[1770] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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[821] | 3 | *
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| 4 | * mdev - Mini udev for busybox
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| 5 | *
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| 6 | * Copyright 2005 Rob Landley <rob@landley.net>
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| 7 | * Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
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| 8 | *
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[1770] | 9 | * Licensed under GPL version 2, see file LICENSE in this tarball for details.
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[821] | 10 | */
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| 11 |
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[1770] | 12 | #include "libbb.h"
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[821] | 13 | #include "xregex.h"
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| 14 |
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[1770] | 15 | struct globals {
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[821] | 16 | int root_major, root_minor;
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[1770] | 17 | };
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| 18 | #define G (*(struct globals*)&bb_common_bufsiz1)
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| 19 | #define root_major (G.root_major)
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| 20 | #define root_minor (G.root_minor)
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[821] | 21 |
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[1770] | 22 | #define MAX_SYSFS_DEPTH 3 /* prevent infinite loops in /sys symlinks */
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[821] | 23 |
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| 24 | /* mknod in /dev based on a path like "/sys/block/hda/hda1" */
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| 25 | static void make_device(char *path, int delete)
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| 26 | {
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[1770] | 27 | const char *device_name;
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| 28 | int major, minor, type, len;
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[821] | 29 | int mode = 0660;
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| 30 | uid_t uid = 0;
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| 31 | gid_t gid = 0;
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| 32 | char *temp = path + strlen(path);
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| 33 | char *command = NULL;
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| 34 |
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| 35 | /* Try to read major/minor string. Note that the kernel puts \n after
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| 36 | * the data, so we don't need to worry about null terminating the string
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| 37 | * because sscanf() will stop at the first nondigit, which \n is. We
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| 38 | * also depend on path having writeable space after it. */
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| 39 |
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[902] | 40 | if (!delete) {
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| 41 | strcat(path, "/dev");
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[1770] | 42 | len = open_read_close(path, temp + 1, 64);
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[902] | 43 | *temp++ = 0;
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| 44 | if (len < 1) return;
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| 45 | }
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[821] | 46 |
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| 47 | /* Determine device name, type, major and minor */
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| 48 |
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[1770] | 49 | device_name = bb_basename(path);
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[821] | 50 | type = path[5]=='c' ? S_IFCHR : S_IFBLK;
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| 51 |
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| 52 | /* If we have a config file, look up permissions for this device */
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| 53 |
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| 54 | if (ENABLE_FEATURE_MDEV_CONF) {
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| 55 | char *conf, *pos, *end;
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[1770] | 56 | int line, fd;
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[821] | 57 |
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| 58 | /* mmap the config file */
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[1770] | 59 | fd = open("/etc/mdev.conf", O_RDONLY);
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| 60 | if (fd < 0)
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| 61 | goto end_parse;
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| 62 | len = xlseek(fd, 0, SEEK_END);
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| 63 | conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
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| 64 | close(fd);
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| 65 | if (!conf)
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| 66 | goto end_parse;
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[821] | 67 |
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[1770] | 68 | line = 0;
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| 69 | /* Loop through lines in mmaped file*/
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| 70 | for (pos=conf; pos-conf<len;) {
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| 71 | int field;
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| 72 | char *end2;
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[821] | 73 |
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[1770] | 74 | line++;
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| 75 | /* find end of this line */
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| 76 | for (end=pos; end-conf<len && *end!='\n'; end++)
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| 77 | ;
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[821] | 78 |
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[1770] | 79 | /* Three fields: regex, uid:gid, mode */
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| 80 | for (field=0; field < (3 + ENABLE_FEATURE_MDEV_EXEC);
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| 81 | field++)
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| 82 | {
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| 83 | /* Skip whitespace */
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| 84 | while (pos<end && isspace(*pos)) pos++;
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| 85 | if (pos==end || *pos=='#') break;
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| 86 | for (end2=pos;
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| 87 | end2<end && !isspace(*end2) && *end2!='#'; end2++)
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| 88 | ;
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[821] | 89 |
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[1770] | 90 | if (field == 0) {
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| 91 | /* Regex to match this device */
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[821] | 92 |
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[1770] | 93 | char *regex = xstrndup(pos, end2-pos);
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| 94 | regex_t match;
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| 95 | regmatch_t off;
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| 96 | int result;
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[821] | 97 |
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[1770] | 98 | /* Is this it? */
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| 99 | xregcomp(&match,regex, REG_EXTENDED);
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| 100 | result = regexec(&match, device_name, 1, &off, 0);
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| 101 | regfree(&match);
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| 102 | free(regex);
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[821] | 103 |
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[1770] | 104 | /* If not this device, skip rest of line */
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| 105 | if (result || off.rm_so
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| 106 | || off.rm_eo != strlen(device_name))
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| 107 | break;
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| 108 | }
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| 109 | if (field == 1) {
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| 110 | /* uid:gid */
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[821] | 111 |
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[1770] | 112 | char *s, *s2;
