diglib: fix for buffer overrrun, https://trac.osgeo.org/grass/ticket/1430

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@47992 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/vector/diglib/portable.c

@@ -186,10 +186,7 @@ int dig__fread_port_O(off_t *buf, size_t cnt, struct gvfile * fp, size_t port_of
 	    memset(buf, 0, cnt * sizeof(off_t));
 	    /* read from buffer in changed order */
 	    c1 = (unsigned char *)buffer;
-	    if (off_t_order == ENDIAN_LITTLE)
-		c2 = (unsigned char *)buf;
-	    else
-		c2 = (unsigned char *)buf + nat_off_t - port_off_t_size;
+	    c2 = (unsigned char *)buf;
 	    for (i = 0; i < cnt; i++) {
 		/* set to FF if the value is negative */
 		if (off_t_order == ENDIAN_LITTLE) {
@@ -200,7 +197,10 @@ int dig__fread_port_O(off_t *buf, size_t cnt, struct gvfile * fp, size_t port_of
 		    if (c1[0] & 0x80)
 			memset(c2, 0xff, sizeof(off_t));
 		}
-		memcpy(c2, c1, port_off_t_size);
+		if (off_t_order == ENDIAN_LITTLE)
+		    memcpy(c2, c1, port_off_t_size);
+		else
+		    memcpy(c2 + nat_off_t - port_off_t_size, c1, port_off_t_size);
 		c1 += port_off_t_size;
 		c2 += sizeof(off_t);
 	    }
@@ -281,10 +281,7 @@ int dig__fread_port_L(long *buf, size_t cnt, struct gvfile * fp)
 	    memset(buf, 0, cnt * sizeof(long));
 	    /* read from buffer in changed order */
 	    c1 = (unsigned char *)buffer;
-	    if (lng_order == ENDIAN_LITTLE)
-		c2 = (unsigned char *)buf;
-	    else
-		c2 = (unsigned char *)buf + nat_lng - PORT_LONG;
+	    c2 = (unsigned char *)buf;
 	    for (i = 0; i < cnt; i++) {
 		/* set to FF if the value is negative */
 		if (lng_order == ENDIAN_LITTLE) {
@@ -295,7 +292,10 @@ int dig__fread_port_L(long *buf, size_t cnt, struct gvfile * fp)
 		    if (c1[0] & 0x80)
 			memset(c2, 0xff, sizeof(long));
 		}
-		memcpy(c2, c1, PORT_LONG);
+		if (lng_order == ENDIAN_LITTLE)
+		    memcpy(c2, c1, PORT_LONG);
+		else
+		    memcpy(c2 + nat_lng - PORT_LONG, c1, PORT_LONG);
 		c1 += PORT_LONG;
 		c2 += sizeof(long);
 	    }
@@ -366,10 +366,7 @@ int dig__fread_port_I(int *buf, size_t cnt, struct gvfile * fp)
 	    memset(buf, 0, cnt * sizeof(int));
 	    /* read from buffer in changed order */
 	    c1 = (unsigned char *)buffer;
-	    if (int_order == ENDIAN_LITTLE)
-		c2 = (unsigned char *)buf;
-	    else
-		c2 = (unsigned char *)buf + nat_int - PORT_INT;
+	    c2 = (unsigned char *)buf;
 	    for (i = 0; i < cnt; i++) {
 		/* set to FF if the value is negative */
 		if (int_order == ENDIAN_LITTLE) {
@@ -380,7 +377,10 @@ int dig__fread_port_I(int *buf, size_t cnt, struct gvfile * fp)
 		    if (c1[0] & 0x80)
 			memset(c2, 0xff, sizeof(int));
 		}
-		memcpy(c2, c1, PORT_INT);
+		if (int_order == ENDIAN_LITTLE)
+		    memcpy(c2, c1, PORT_INT);
+		else
+		    memcpy(c2 + nat_int - PORT_INT, c1, PORT_INT);
 		c1 += PORT_INT;
 		c2 += sizeof(int);
 	    }
@@ -451,10 +451,7 @@ int dig__fread_port_S(short *buf, size_t cnt, struct gvfile * fp)
 	    memset(buf, 0, cnt * sizeof(short));
 	    /* read from buffer in changed order */
 	    c1 = (unsigned char *)buffer;
-	    if (shrt_order == ENDIAN_LITTLE)
-		c2 = (unsigned char *)buf;
-	    else
-		c2 = (unsigned char *)buf + nat_shrt - PORT_SHORT;
+	    c2 = (unsigned char *)buf;
 	    for (i = 0; i < cnt; i++) {
