New API object iso_interval_reader. Enabling flag bits for older API calls

iso_write_opts_set_prep_img(), iso_write_opts_set_efi_bootp(),
and iso_write_opts_set_partition_img().

libisofs/ecma119.c

@@ -1483,11 +1483,519 @@ static int finish_libjte(Ecma119Image *target)
 }
 
 
+/* >>> need opportunity to just mark a partition in the older sessions
+*/
+
+
+struct iso_interval_zeroizer {
+    int z_type; /* 0= $zero_start"-"$zero_end ,
+                   1= "zero_mbrpt" , 2= "zero_gpt" , 3= "zero_apm"
+                */
+    off_t zero_start;
+    off_t zero_end;
+};
+
+struct iso_interval_reader {
+
+    /* Setup */
+
+    IsoImage *image;
+
+    char *path;
+
+    int flags; /* bit0= imported_iso, else local_fs
+               */
+
+    off_t start_byte;
+    off_t end_byte;
+
+    struct iso_interval_zeroizer *zeroizers;
+    int num_zeroizers;
+
+    char *source_pt; /* This is a parasite pointer of path. Do not free */
+
+    /* State information */
+
+    int initialized;
+    int is_block_aligned;
+    off_t cur_block;
+    int fd;
+    uint8_t read_buf[BLOCK_SIZE];
+    uint8_t *pending_read_pt;
+    int pending_read_bytes;
+    off_t read_count;
+    int eof;
+
+    int src_is_open;
+
+    uint32_t apm_block_size;
+
+};
+
+static
+int iso_ivr_next_comp(char *read_pt, char **next_pt, int flag)
+{
+    *next_pt = NULL;
+    if (read_pt == NULL)
+        return 0;
+    *next_pt = strchr(read_pt, ':');
+    if (*next_pt != NULL)
+        (*next_pt)++;
+    return 1;
+}
+
+/* @param flag bit1= end number requested, forward to iso_scanf_io_size()
+*/
+static
+int iso_ivr_read_number(char *start_pt, char *end_pt, off_t *result, int flag)
+{
+    char txt[20];
+    off_t num;
+
+    if (end_pt - start_pt <= 0 || end_pt - start_pt > 16) {
+        iso_msg_submit(-1, ISO_MALFORMED_READ_INTVL, 0,
+    "Number text too short or too long in interval reader description string");
+        return ISO_MALFORMED_READ_INTVL;
+    }
+    if (end_pt - start_pt > 0)
+        strncpy(txt, start_pt, end_pt - start_pt);
+    txt[end_pt - start_pt] = 0;
+
+    num = iso_scanf_io_size(start_pt, 1 | (flag & 2));
+    if (num < 0.0 || num > 0xffffffffffff) {
+        iso_msg_submit(-1, ISO_MALFORMED_READ_INTVL, 0,
+      "Negative or overly large number in interval reader description string");
+        return ISO_MALFORMED_READ_INTVL;
+    }
+    *result = num;
+    return 1;
+}
+
+static
+int iso_ivr_parse_interval(char *start_pt, char *end_pt, off_t *start_byte,
+                           off_t *end_byte, int flag)
+{
+    int ret;
+    char *m_pt;
+
+    m_pt = strchr(start_pt, '-');
+    if (m_pt == NULL) {
+        iso_msg_submit(-1, ISO_MALFORMED_READ_INTVL, 0,
+              "Malformed byte interval in interval reader description string");
+        return ISO_MALFORMED_READ_INTVL;
+    }
+    ret = iso_ivr_read_number(start_pt, m_pt, start_byte, 0);
+    if (ret < 0)
+        return ret;
+    ret = iso_ivr_read_number(m_pt + 1, end_pt - 1, end_byte, 2);
+    if (ret < 0)
+        return ret;
+    return ISO_SUCCESS;
+}
+
+static
+int iso_ivr_parse_zeroizers(struct iso_interval_reader *ivr,
+                            char *pathpt, char *end_pt, int flag)
+{
+    int ret, num_zs = 1, idx, i;
+    char *rpt, *cpt;
+
+    ivr->num_zeroizers = 0;
+    if (pathpt[0] == 0 || pathpt == end_pt)
+        return ISO_SUCCESS;
+    for(cpt = pathpt - 1; cpt != NULL && cpt < end_pt; num_zs++)
+        cpt = strchr(cpt + 1, ',');
+    LIBISO_ALLOC_MEM(ivr->zeroizers, struct iso_interval_zeroizer, num_zs);
+    for (i = 0; i < num_zs; i++)
+        ivr->zeroizers[i].zero_end = -1;
+    idx = 0;
+    for (rpt = pathpt; rpt != NULL && rpt < end_pt; idx++) {
+        cpt = strchr(rpt, ',');
+        if (cpt == NULL || cpt > end_pt)
