=s2) {
- struct passwd *pass;
- pass=getpwnam(strndupa(pos,s-pos));
- if(!pass) goto end_line;
- uid=pass->pw_uid;
- }
- s++;
- /* parse GID */
- gid=strtoul(s,&s2,10);
- if(end2!=s2) {
- struct group *grp;
- grp=getgrnam(strndupa(s,end2-s));
- if(!grp) goto end_line;
- gid=grp->gr_gid;
- }
- break;
- }
- /* mode */
- case 1:
- {
- mode=strtoul(pos,&pos,8);
- if(pos!=end2) goto end_line;
- goto found_device;
- }
- }
- pos=end2;
- }
-end_line:
- /* Did everything parse happily? */
- if (field && field!=3)
- bb_error_msg_and_die("Bad line %d",line);
+ /* Determine device name, type, major and minor */
+ device_name = bb_basename(path);
+ /* http://kernel.org/doc/pending/hotplug.txt says that only
+ * "/sys/block/..." is for block devices. "/sys/bus" etc is not.
+ * But since 2.6.25 block devices are also in /sys/class/block.
+ * We use strstr("/block/") to forestall future surprises. */
+ type = S_IFCHR;
+ if (strstr(path, "/block/"))
+ type = S_IFBLK;
+
+#if ENABLE_FEATURE_MDEV_CONF
+ parser = config_open2("/etc/mdev.conf", fopen_for_read);
+
+ /* If we have config file, look up user settings */
+ while (config_read(parser, tokens, 4, 3, "# \t", PARSE_NORMAL)) {
+ regmatch_t off[1 + 9*ENABLE_FEATURE_MDEV_RENAME_REGEXP];
+ char *val;
+
+ /* Fields: regex uid:gid mode [alias] [cmd] */
+
+ /* 1st field: @<numeric maj,min>... */
+ if (tokens[0][0] == '@') {
+ /* @major,minor[-last] */
+ /* (useful when name is ambiguous:
+ * "/sys/class/usb/lp0" and
+ * "/sys/class/printer/lp0") */
+ int cmaj, cmin0, cmin1, sc;
+ if (major < 0)
+ continue; /* no dev, no match */
+ sc = sscanf(tokens[0], "@%u,%u-%u", &cmaj, &cmin0, &cmin1);
+ if (sc < 1 || major != cmaj
+ || (sc == 2 && minor != cmin0)
+ || (sc == 3 && (minor < cmin0 || minor > cmin1))
+ ) {
+ continue; /* no match */
+ }
+ } else { /* ... or regex to match device name */
+ regex_t match;
+ int result;
+
+ /* Is this it? */
+ xregcomp(&match, tokens[0], REG_EXTENDED);
+ result = regexec(&match, device_name, ARRAY_SIZE(off), off, 0);
+ regfree(&match);
+
+ //bb_error_msg("matches:");
+ //for (int i = 0; i < ARRAY_SIZE(off); i++) {
+ // if (off[i].rm_so < 0) continue;
+ // bb_error_msg("match %d: '%.*s'\n", i,
+ // (int)(off[i].rm_eo - off[i].rm_so),
+ // device_name + off[i].rm_so);
+ //}
+
+ /* If not this device, skip rest of line */
+ /* (regexec returns whole pattern as "range" 0) */
+ if (result || off[0].rm_so
+ || ((int)off[0].rm_eo != (int)strlen(device_name))
+ ) {
+ continue;
+ }
+ }
- /* Next line */
- pos=++end;
+ /* This line matches: stop parsing the file
+ * after parsing the rest of fields */
+
+ /* 2nd field: uid:gid - device ownership */
+ parse_chown_usergroup_or_die(&ugid, tokens[1]);
+
+ /* 3rd field: mode - device permissions */
+ mode = strtoul(tokens[2], NULL, 8);
+
+ val = tokens[3];
+ /* 4th field (opt): >alias */
+#if ENABLE_FEATURE_MDEV_RENAME
+ if (!val)
+ break;
+ aliaslink = *val;
+ if (aliaslink == '>' || aliaslink == '=') {
+ char *s;
+#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
+ char *p;
+ unsigned i, n;
+#endif
+ char *a = val;