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[821] | 113 |
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[1770] | 114 | /* Find : */
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| 115 | for (s=pos; s<end2 && *s!=':'; s++)
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| 116 | ;
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| 117 | if (s == end2) break;
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[821] | 118 |
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[1770] | 119 | /* Parse UID */
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| 120 | uid = strtoul(pos, &s2, 10);
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| 121 | if (s != s2) {
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| 122 | struct passwd *pass;
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| 123 | char *_unam = xstrndup(pos, s-pos);
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| 124 | pass = getpwnam(_unam);
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| 125 | free(_unam);
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| 126 | if (!pass) break;
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| 127 | uid = pass->pw_uid;
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| 128 | }
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| 129 | s++;
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| 130 | /* parse GID */
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| 131 | gid = strtoul(s, &s2, 10);
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| 132 | if (end2 != s2) {
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| 133 | struct group *grp;
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| 134 | char *_grnam = xstrndup(s, end2-s);
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| 135 | grp = getgrnam(_grnam);
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| 136 | free(_grnam);
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| 137 | if (!grp) break;
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| 138 | gid = grp->gr_gid;
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| 139 | }
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| 140 | }
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| 141 | if (field == 2) {
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| 142 | /* mode */
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[821] | 143 |
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[1770] | 144 | mode = strtoul(pos, &pos, 8);
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| 145 | if (pos != end2) break;
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| 146 | }
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| 147 | if (ENABLE_FEATURE_MDEV_EXEC && field == 3) {
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| 148 | // Command to run
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| 149 | const char *s = "@$*";
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| 150 | const char *s2;
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| 151 | s2 = strchr(s, *pos++);
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| 152 | if (!s2) {
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| 153 | // Force error
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| 154 | field = 1;
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| 155 | break;
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| 156 | }
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| 157 | if ((s2-s+1) & (1<<delete))
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| 158 | command = xstrndup(pos, end-pos);
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| 159 | }
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[821] | 160 |
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[1770] | 161 | pos = end2;
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| 162 | }
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[821] | 163 |
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[1770] | 164 | /* Did everything parse happily? */
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[821] | 165 |
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[1770] | 166 | if (field > 2) break;
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| 167 | if (field) bb_error_msg_and_die("bad line %d",line);
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[821] | 168 |
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[1770] | 169 | /* Next line */
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| 170 | pos = ++end;
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[821] | 171 | }
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[1770] | 172 | munmap(conf, len);
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| 173 | end_parse: /* nothing */ ;
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[821] | 174 | }
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| 175 |
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| 176 | umask(0);
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| 177 | if (!delete) {
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[902] | 178 | if (sscanf(temp, "%d:%d", &major, &minor) != 2) return;
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[821] | 179 | if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
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[1770] | 180 | bb_perror_msg_and_die("mknod %s", device_name);
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[821] | 181 |
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[1770] | 182 | if (major == root_major && minor == root_minor)
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[821] | 183 | symlink(device_name, "root");
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[1770] | 184 |
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[821] | 185 | if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid);
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| 186 | }
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| 187 | if (command) {
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[1770] | 188 | /* setenv will leak memory, so use putenv */
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| 189 | char *s = xasprintf("MDEV=%s", device_name);
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[821] | 190 | putenv(s);
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[1770] | 191 | if (system(command) == -1)
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| 192 | bb_perror_msg_and_die("cannot run %s", command);
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| 193 | s[4] = '\0';
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| 194 | unsetenv(s);
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[821] | 195 | free(s);
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| 196 | free(command);
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| 197 | }
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| 198 | if (delete) unlink(device_name);
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| 199 | }
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| 200 |
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[1770] | 201 | /* File callback for /sys/ traversal */
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| 202 | static int fileAction(const char *fileName, struct stat *statbuf,
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| 203 | void *userData, int depth)
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| 204 | {
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| 205 | size_t len = strlen(fileName) - 4;
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| 206 | char *scratch = userData;
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[821] | 207 |
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[1770] | 208 | if (strcmp(fileName + len, "/dev"))
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| 209 | return FALSE;
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| 210 |
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| 211 | strcpy(scratch, fileName);
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| 212 | scratch[len] = 0;
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| 213 | make_device(scratch, 0);
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| 214 |
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| 215 | return TRUE;
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| 216 | }
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| 217 |
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| 218 | /* Directory callback for /sys/ traversal */
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| 219 | static int dirAction(const char *fileName, struct stat *statbuf,
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| 220 | void *userData, int depth)
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[821] | 221 | {
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[1770] | 222 | return (depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
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| 223 | }
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[821] | 224 |
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[1770] | 225 | /* For the full gory details, see linux/Documentation/firmware_class/README
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| 226 | *
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| 227 | * Firmware loading works like this:
