added info to header in app data area so we can read out skip we used

1 files changed, 62 insertions, 19 deletions

diff --git a/isomd5sum/checkisomd5.c b/isomd5sum/checkisomd5.c
index dfaba9d42..539fcfd89 100644
--- a/isomd5sum/checkisomd5.c
+++ b/isomd5sum/checkisomd5.c
@@ -18,13 +18,14 @@
 #define MAX(x, y)  ((x > y) ? x : y)
 #define MIN(x, y)  ((x < y) ? x : y)
 
-/* number of sectors to ignore at end of iso when computing sum */
-#define SKIPSECTORS 15
-
 /* finds primary volume descriptor and returns info from it */
 /* mediasum must be a preallocated buffer at least 33 bytes long */
-int parsepvd(int isofd, char *mediasum, long long *isosize) {
+int parsepvd(int isofd, char *mediasum, int *skipsectors, long long *isosize) {
     unsigned char buf[2048];
+    unsigned char buf2[512];
+    unsigned char tmpbuf[512];
+    int skipfnd, md5fnd;
+    unsigned int loc;
     long long offset;
     unsigned char *p;
 
@@ -44,15 +45,55 @@ int parsepvd(int isofd, char *mediasum, long long *isosize) {
     }
     
     /* read out md5sum */
-    memcpy(mediasum, buf + APPDATA_OFFSET + 13, 32);
-    mediasum[32] = '\0';
-
-    for (p=mediasum; *p; p++)
-	if (*p != ' ')
-	    break;
+    memcpy(buf2, buf + APPDATA_OFFSET, 512);
+    buf2[511] = '\0';
+
+    md5fnd = 0;
+    skipfnd = 0;
+    loc = 0;
+    while (loc < 512) {
+	if (!strncmp(buf2 + loc, "ISO MD5SUM = ", 13)) {
+
+	    /* make sure we dont walk off end */
+	    if ((loc + 32) > 511)
+		return -1;
+	    
+	    memcpy(mediasum, buf2 + loc + 13, 32);
+	    mediasum[32] = '\0';
+	    md5fnd = 1;
+	    loc += 45;
+	    for (p=buf2+loc; *p != ';' && loc < 512; p++, loc++);
+	} else if (!strncmp(buf2 + loc, "SKIPSECTORS = ", 14)) {
+	    char *errptr;
+
+	    /* make sure we dont walk off end */
+	    if ((loc + 14) > 511)
+		return -1;
+	    
+	    loc = loc + 14;
+	    for (p=tmpbuf; buf2[loc] != ';' && loc < 512; p++, loc++)
+		*p = buf2[loc];
+
+	    *p = '\0';
+
+	    *skipsectors = strtol(tmpbuf, &errptr, 10);
+	    if (errptr && *errptr) {
+ 	        return -1;
+	    } else {
+ 	        skipfnd = 1;
+	    }
+
+	    for (p=buf2+loc; *p != ';' && loc < 512; p++, loc++);
+	} else {
+	    loc += 1;
+	}
 
-    /* if the md5sum was all spaces, we didn't find md5sum */
-    if (!*p)
+	if (skipfnd & md5fnd)
+ 	    break;
+    }
+	    
+	    
+    if (!(skipfnd & md5fnd))
 	return -1;
 
     /* get isosize */
@@ -70,6 +111,7 @@ int checkmd5sum(int isofd, char *mediasum, char *computedsum) {
     int i;
     int appdata_start_offset, appdata_end_offset;
     int nattempt;
+    int skipsectors;
     unsigned int bufsize = 32768;
     unsigned char md5sum[16];
     unsigned int len;
@@ -77,7 +119,7 @@ int checkmd5sum(int isofd, char *mediasum, char *computedsum) {
     long long isosize, offset, pvd_offset, apoff;
     MD5_CTX md5ctx;
 
-    if ((pvd_offset = parsepvd(isofd, mediasum, &isosize)) < 0)
+    if ((pvd_offset = parsepvd(isofd, mediasum, &skipsectors, &isosize)) < 0)
 	return -1;
 
     /*    printf("Mediasum = %s\n",mediasum); */
@@ -91,10 +133,10 @@ int checkmd5sum(int isofd, char *mediasum, char *computedsum) {
     apoff = pvd_offset + APPDATA_OFFSET;
 
     buf = malloc(bufsize * sizeof(unsigned char));
-    printf("Percent complete: %05.1f%%", (100.0*offset)/(isosize-SKIPSECTORS*2048.0));
+    printf("Percent complete: %05.1f%%", (100.0*offset)/(isosize-skipsectors*2048.0));
     fflush(stdout);
-    while (offset < isosize - SKIPSECTORS*2048) {
-	nattempt = MIN(isosize - SKIPSECTORS*2048 - offset, bufsize);
+    while (offset < isosize - skipsectors*2048) {
+	nattempt = MIN(isosize - skipsectors*2048 - offset, bufsize);
 
 	/*	printf("%lld %lld %lld %d\n", offset, isosize, isosize-SKIPSECTORS*2048, nattempt); */
 
@@ -124,11 +166,11 @@ int checkmd5sum(int isofd, char *mediasum, char *computedsum) {
 	MD5_Update(&md5ctx, buf, nread);
 	offset = offset + nread;
 	
-	printf("\b\b\b\b\b\b%05.1f%%", (100.0*offset)/(isosize-SKIPSECTORS*2048.0));
+	printf("\b\b\b\b\b\b%05.1f%%", (100.0*offset)/(isosize-skipsectors*2048.0));
 	fflush(stdout);
     }
 
-    printf("\b\b\b\b\b\b\n\n", (100.0*offset)/(isosize-SKIPSECTORS*2048.0));
+    printf("\b\b\b\b\b\b\n\n", (100.0*offset)/(isosize-skipsectors*2048.0));
     
     sleep(1);
 
@@ -172,8 +214,9 @@ static void readCB(void *co, long long pos) {
 int doMediaCheck(int isofd, char *mediasum, char *computedsum, long long *isosize) {
     int rc;
     int llen;
+    int skipsectors;
 
-    if (parsepvd(isofd, mediasum, isosize) < 0) {
+    if (parsepvd(isofd, mediasum, &skipsectors, isosize) < 0) {
 	fprintf(stderr, "Unable to read the disc checksum from the "
 			 "primary volume descriptor.  This probably "
 			 "means the disc was created without adding the "