From: Mark Wooding <mdw@distorted.org.uk>
Date: Wed, 16 Feb 2022 21:13:46 +0000 (+0000)
Subject: dvd-sector-copy.c: Hoist out the common sector-range parsing machinery.
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/dvdrip/commitdiff_plain/87a145d259478ae7d7dcc789d368b8fa3566f323

dvd-sector-copy.c: Hoist out the common sector-range parsing machinery.
---

diff --git a/dvd-sector-copy.c b/dvd-sector-copy.c
index dceab3f..a43adb2 100644
--- a/dvd-sector-copy.c
+++ b/dvd-sector-copy.c
@@ -152,6 +152,7 @@ static void store_filename(char *buf, ident id)
 
 typedef uint_least32_t secaddr;
 #define PRIuSEC PRIuLEAST32
+#define SECLIMIT 0x00400000
 
 #define MAXFILES (1 + 2*99 + 1)
 struct file {
@@ -595,6 +596,49 @@ static int read_line(FILE *fp, struct buf *b)
   return (0);
 }
 
+#define PRF_HYPHEN 1u
+static int parse_range(const char *p, unsigned f,
+		       secaddr *start_out, secaddr *end_out)
+{
+  char *q;
+  int err, rc;
+  unsigned long start, end;
+
+  err = errno;
+
+  if (ISDIGIT(*p)) {
+    start = strtoul(p, &q, 0);
+    if (errno || start >= SECLIMIT) { rc = -1; goto end; }
+    *start_out = start; p = q;
+  } else if (!(f&PRF_HYPHEN))
+    { rc = -1; goto end; }
+  else
+    start = 0;
+
+  if (f&PRF_HYPHEN) {
+    if (*p != '-')  { rc = -1; goto end; }
+    p++;
+  } else {
+    if (!ISSPACE(*p)) { rc = -1; goto end; }
+    do p++; while (ISSPACE(*p));
+  }
+
+  if (ISDIGIT(*p)) {
+    end = strtoul(p, &q, 0);
+    if (errno || end > SECLIMIT || end < start) { rc = -1; goto end; }
+    *end_out = end; p = q;
+  } else if (!(f&PRF_HYPHEN))
+    { rc = -1; goto end; }
+
+  if (!(f&PRF_HYPHEN)) while (ISSPACE(*p)) p++;
+  if (*p) { rc = -1; goto end; }
+
+  rc = 0;
+end:
+  errno = err;
+  return (rc);
+}
+
 int main(int argc, char *argv[])
 {
   unsigned f = 0;
@@ -602,7 +646,7 @@ int main(int argc, char *argv[])
   uint64_t volsz;
   secaddr pos;
   off_t off;
-  unsigned long start, end;
+  secaddr start, end;
   const struct event *ev;
   const char *device = "/dev/dvd", *outfile = 0;
   int opt, blksz;
@@ -638,16 +682,9 @@ int main(int argc, char *argv[])
 	  p = buf.p; i++;
 	  while (ISSPACE(*p)) p++;
 	  if (!*p || *p == '#') continue;
-	  if (!ISDIGIT(*p)) goto bad_range_file;
-	  start = strtoul(p, &p, 0);
-	  if (errno || !ISSPACE(*p)) goto bad_range_file;
-	  do p++; while (ISSPACE(*p));
-	  if (!ISDIGIT(*p)) goto bad_range_file;
-	  end = strtoul(p, &p, 0);
-	  if (errno || (*p && !ISSPACE(*p))) goto bad_range_file;
-	  while (ISSPACE(*p)) p++;
-	  if (*p) goto bad_range_file;
-	  if (start > end) goto bad_range_file;
+	  if (parse_range(p, 0, &start, &end) ||
+	      (last <= SECLIMIT && start < last))
+	    bail("bad range `%s' at `%s' line %zu", buf.p, optarg, i);
 	  if (start < end) {
 	    put_event(EV_WRITE, 0, start);
 	    put_event(EV_STOP, 0, end);
@@ -656,8 +693,6 @@ int main(int argc, char *argv[])
 	if (ferror(fp))
 	  bail_syserr(errno, "failed to read ranges file `%s'", optarg);
 	break;
-      bad_range_file:
-	bail("bad range `%s' at `%s' line %zu", buf.p, optarg, i);
       case 'b':
 	if (mapfile) bail("can't have multiple map files");
 	mapfile = optarg;
@@ -665,32 +700,13 @@ int main(int argc, char *argv[])
       case 'c': f |= f_continue; break;
       case 'o': outfile = optarg; break;
       case 'r':
-	err = errno; errno = 0;
-	p = optarg;
-	if (*p == '-')
-	  start = 0;
-	else {
-	  if (!ISDIGIT(*p)) goto bad_range;
-	  start = strtoul(p, &p, 0);
-	  if (errno || *p != '-') goto bad_range;
-	}
-	p++;
-	if (!*p)
+	start = 0; end = -1;
+	if (parse_range(optarg, PRF_HYPHEN, &start, &end))
+	  bail("bad range `%s'", optarg);
+	if (start < end) {
 	  put_event(EV_WRITE, 0, start);
-	else {
-	  if (!ISDIGIT(*p)) goto bad_range;
-	  end = strtoul(p, &p, 0);
-	  if (errno || *p) goto bad_range;
-	  if (start > end) goto bad_range;
-	  if (start < end) {
-	    put_event(EV_WRITE, 0, start);
-	    put_event(EV_STOP, 0, end);
-	  }
+	  if (end <= SECLIMIT) put_event(EV_STOP, 0, end);
 	}
-	errno = err;
-	break;
-      bad_range:
-	bail("bad range `%s'", optarg);
 	break;
       default: f |= f_bogus; break;
     }
@@ -774,7 +790,7 @@ int main(int argc, char *argv[])
     switch (ev->ev) {
       case EV_WRITE:
 	if (f&f_write)
-	  bail("overlapping ranges: range from %lu still open at %"PRIuSEC"",
+	  bail("overlapping ranges: range from %"PRIuSEC" still open at %"PRIuSEC"",
 	       start, ev->pos);
 	n++; f |= f_write; start = ev->pos;
 	break;