+            cpt = end_pt;
+
+        if (cpt == rpt) {
+    continue;
+        } else if (strncmp(rpt, "zero_mbrpt", cpt - rpt) == 0) {
+            ivr->zeroizers[idx].z_type = 1;
+        } else if (strncmp(rpt, "zero_gpt", cpt - rpt) == 0) {
+            ivr->zeroizers[idx].z_type = 2;
+        } else if (strncmp(rpt, "zero_apm", cpt - rpt) == 0) {
+            ivr->zeroizers[idx].z_type = 3;
+        } else {
+            ivr->zeroizers[idx].z_type = 0;
+            ret = iso_ivr_parse_interval(rpt, cpt,
+                                         &(ivr->zeroizers[idx].zero_start),
+                                         &(ivr->zeroizers[idx].zero_end), 0);
+            if (ret < 0)
+                goto ex;
+        }
+        rpt = cpt + 1;
+        ivr->num_zeroizers++;
+    }
+    ret = ISO_SUCCESS;
+ex:;
+    return ret;
+}
+
+static
+int iso_ivr_parse(struct iso_interval_reader *ivr, char *path, int flag)
+{
+    int ret;
+    char *flags_pt, *interval_pt, *zeroize_pt;
+
+    flags_pt = path;
+    iso_ivr_next_comp(flags_pt, &interval_pt, 0);
+    iso_ivr_next_comp(interval_pt, &zeroize_pt, 0);
+    iso_ivr_next_comp(zeroize_pt, &(ivr->source_pt), 0);
+    if (ivr->source_pt == NULL) {
+        iso_msg_submit(-1, ISO_MALFORMED_READ_INTVL, 0,
+                "Not enough components in interval reader description string");
+        return ISO_MALFORMED_READ_INTVL;
+    }
+
+    ivr->flags = 0;
+    if (strncmp(flags_pt, "imported_iso", 12) == 0) {
+        ivr->flags |= 1;
+    } else if (strncmp(flags_pt, "local_fs", 8) == 0) {
+        ;
+    } else {
+        iso_msg_submit(-1, ISO_MALFORMED_READ_INTVL, 0,
+ "Unknown flag name in first component of interval reader description string");
+        return ISO_MALFORMED_READ_INTVL;
+    }
+    ret = iso_ivr_parse_interval(interval_pt, zeroize_pt, &(ivr->start_byte),
+                                 &(ivr->end_byte), 0);
+    if (ret < 0)
+        goto ex;
+    ret = iso_ivr_parse_zeroizers(ivr, zeroize_pt, ivr->source_pt - 1, 0);
+    if (ret < 0)
+        goto ex;
+
+    ret = ISO_SUCCESS;
+ex:;
+    return ret;
+}   
+
+int iso_interval_reader_destroy(struct iso_interval_reader **ivr, int flag)
+{
+    struct iso_interval_reader *o;
+
+    if (*ivr == NULL)
+        return 0;
+    o = *ivr;
+
+    LIBISO_FREE_MEM(o->path);
+    LIBISO_FREE_MEM(o->zeroizers);
+
+    if (o->fd != -1)
+        close(o->fd);
+    if (o->src_is_open)
+        (*o->image->import_src->close)(o->image->import_src);
+
+    LIBISO_FREE_MEM(*ivr);
+    return ISO_SUCCESS;
+}
+
+/* @param flag bit0= tolerate lack of import_src
+*/
+int iso_interval_reader_new(IsoImage *img, char *path,
+                            struct iso_interval_reader **ivr,
+                            off_t *byte_count, int flag)
+{
+    int ret, no_img = 0;
+    struct iso_interval_reader *o = NULL;
+
+    *ivr = NULL;
+    *byte_count = 0;
+    LIBISO_ALLOC_MEM(o, struct iso_interval_reader, 1);
+    o->image = img;
+    o->path = NULL;
+    o->zeroizers = NULL;
+    o->num_zeroizers = 0;
+    o->source_pt = NULL;
+    o->initialized = 0;
+    o->is_block_aligned = 0;
+    o->fd = -1;
+    o->pending_read_pt = NULL;
+    o->pending_read_bytes = 0;
+    o->eof = 0;
+    o->read_count = 0;
+    o->src_is_open = 0;
+
+    o->apm_block_size = 0;
+
+    LIBISO_ALLOC_MEM(o->path, char, strlen(path) + 1);
+    strcpy(o->path, path);
+
+    ret = iso_ivr_parse(o, path, 0);
+    if (ret < 0)
+        goto ex;
+
+    if (o->image == NULL)
+        no_img = 1;
+    else if (o->image->import_src == NULL)
+        no_img = 1;
+    if ((o->flags & 1) && no_img) {
+        iso_msg_submit(-1, ISO_NO_KEPT_DATA_SRC, 0,
+                "Interval reader lacks of data source object of imported ISO");