 		/* set to FF if the value is negative */
 		if (shrt_order == ENDIAN_LITTLE) {
@@ -465,7 +462,10 @@ int dig__fread_port_S(short *buf, size_t cnt, struct gvfile * fp)
 		    if (c1[0] & 0x80)
 			memset(c2, 0xff, sizeof(short));
 		}
-		memcpy(c2, c1, PORT_SHORT);
+		if (shrt_order == ENDIAN_LITTLE)
+		    memcpy(c2, c1, PORT_SHORT);
+		else
+		    memcpy(c2 + nat_shrt - PORT_SHORT, c1, PORT_SHORT);
 		c1 += PORT_SHORT;
 		c2 += sizeof(short);
 	    }
@@ -653,15 +653,15 @@ int dig__fwrite_port_O(const off_t *buf,
 	}
 	else if (nat_off_t > port_off_t_size) {
 	    buf_alloc(cnt * port_off_t_size);
-	    if (off_t_order == ENDIAN_LITTLE)
-		c1 = (unsigned char *)buf;
-	    else
-		c1 = (unsigned char *)buf + nat_off_t - port_off_t_size;
+	    c1 = (unsigned char *)buf;
 	    c2 = (unsigned char *)buffer;
 	    for (i = 0; i < cnt; i++) {
-		memcpy(c2, c1, port_off_t_size);
-		c1 += port_off_t_size;
-		c2 += sizeof(off_t);
+		if (off_t_order == ENDIAN_LITTLE)
+		    memcpy(c2, c1, port_off_t_size);
+		else
+		    memcpy(c2, c1 + nat_off_t - port_off_t_size, port_off_t_size);
+		c1 += sizeof(off_t);
+		c2 += port_off_t_size;
 	    }
 	    if (dig_fwrite(buffer, port_off_t_size, cnt, fp) == cnt)
 		return 1;
@@ -719,15 +719,15 @@ int dig__fwrite_port_L(const long *buf,
 	}
 	else {
 	    buf_alloc(cnt * PORT_LONG);
-	    if (lng_order == ENDIAN_LITTLE)
-		c1 = (unsigned char *)buf;
-	    else
-		c1 = (unsigned char *)buf + nat_lng - PORT_LONG;
+	    c1 = (unsigned char *)buf;
 	    c2 = (unsigned char *)buffer;
 	    for (i = 0; i < cnt; i++) {
-		memcpy(c2, c1, PORT_LONG);
-		c1 += PORT_LONG;
-		c2 += sizeof(long);
+		if (lng_order == ENDIAN_LITTLE)
+		    memcpy(c2, c1, PORT_LONG);
+		else
+		    memcpy(c2, c1 + nat_lng - PORT_LONG, PORT_LONG);
+		c1 += sizeof(long);
+		c2 += PORT_LONG;
 	    }
 	    if (dig_fwrite(buffer, PORT_LONG, cnt, fp) == cnt)
 		return 1;
@@ -775,15 +775,15 @@ int dig__fwrite_port_I(const int *buf,
 	}
 	else {
 	    buf_alloc(cnt * PORT_INT);
-	    if (int_order == ENDIAN_LITTLE)
-		c1 = (unsigned char *)buf;
-	    else
-		c1 = (unsigned char *)buf + nat_int - PORT_INT;
+	    c1 = (unsigned char *)buf;
 	    c2 = (unsigned char *)buffer;
 	    for (i = 0; i < cnt; i++) {
-		memcpy(c2, c1, PORT_INT);
-		c1 += PORT_INT;
-		c2 += sizeof(int);
+		if (int_order == ENDIAN_LITTLE)
+		    memcpy(c2, c1, PORT_INT);
+		else
+		    memcpy(c2, c1 + nat_int - PORT_INT, PORT_INT);
+		c1 += sizeof(int);
+		c2 += PORT_INT;
 	    }
 	    if (dig_fwrite(buffer, PORT_INT, cnt, fp) == cnt)
 		return 1;
@@ -831,15 +831,15 @@ int dig__fwrite_port_S(const short *buf,
 	}
 	else {
 	    buf_alloc(cnt * PORT_SHORT);
-	    if (shrt_order == ENDIAN_LITTLE)
-		c1 = (unsigned char *)buf;
-	    else
-		c1 = (unsigned char *)buf + nat_shrt - PORT_SHORT;
+	    c1 = (unsigned char *)buf;
 	    c2 = (unsigned char *)buffer;
 	    for (i = 0; i < cnt; i++) {
-		memcpy(c2, c1, PORT_SHORT);
-		c1 += PORT_SHORT;
-		c2 += sizeof(short);
+		if (shrt_order == ENDIAN_LITTLE)
+		    memcpy(c2, c1, PORT_SHORT);
+		else
+		    memcpy(c2, c1 + nat_shrt - PORT_SHORT, PORT_SHORT);
+		c1 += sizeof(short);
+		c2 += PORT_SHORT;
 	    }
 	    if (dig_fwrite(buffer, PORT_SHORT, cnt, fp) == cnt)
 		return 1;