+ s = strchrnul(val, ' ');
+ val = (s[0] && s[1]) ? s+1 : NULL;
+ s[0] = '\0';
+#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
+ /* substitute %1..9 with off[1..9], if any */
+ n = 0;
+ s = a;
+ while (*s)
+ if (*s++ == '%')
+ n++;
+
+ p = alias = xzalloc(strlen(a) + n * strlen(device_name));
+ s = a + 1;
+ while (*s) {
+ *p = *s;
+ if ('%' == *s) {
+ i = (s[1] - '0');
+ if (i <= 9 && off[i].rm_so >= 0) {
+ n = off[i].rm_eo - off[i].rm_so;
+ strncpy(p, device_name + off[i].rm_so, n);
+ p += n - 1;
+ s++;
+ }
}
-found_device:
- munmap(conf,len);
+ p++;
+ s++;
}
- close(fd);
+#else
+ alias = xstrdup(a + 1);
+#endif
+ }
+#endif /* ENABLE_FEATURE_MDEV_RENAME */
+
+#if ENABLE_FEATURE_MDEV_EXEC
+ /* The rest (opt): command to run */
+ if (!val)
+ break;
+ {
+ const char *s = "@$*";
+ const char *s2 = strchr(s, *val);
+
+ if (!s2)
+ bb_error_msg_and_die("bad line %u", parser->lineno);
+
+ /* Correlate the position in the "@$*" with the delete
+ * step so that we get the proper behavior:
+ * @cmd: run on create
+ * $cmd: run on delete
+ * *cmd: run on both
+ */
+ if ((s2 - s + 1) /*1/2/3*/ & /*1/2*/ (1 + delete)) {
+ command = xstrdup(val + 1);
+ }
+ }
+#endif
+ /* end of field parsing */
+ break; /* we found matching line, stop */
+ } /* end of "while line is read from /etc/mdev.conf" */
+
+ config_close(parser);
+#endif /* ENABLE_FEATURE_MDEV_CONF */
+
+ if (!delete && major >= 0) {
+
+ if (ENABLE_FEATURE_MDEV_RENAME)
+ unlink(device_name);
+
+ if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
+ bb_perror_msg_and_die("mknod %s", device_name);
+
+ if (major == root_major && minor == root_minor)
+ symlink(device_name, "root");
+
+#if ENABLE_FEATURE_MDEV_CONF
+ chown(device_name, ugid.uid, ugid.gid);
+
+#if ENABLE_FEATURE_MDEV_RENAME
+ if (alias) {
+ alias = build_alias(alias, device_name);
+
+ /* move the device, and optionally
+ * make a symlink to moved device node */
+ if (rename(device_name, alias) == 0 && aliaslink == '>')
+ symlink(alias, device_name);
+
+ free(alias);
}
+#endif
+#endif
}
- sprintf(temp, "%s/%s", DEV_PATH, device_name);
- umask(0);
- if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST)
- bb_perror_msg_and_die("mknod %s failed", temp);
+#if ENABLE_FEATURE_MDEV_EXEC
+ if (command) {
+ /* setenv will leak memory, use putenv/unsetenv/free */
+ char *s = xasprintf("MDEV=%s", device_name);
+ putenv(s);
+ if (system(command) == -1)
+ bb_perror_msg_and_die("can't run '%s'", command);
+ unsetenv("MDEV");
+ free(s);
+ free(command);
+ }
+#endif
- if (ENABLE_FEATURE_MDEV_CONF) chown(temp,uid,gid);
-
-end:
- RELEASE_CONFIG_BUFFER(temp);
+ if (delete) {
+ unlink(device_name);
+ /* At creation time, device might have been moved
+ * and a symlink might have been created. Undo that. */
+#if ENABLE_FEATURE_MDEV_RENAME
+ if (alias) {
+ alias = build_alias(alias, device_name);
+ unlink(alias);
+ free(alias);
+ }
+#endif
+ }
}
-/* Recursive search of /sys/block or /sys/class. path must be a writeable
- * buffer of size PATH_MAX containing the directory string to start at. */
+/* File callback for /sys/ traversal */