+        if (!(flag & 1)) {
+            ret = ISO_BAD_PARTITION_FILE;
+            goto ex;
+        }
+        o->eof = 1;
+    }
+    *byte_count = o->end_byte - o->start_byte + 1;
+    *ivr = o;
+    ret = ISO_SUCCESS;
+ex:;
+    if (ret < 0)
+        iso_interval_reader_destroy(&o, 0);
+    return ret;
+}
+
+static
+int iso_ivr_zeroize(struct iso_interval_reader *ivr, uint8_t *buf,
+                             int buf_fill, int flag)
+{
+    int i;
+    off_t low, high, part_start, entry_count, apm_offset = -1, map_entries;
+    uint8_t *apm_buf;
+    struct iso_interval_zeroizer *zr;
+
+    for (i = 0; i < ivr->num_zeroizers; i++) {
+        zr = ivr->zeroizers + i;
+        if (zr->z_type == 1) { /* zero_mbrpt */
+            if (ivr->read_count > 0 || buf_fill < 512)
+    continue;
+            if (buf[510] != 0x55 || buf[511] != 0xaa)
+    continue;
+            memset(buf + 446, 0, 64);
+
+        } else if (zr->z_type == 2) { /* zero_gpt */
+            if (zr->zero_start <= zr->zero_end)
+                goto process_interval;
+
+            if (ivr->read_count > 0 || buf_fill < 512 + 92)
+    continue;
+            if (strncmp((char *) buf + 512, "EFI PART", 8) != 0 ||
+                buf[520] != 0 || buf[521] != 0  || buf[522] != 1 ||
+                buf[523] != 0)
+    continue;
+            /* head_size , curr_lba , entry_size */
+            if (iso_read_lsb(buf + 524, 4) != 92 ||
+                iso_read_lsb(buf + 536, 4) != 1 ||
+                iso_read_lsb(buf + 596, 4) != 128)
+    continue;
+            part_start = iso_read_lsb(buf + 584, 4);
+            entry_count = iso_read_lsb(buf + 592, 4);
+            if (part_start < 2 || part_start + (entry_count + 3) / 4 > 64)
+    continue;
+            zr->zero_start = part_start * 512;
+            zr->zero_end = (part_start + (entry_count + 3) / 4) * 512 - 1;
+            memset(buf + 512, 0, 92);
+
+        } else if (zr->z_type == 3) { /* zero_apm */
+            if (zr->zero_start <= zr->zero_end)
+                goto process_interval;
+
+            if (ivr->read_count == 0) {
+                if (buf_fill < 512)
+    continue;
+                if (buf[0] != 'E' || buf[1] != 'R')
+    continue;
+                ivr->apm_block_size = iso_read_msb(buf + 2, 2);
+                if ((ivr->apm_block_size != 512 &&
+                     ivr->apm_block_size != 1024 &&
+                     ivr->apm_block_size != 2048) ||
+                    ((uint32_t) buf_fill) < ivr->apm_block_size) {
+                    ivr->apm_block_size = 0;
+    continue;
+                }
+                if (ivr->read_count + buf_fill >= 2 * ivr->apm_block_size)
+                    apm_offset = ivr->apm_block_size;
+            } else if (ivr->read_count == 2048 &&
+                       ivr->apm_block_size == 2048 && buf_fill == 2048) {
+                apm_offset = 0;
+            }
+            if (apm_offset < 0)
+    continue;
+
+            /* Check for first APM entry */
+            apm_buf = buf + apm_offset;
+            if(apm_buf[0] != 'P' || apm_buf[1] != 'M')
+    continue;
+            if (iso_read_msb(apm_buf + 8, 4) != 1)
+    continue;
+            map_entries = iso_read_msb(apm_buf + 4, 4);
+            if ((1 + map_entries) * ivr->apm_block_size > 16 * 2048)
+    continue;
+            zr->zero_start = ivr->apm_block_size;
+            zr->zero_end = (1 + map_entries) * ivr->apm_block_size;
+        }
+process_interval:;
+        /* If an interval is defined by now: zeroize its intersection with buf
+         */
+        if (zr->zero_start <= zr->zero_end) {
+            low = ivr->read_count >= zr->zero_start ?
+                  ivr->read_count : zr->zero_start;
+            high = ivr->read_count + buf_fill - 1 <= zr->zero_end ?
