| /* |
| * blockdev implementation for busybox |
| * |
| * Copyright (C) 2010 Sergey Naumov <sknaumov@gmail.com> |
| * |
| * Licensed under GPLv2, see file LICENSE in this source tree. |
| */ |
| |
| //applet:IF_BLOCKDEV(APPLET(blockdev, _BB_DIR_SBIN, _BB_SUID_DROP)) |
| |
| //kbuild:lib-$(CONFIG_BLOCKDEV) += blockdev.o |
| |
| //config:config BLOCKDEV |
| //config: bool "blockdev" |
| //config: default y |
| //config: help |
| //config: Performs some ioctls with block devices. |
| |
| //usage:#define blockdev_trivial_usage |
| //usage: "OPTION BLOCKDEV" |
| //usage:#define blockdev_full_usage "\n\n" |
| //usage: "Options:" |
| //usage: "\n --setro Set ro" |
| //usage: "\n --setrw Set rw" |
| //usage: "\n --getro Get ro" |
| //usage: "\n --getss Get sector size" |
| //usage: "\n --getbsz Get block size" |
| //usage: "\n --setbsz BYTES Set block size" |
| //usage: "\n --getsize Get device size in 512-byte sectors" |
| //usage: "\n --getsize64 Get device size in bytes" |
| //usage: "\n --flushbufs Flush buffers" |
| //usage: "\n --rereadpt Reread partition table" |
| |
| |
| #include "libbb.h" |
| #include <linux/fs.h> |
| |
| enum { |
| ARG_NONE = 0, |
| ARG_INT = 1, |
| ARG_ULONG = 2, |
| /* Yes, BLKGETSIZE64 takes pointer to uint64_t, not ullong! */ |
| ARG_U64 = 3, |
| ARG_MASK = 3, |
| |
| FL_USRARG = 4, /* argument is provided by user */ |
| FL_NORESULT = 8, |
| }; |
| |
| struct bdc { |
| uint32_t ioc; /* ioctl code */ |
| const char name[sizeof("flushbufs")]; /* "--setfoo" wothout "--" */ |
| uint8_t flags; |
| int8_t argval; /* default argument value */ |
| }; |
| |
| static const struct bdc bdcommands[] = { |
| { |
| .ioc = BLKROSET, |
| .name = "setro", |
| .flags = ARG_INT + FL_NORESULT, |
| .argval = 1, |
| },{ |
| .ioc = BLKROSET, |
| .name = "setrw", |
| .flags = ARG_INT + FL_NORESULT, |
| .argval = 0, |
| },{ |
| .ioc = BLKROGET, |
| .name = "getro", |
| .flags = ARG_INT, |
| .argval = -1, |
| },{ |
| .ioc = BLKSSZGET, |
| .name = "getss", |
| .flags = ARG_INT, |
| .argval = -1, |
| },{ |
| .ioc = BLKBSZGET, |
| .name = "getbsz", |
| .flags = ARG_INT, |
| .argval = -1, |
| },{ |
| .ioc = BLKBSZSET, |
| .name = "setbsz", |
| .flags = ARG_INT + FL_NORESULT + FL_USRARG, |
| .argval = 0, |
| },{ |
| .ioc = BLKGETSIZE, |
| .name = "getsize", |
| .flags = ARG_ULONG, |
| .argval = -1, |
| },{ |
| .ioc = BLKGETSIZE64, |
| .name = "getsize64", |
| .flags = ARG_U64, |
| .argval = -1, |
| },{ |
| .ioc = BLKFLSBUF, |
| .name = "flushbufs", |
| .flags = ARG_NONE + FL_NORESULT, |
| .argval = 0, |
| },{ |
| .ioc = BLKRRPART, |
| .name = "rereadpt", |
| .flags = ARG_NONE + FL_NORESULT, |
| .argval = 0, |
| } |
| }; |
| |
| static const struct bdc *find_cmd(const char *s) |
| { |
| const struct bdc *bdcmd = bdcommands; |
| if (s[0] == '-' && s[1] == '-') { |
| s += 2; |
| do { |
| if (strcmp(s, bdcmd->name) == 0) |
| return bdcmd; |
| bdcmd++; |
| } while (bdcmd != bdcommands + ARRAY_SIZE(bdcommands)); |
| } |
| bb_show_usage(); |
| } |
| |
| int blockdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int blockdev_main(int argc, char **argv) |
| { |
| const struct bdc *bdcmd; |
| int fd; |
| uint64_t u64; |
| union { |
| int i; |
| unsigned long lu; |
| uint64_t u64; |
| } ioctl_val_on_stack; |
| |
| if ((unsigned)(argc - 3) > 1) /* must have 2 or 3 args */ |
| bb_show_usage(); |
| |
| bdcmd = find_cmd(*++argv); |
| |
| u64 = (int)bdcmd->argval; |
| if (bdcmd->flags & FL_USRARG) |
| u64 = xatoi_positive(*++argv); |
| |
| if (!*++argv || argv[1]) |
| bb_show_usage(); |
| fd = xopen(*argv, O_RDONLY); |
| |
| ioctl_val_on_stack.u64 = u64; |
| #if BB_BIG_ENDIAN |
| /* Store data properly wrt data size. |
| * (1) It's no-op for little-endian. |
| * (2) it's no-op for 0 and -1. Only --setro uses arg != 0 and != -1, |
| * and it is ARG_INT. --setbsz USER_VAL is also ARG_INT. |
| * Thus, we don't need to handle ARG_ULONG. |
| */ |
| switch (bdcmd->flags & ARG_MASK) { |
| case ARG_INT: |
| ioctl_val_on_stack.i = (int)u64; |
| break; |
| # if 0 /* unused */ |
| case ARG_ULONG: |
| ioctl_val_on_stack.lu = (unsigned long)u64; |
| break; |
| # endif |
| } |
| #endif |
| |
| if (ioctl(fd, bdcmd->ioc, &ioctl_val_on_stack.u64) == -1) |
| bb_simple_perror_msg_and_die(*argv); |
| |
| /* Fetch it into register(s) */ |
| u64 = ioctl_val_on_stack.u64; |
| |
| /* Zero- or one-extend the value if needed, then print */ |
| switch (bdcmd->flags & (ARG_MASK+FL_NORESULT)) { |
| case ARG_INT: |
| /* Smaller code when we use long long |
| * (gcc tail-merges printf call) |
| */ |
| printf("%lld\n", (long long)(int)u64); |
| break; |
| case ARG_ULONG: |
| u64 = (unsigned long)u64; |
| /* FALLTHROUGH */ |
| case ARG_U64: |
| printf("%llu\n", (unsigned long long)u64); |
| break; |
| } |
| |
| if (ENABLE_FEATURE_CLEAN_UP) |
| close(fd); |
| return EXIT_SUCCESS; |
| } |