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| 228 | * - kernel sets FIRMWARE env var
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| 229 | * - userspace checks /lib/firmware/$FIRMWARE
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| 230 | * - userspace waits for /sys/$DEVPATH/loading to appear
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| 231 | * - userspace writes "1" to /sys/$DEVPATH/loading
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| 232 | * - userspace copies /lib/firmware/$FIRMWARE into /sys/$DEVPATH/data
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| 233 | * - userspace writes "0" (worked) or "-1" (failed) to /sys/$DEVPATH/loading
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| 234 | * - kernel loads firmware into device
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| 235 | */
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| 236 | static void load_firmware(const char *const firmware, const char *const sysfs_path)
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| 237 | {
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| 238 | int cnt;
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| 239 | int firmware_fd, loading_fd, data_fd;
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[821] | 240 |
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[1770] | 241 | /* check for $FIRMWARE from kernel */
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| 242 | /* XXX: dont bother: open(NULL) works same as open("no-such-file")
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| 243 | * if (!firmware)
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| 244 | * return;
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| 245 | */
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[821] | 246 |
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[1770] | 247 | /* check for /lib/firmware/$FIRMWARE */
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| 248 | xchdir("/lib/firmware");
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| 249 | firmware_fd = xopen(firmware, O_RDONLY);
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[821] | 250 |
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[1770] | 251 | /* in case we goto out ... */
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| 252 | data_fd = -1;
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[821] | 253 |
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[1770] | 254 | /* check for /sys/$DEVPATH/loading ... give 30 seconds to appear */
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| 255 | xchdir(sysfs_path);
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| 256 | for (cnt = 0; cnt < 30; ++cnt) {
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| 257 | loading_fd = open("loading", O_WRONLY);
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| 258 | if (loading_fd == -1)
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| 259 | sleep(1);
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| 260 | else
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| 261 | break;
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| 262 | }
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| 263 | if (loading_fd == -1)
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| 264 | goto out;
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[821] | 265 |
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[1770] | 266 | /* tell kernel we're loading by `echo 1 > /sys/$DEVPATH/loading` */
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| 267 | if (write(loading_fd, "1", 1) != 1)
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| 268 | goto out;
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[821] | 269 |
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[1770] | 270 | /* load firmware by `cat /lib/firmware/$FIRMWARE > /sys/$DEVPATH/data */
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| 271 | data_fd = open("data", O_WRONLY);
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| 272 | if (data_fd == -1)
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| 273 | goto out;
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| 274 | cnt = bb_copyfd_eof(firmware_fd, data_fd);
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[821] | 275 |
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[1770] | 276 | /* tell kernel result by `echo [0|-1] > /sys/$DEVPATH/loading` */
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| 277 | if (cnt > 0)
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| 278 | write(loading_fd, "0", 1);
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| 279 | else
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| 280 | write(loading_fd, "-1", 2);
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| 281 |
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| 282 | out:
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| 283 | if (ENABLE_FEATURE_CLEAN_UP) {
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| 284 | close(firmware_fd);
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| 285 | close(loading_fd);
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| 286 | close(data_fd);
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[821] | 287 | }
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| 288 | }
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| 289 |
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[1770] | 290 | int mdev_main(int argc, char **argv);
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| 291 | int mdev_main(int argc, char **argv)
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[821] | 292 | {
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| 293 | char *action;
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| 294 | char *env_path;
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| 295 | RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
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| 296 |
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[1770] | 297 | xchdir("/dev");
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[821] | 298 |
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| 299 | /* Scan */
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| 300 |
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| 301 | if (argc == 2 && !strcmp(argv[1],"-s")) {
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| 302 | struct stat st;
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| 303 |
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[1770] | 304 | xstat("/", &st);
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| 305 | root_major = major(st.st_dev);
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| 306 | root_minor = minor(st.st_dev);
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[821] | 307 |
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[1770] | 308 | recursive_action("/sys/block",
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| 309 | ACTION_RECURSE | ACTION_FOLLOWLINKS,
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| 310 | fileAction, dirAction, temp, 0);
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| 311 |
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| 312 | recursive_action("/sys/class",
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| 313 | ACTION_RECURSE | ACTION_FOLLOWLINKS,
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| 314 | fileAction, dirAction, temp, 0);
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| 315 |
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[821] | 316 | /* Hotplug */
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| 317 |
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| 318 | } else {
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| 319 | action = getenv("ACTION");
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| 320 | env_path = getenv("DEVPATH");
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[1770] | 321 | if (!action || !env_path)
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[821] | 322 | bb_show_usage();
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| 323 |
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| 324 | sprintf(temp, "/sys%s", env_path);
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[1770] | 325 | if (!strcmp(action, "remove"))
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| 326 | make_device(temp, 1);
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| 327 | else if (!strcmp(action, "add")) {
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| 328 | make_device(temp, 0);
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| 329 |
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| 330 | if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE)
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| 331 | load_firmware(getenv("FIRMWARE"), temp);
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| 332 | }
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[821] | 333 | }
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| 334 |
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| 335 | if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);
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| 336 | return 0;
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| 337 | }
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