+static int FAST_FUNC fileAction(const char *fileName,
+ struct stat *statbuf UNUSED_PARAM,
+ void *userData,
+ int depth UNUSED_PARAM)
+{
+ size_t len = strlen(fileName) - 4; /* can't underflow */
+ char *scratch = userData;
+
+ /* len check is for paranoid reasons */
+ if (strcmp(fileName + len, "/dev") != 0 || len >= PATH_MAX)
+ return FALSE;
-static void find_dev(char *path)
+ strcpy(scratch, fileName);
+ scratch[len] = '\0';
+ make_device(scratch, 0);
+
+ return TRUE;
+}
+
+/* Directory callback for /sys/ traversal */
+static int FAST_FUNC dirAction(const char *fileName UNUSED_PARAM,
+ struct stat *statbuf UNUSED_PARAM,
+ void *userData UNUSED_PARAM,
+ int depth)
+{
+ return (depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
+}
+
+/* For the full gory details, see linux/Documentation/firmware_class/README
+ *
+ * Firmware loading works like this:
+ * - kernel sets FIRMWARE env var
+ * - userspace checks /lib/firmware/$FIRMWARE
+ * - userspace waits for /sys/$DEVPATH/loading to appear
+ * - userspace writes "1" to /sys/$DEVPATH/loading
+ * - userspace copies /lib/firmware/$FIRMWARE into /sys/$DEVPATH/data
+ * - userspace writes "0" (worked) or "-1" (failed) to /sys/$DEVPATH/loading
+ * - kernel loads firmware into device
+ */
+static void load_firmware(const char *const firmware, const char *const sysfs_path)
{
- DIR *dir;
- int len=strlen(path);
+ int cnt;
+ int firmware_fd, loading_fd, data_fd;
- if (!(dir = opendir(path)))
- bb_perror_msg_and_die("No %s",path);
+ /* check for /lib/firmware/$FIRMWARE */
+ xchdir("/lib/firmware");
+ firmware_fd = xopen(firmware, O_RDONLY);
- for (;;) {
- struct dirent *entry = readdir(dir);
-
- if (!entry) break;
+ /* in case we goto out ... */
+ data_fd = -1;
- /* Skip "." and ".." (also skips hidden files, which is ok) */
+ /* check for /sys/$DEVPATH/loading ... give 30 seconds to appear */
+ xchdir(sysfs_path);
+ for (cnt = 0; cnt < 30; ++cnt) {
+ loading_fd = open("loading", O_WRONLY);
+ if (loading_fd != -1)
+ goto loading;
+ sleep(1);
+ }
+ goto out;
- if (entry->d_name[0]=='.') continue;
+ loading:
+ /* tell kernel we're loading by `echo 1 > /sys/$DEVPATH/loading` */
+ if (full_write(loading_fd, "1", 1) != 1)
+ goto out;
- if (entry->d_type == DT_DIR) {
- snprintf(path+len, PATH_MAX-len, "/%s", entry->d_name);
- find_dev(path);
- path[len] = 0;
- }
-
- /* If there's a dev entry, mknod it */
-
- if (strcmp(entry->d_name, "dev")) make_device(path);
+ /* load firmware by `cat /lib/firmware/$FIRMWARE > /sys/$DEVPATH/data */
+ data_fd = open("data", O_WRONLY);
+ if (data_fd == -1)
+ goto out;
+ cnt = bb_copyfd_eof(firmware_fd, data_fd);
+
+ /* tell kernel result by `echo [0|-1] > /sys/$DEVPATH/loading` */
+ if (cnt > 0)
+ full_write(loading_fd, "0", 1);
+ else
+ full_write(loading_fd, "-1", 2);
+
+ out:
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ close(firmware_fd);
+ close(loading_fd);
+ close(data_fd);
}
-
- closedir(dir);
}
-int mdev_main(int argc, char *argv[])
+int mdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int mdev_main(int argc UNUSED_PARAM, char **argv)
{
