1 files changed, 195 insertions, 0 deletions

diff --git a/util-linux/blockdev.c b/util-linux/blockdev.c
new file mode 100644
index 000000000..c61116df9
--- /dev/null
+++ b/util-linux/blockdev.c
@@ -0,0 +1,195 @@
+/*
+ * 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;
+}