ubi-utils: allow 'ubiformat' to read from stdin

This patch allows to read the image from stdin and adds an
'--image-size' option to specify its size.  'upiupdatevol' has this
feature already and it is useful for 'ubiformat' too.

It adds a read_all() function which reads a block of data. Plain
'read(2)' can fail on

  nc -l -p 1234 | ubiformat -f - -S 25427968

else.

Signed-off-by: Enrico Scholz <enrico.scholz@sigma-chemnitz.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

diff --git a/ubi-utils/new-utils/src/ubiformat.c b/ubi-utils/new-utils/src/ubiformat.c
index c2888e0a75898a0f645b10f780ac7df237513426..05caed98d5dd384308ba011ac26fff244ab3e88a 100644 (file)
--- a/ubi-utils/new-utils/src/ubiformat.c
+++ b/ubi-utils/new-utils/src/ubiformat.c
@@ -51,6 +51,7 @@ struct args {
        int subpage_size;
        int vid_hdr_offs;
        int ubi_ver;
+       off_t image_sz;
        long long ec;
        const char *image;
        const char *node;
@@ -62,7 +63,7 @@ static struct args args =
 };
 
 static const char *doc = PROGRAM_NAME " version " PROGRAM_VERSION
-                " - a tool to format MTD devices and flash UBI images";
+               " - a tool to format MTD devices and flash UBI images";
 
 static const char *optionsstr =
 "-s, --sub-page-size=<bytes>  minimum input/output unit used for UBI\n"
@@ -75,7 +76,8 @@ static const char *optionsstr =
 "                             header)\n"
 "-n, --no-volume-table        only erase all eraseblock and preserve erase\n"
 "                             counters, do not write empty volume table\n"
-"-f, --flash-image=<file>     flash image file\n"
+"-f, --flash-image=<file>     flash image file, or '-' for stdin\n"
+"-S, --image-size=<bytes>     bytes in input, if not reading from file\n"
 "-e, --erase-counter=<value>  use <value> as the erase counter value for all\n"
 "                             eraseblocks\n"
 "-y, --yes                    assume the answer is \"yes\" for all question\n"
@@ -93,7 +95,7 @@ static const char *usage =
 "\t\t\t[--help] [--version] [--yes] [--verbose] [--quiet]\n"
 "\t\t\t[--ec=<value>] [--vid-hdr-offset=<offs>]\n"
 "\t\t\t[--ubi-ver=<num>] [--no-volume-table]\n"
-"\t\t\t[--flash-image=<file>]\n\n"
+"\t\t\t[--flash-image=<file>] [--image-size=<bytes>]\n\n"
 
 "Example 1: " PROGRAM_NAME " /dev/mtd0 -y - format MTD device number 0 and do\n"
 "           not ask questions.\n"
@@ -105,6 +107,7 @@ static const struct option long_options[] = {
        { .name = "vid-hdr-offset",  .has_arg = 1, .flag = NULL, .val = 'O' },
        { .name = "no-volume-table", .has_arg = 0, .flag = NULL, .val = 'n' },
        { .name = "flash-image",     .has_arg = 1, .flag = NULL, .val = 'f' },
+       { .name = "image-size",      .has_arg = 1, .flag = NULL, .val = 'S' },
        { .name = "yes",             .has_arg = 0, .flag = NULL, .val = 'y' },
        { .name = "erase-counter",   .has_arg = 1, .flag = NULL, .val = 'e' },
        { .name = "quiet",           .has_arg = 0, .flag = NULL, .val = 'q' },
@@ -121,7 +124,7 @@ static int parse_opt(int argc, char * const argv[])
                int key;
                char *endp;
 
-               key = getopt_long(argc, argv, "nh?Vyqve:x:s:O:f:", long_options, NULL);
+               key = getopt_long(argc, argv, "nh?Vyqve:x:s:O:f:S:", long_options, NULL);
                if (key == -1)
                        break;
 
@@ -153,6 +156,12 @@ static int parse_opt(int argc, char * const argv[])
                        args.image = optarg;
                        break;
 