- if (argc > 1) {
- if (argc == 2 && !strcmp(argv[1],"-s")) {
- RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
- strcpy(temp,"/sys/block");
- find_dev(temp);
- strcpy(temp,"/sys/class");
- find_dev(temp);
- if(ENABLE_FEATURE_CLEAN_UP)
- RELEASE_CONFIG_BUFFER(temp);
- return 0;
- } else bb_show_usage();
- }
-
-/* hotplug support goes here */
-
+ RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
+
+ /* We can be called as hotplug helper */
+ /* Kernel cannot provide suitable stdio fds for us, do it ourself */
+#if 1
+ bb_sanitize_stdio();
+#else
+ /* Debug code */
+ /* Replace LOGFILE by other file or device name if you need */
+#define LOGFILE "/dev/console"
+ /* Just making sure fd 0 is not closed,
+ * we don't really intend to read from it */
+ xmove_fd(xopen("/", O_RDONLY), STDIN_FILENO);
+ xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDOUT_FILENO);
+ xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDERR_FILENO);
+#endif
+
+ xchdir("/dev");
+
+ if (argv[1] && !strcmp(argv[1], "-s")) {
+ /* Scan:
+ * mdev -s
+ */
+ struct stat st;
+
+ xstat("/", &st);
+ root_major = major(st.st_dev);
+ root_minor = minor(st.st_dev);
+
+ /* ACTION_FOLLOWLINKS is needed since in newer kernels
+ * /sys/block/loop* (for example) are symlinks to dirs,
+ * not real directories.
+ * (kernel's CONFIG_SYSFS_DEPRECATED makes them real dirs,
+ * but we can't enforce that on users)
+ */
+ if (access("/sys/class/block", F_OK) != 0) {
+ /* Scan obsolete /sys/block only if /sys/class/block
+ * doesn't exist. Otherwise we'll have dupes.
+ */
+ recursive_action("/sys/block",
+ ACTION_RECURSE | ACTION_FOLLOWLINKS,
+ // not needed now? | ACTION_QUIET
+ fileAction, dirAction, temp, 0);
+ }
+ recursive_action("/sys/class",
+ ACTION_RECURSE | ACTION_FOLLOWLINKS,
+ fileAction, dirAction, temp, 0);
+ } else {
+ char *seq;
+ char *action;
+ char *env_path;
+ char seqbuf[sizeof(int)*3 + 2];
+ int seqlen = seqlen; /* for compiler */
+
+ /* Hotplug:
+ * env ACTION=... DEVPATH=... [SEQNUM=...] mdev
+ * ACTION can be "add" or "remove"
+ * DEVPATH is like "/block/sda" or "/class/input/mice"
+ */
+ action = getenv("ACTION");
+ env_path = getenv("DEVPATH");
+ if (!action || !env_path)
+ bb_show_usage();
+
+ seq = getenv("SEQNUM");
+ if (seq) {
+ int timeout = 2000 / 32;
+ do {
+ seqlen = open_read_close("mdev.seq", seqbuf, sizeof(seqbuf-1));
+ if (seqlen < 0)
+ break;
+ seqbuf[seqlen] = '\0';
+ if (seqbuf[0] == '\n' /* seed file? */
+ || strcmp(seq, seqbuf) == 0 /* correct idx? */
+ ) {
+ break;
+ }
+ usleep(32*1000);
+ } while (--timeout);
+ }
+
+ snprintf(temp, PATH_MAX, "/sys%s", env_path);
+ if (!strcmp(action, "remove"))
+ make_device(temp, 1);
+ else if (!strcmp(action, "add")) {
+ make_device(temp, 0);
+
+ if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
+ char *fw = getenv("FIRMWARE");
+ if (fw)
+ load_firmware(fw, temp);
+ }
+ }
+
+ if (seq && seqlen >= 0) {
+ xopen_xwrite_close("mdev.seq", utoa(xatou(seq) + 1));
+ }
+ }
+
+ if (ENABLE_FEATURE_CLEAN_UP)
+ RELEASE_CONFIG_BUFFER(temp);
+
return 0;
}
projects / oweals / busybox.git / blobdiff