/* vi:set 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. */ #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 <stdlib.h> #include "busybox.h" #include "xregex.h" #define DEV_PATH "/dev" #include <busybox.h> /* mknod in /dev based on a path like "/sys/block/hda/hda1" */ static void make_device(char *path) { 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; close(fd); /* Determine device name, type, major and minor */ device_name = strrchr(path, '/') + 1; type = strncmp(path+5, "block/" ,6) ? S_IFCHR : S_IFBLK; if(sscanf(temp, "%d:%d", &major, &minor) != 2) goto end; /* 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); /* Next line */ pos=++end; } found_device: munmap(conf,len); } close(fd); } } 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_CONF) chown(temp,uid,gid); end: RELEASE_CONFIG_BUFFER(temp); } /* 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. */ static void find_dev(char *path) { DIR *dir; int len=strlen(path); if (!(dir = opendir(path))) bb_perror_msg_and_die("No %s",path); for (;;) { struct dirent *entry = readdir(dir); if (!entry) break; /* Skip "." and ".." (also skips hidden files, which is ok) */ if (entry->d_name[0]=='.') continue; 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); } closedir(dir); } int mdev_main(int argc, char *argv[]) { char *action; char *env_path; RESERVE_CONFIG_BUFFER(temp,PATH_MAX); /* Scan */ if (argc == 2 && !strcmp(argv[1],"-s")) { strcpy(temp,"/sys/block"); find_dev(temp); strcpy(temp,"/sys/class"); find_dev(temp); /* Hotplug */ } else { action = getenv("ACTION"); env_path = getenv("DEVPATH"); if (!action || !env_path) bb_show_usage(); if (!strcmp(action, "add")) { sprintf(temp, "/sys%s", env_path); make_device(temp); } else if (!strcmp(action, "remove")) { sprintf(temp, "%s/%s", DEV_PATH, strrchr(env_path, '/') + 1); unlink(temp); } } if(ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp); return 0; }