+               case 'S':
+                       args.image_sz = ubiutils_get_bytes(optarg);
+                       if (args.image_sz <= 0)
+                               return errmsg("bad image-size: \"%s\"", optarg);
+                       break;
+
                case 'n':
                        args.novtbl = 1;
                        break;
@@ -284,7 +293,7 @@ static int drop_ffs(const struct mtd_info *mtd, const void *buf, int len)
        int i;
 
         for (i = len - 1; i >= 0; i--)
-              if (((const uint8_t *)buf)[i] != 0xFF)
+               if (((const uint8_t *)buf)[i] != 0xFF)
                      break;
 
         /* The resulting length must be aligned to the minimum flash I/O size */
@@ -294,27 +303,75 @@ static int drop_ffs(const struct mtd_info *mtd, const void *buf, int len)
         return len;
 }
 
+static int open_file(const struct mtd_info *mtd, struct ubi_scan_info *si,
+                    off_t *sz)
+{
+       int fd;
+
+       if (!strcmp(args.image, "-")) {
+               if (args.image_sz == 0)
+                       return errmsg("must use '-S' with non-zero value when reading from stdin");
+
+               *sz = args.image_sz;
+               fd  = dup(STDIN_FILENO);
+               if (fd < 0)
+                       return sys_errmsg("failed to dup stdin");
+       } else {
+               struct stat st;
+
+               if (stat(args.image, &st))
+                       return sys_errmsg("cannot open \"%s\"", args.image);
+
+               *sz = st.st_size;
+               fd  = open(args.image, O_RDONLY);
+               if (fd == -1)
+                       return sys_errmsg("cannot open \"%s\"", args.image);
+       }
+
+       return fd;
+}
+
+static int read_all(int fd, void *buf, size_t len)
+{
+       while (len > 0) {
+               ssize_t l = read(fd, buf, len);
+               if (l == 0)
+                       return errmsg("eof reached; %d bytes remaining", len);
+               else if (l > 0) {
+                       buf += l;
+                       len -= l;
+               } else if (errno == EINTR || errno == EAGAIN)
+                       continue;
+               else
+                       return sys_errmsg("reading failed; %d bytes remaining", len);
+       }
+
+       return 0;
+}
+
 static int flash_image(const struct mtd_info *mtd, const struct ubigen_info *ui,
                       struct ubi_scan_info *si)
 {
        int fd, img_ebs, eb, written_ebs = 0, divisor;
-       struct stat st;
+       off_t st_size;
 
-       if (stat(args.image, &st))
-               return sys_errmsg("cannot open \"%s\"", args.image);
+       fd = open_file(mtd, si, &st_size);
+       if (fd < 0)
+               return fd;
 
-       img_ebs = st.st_size / mtd->eb_size;
-       if (img_ebs > si->good_cnt)
-               return sys_errmsg("file \"%s\" is too large (%lld bytes)",
-                                 args.image, (long long)st.st_size);
+       img_ebs = st_size / mtd->eb_size;
 
-       if (st.st_size % mtd->eb_size)
-               return sys_errmsg("file \"%s\" (size %lld bytes) is not multiple of eraseblock size (%d bytes)",
-                                 args.image, (long long)st.st_size, mtd->eb_size);
+       if (img_ebs > si->good_cnt) {
+               sys_errmsg("file \"%s\" is too large (%lld bytes)",
+                          args.image, (long long)st_size);
+               goto out_close;
+       }
 
-       fd = open(args.image, O_RDONLY);
-       if (fd == -1)
-               return sys_errmsg("cannot open \"%s\"", args.image);
+       if (st_size % mtd->eb_size) {
+               return sys_errmsg("file \"%s\" (size %lld bytes) is not multiple of eraseblock size (%d bytes)",
+                                 args.image, (long long)st_size, mtd->eb_size);
+               goto out_close;
+       }
 
        verbose(args.verbose, "will write %d eraseblocks", img_ebs);
        divisor = img_ebs;
@@ -345,7 +402,8 @@ static int flash_image(const struct mtd_info *mtd, const struct ubigen_info *ui,
                        goto out_close;
                }
 
-               if (read(fd, buf, mtd->eb_size) != mtd->eb_size) {
+               err = read_all(fd, buf, mtd->eb_size);
+               if (err) {
                        sys_errmsg("failed to read eraseblock %d from \"%s\"",
                                   written_ebs, args.image);
                        goto out_close;