+                   ivr->read_count + buf_fill - 1 : zr->zero_end;
+            if (low <= high)
+                memset(buf + low - ivr->read_count, 0, high - low + 1);
+        }
+    }
+
+    return ISO_SUCCESS;
+}
+
+int iso_interval_reader_read(struct iso_interval_reader *ivr, uint8_t *buf,
+                             int *buf_fill, int flag)
+{
+    int ret, read_done, to_copy, initializing = 0;
+    IsoDataSource *src;
+    uint8_t *read_buf;
+    off_t to_read;
+
+    *buf_fill = 0;
+    src = ivr->image->import_src;
+
+    if (ivr->eof) {
+eof:;
+        memset(buf, 0, BLOCK_SIZE);
+        return 0;
+    }
+
+    if (ivr->initialized) {
+        ivr->cur_block++;
+    } else {
+        initializing = 1;
+        ivr->cur_block = ivr->start_byte / BLOCK_SIZE;
+        ivr->is_block_aligned = !(ivr->start_byte % BLOCK_SIZE);
+        if (ivr->flags & 1) {
+            if (src == NULL)
+                goto eof;
+            ret = (*src->open)(src);
+            if (ret < 0) {
+                ivr->eof = 1;
+                return ret;
+            }
+            ivr->src_is_open = 1;
+        } else {
+            ivr->fd = open(ivr->source_pt, O_RDONLY);
+            if (ivr->fd == -1) {
+                iso_msg_submit(-1, ISO_BAD_PARTITION_FILE, 0,
+                         "Cannot open local file for interval reading");
+                ivr->eof = 1;
+                return ISO_BAD_PARTITION_FILE;
+            }
+            if (ivr->cur_block != 0) {
+                if (lseek(ivr->fd, ivr->cur_block * BLOCK_SIZE, SEEK_SET) ==
+                    -1) {
+                    iso_msg_submit(-1, ISO_INTVL_READ_PROBLEM, 0,
+                         "Cannot address interval start in local file");
+                    ivr->eof = 1;
+                    goto eof;
+                }
+            }
+        }
+        ivr->initialized = 1;
+    }
+    if (ivr->is_block_aligned) {
+        read_buf = buf;
+    } else {
+process_pending:;
+        read_buf = ivr->read_buf;
+        /* Copy pending bytes from previous read */
+        if (ivr->pending_read_bytes > 0) {
+            memcpy(buf, ivr->pending_read_pt, ivr->pending_read_bytes);
+            *buf_fill = ivr->pending_read_bytes;
+            ivr->pending_read_bytes = 0;
+        }
+    }
+
+    /* Read next block */
+    read_done = 0;
+    if (ivr->cur_block * BLOCK_SIZE <= ivr->end_byte) {
+        if (ivr->flags & 1) {
+            ret = (*src->read_block)(src, (uint32_t) ivr->cur_block, read_buf);
+            if (ret < 0) {
+                if (iso_error_get_severity(ret) > 0x68000000) /* > FAILURE */
+                    return ret;
+                iso_msg_submit(-1, ISO_INTVL_READ_PROBLEM, 0,
+                     "Premature EOF while interval reading from imported ISO");
+                ivr->eof = 1;
+            }
+            read_done = BLOCK_SIZE;
+        } else {
+            read_done = 0;
+            to_read = ivr->end_byte - ivr->start_byte + 1 - ivr->read_count;
+            if (to_read > BLOCK_SIZE)
+                to_read = BLOCK_SIZE;
+            while (read_done < to_read) {
+                ret = read(ivr->fd, read_buf, to_read - read_done);
+                if (ret == -1) {
+                    iso_msg_submit(-1, ISO_INTVL_READ_PROBLEM, 0,
+                       "Read error while interval reading from local file");
+                    ivr->eof = 1;
+            break;
+                } else if (ret == 0) {
+                    iso_msg_submit(-1, ISO_INTVL_READ_PROBLEM, 0,
+                       "Premature EOF while interval reading from local file");
+                    ivr->eof = 1;
+            break;
+                } else
+                    read_done += ret;
+            }
+        }
+    }
+    if (ivr->is_block_aligned) {
+        *buf_fill = read_done;
+    } else if (initializing) {
+        ivr->pending_read_pt = ivr->read_buf +
+                               (ivr->start_byte - ivr->cur_block * BLOCK_SIZE);
+        ivr->pending_read_bytes = (((off_t) ivr->cur_block) + 1) * BLOCK_SIZE -
+                                  ivr->start_byte;
+        initializing = 0;
+        goto process_pending;
+
+    } else if (read_done > 0) {
+        /* Copy bytes from new read */
+        to_copy = read_done > BLOCK_SIZE - *buf_fill ?
+                  BLOCK_SIZE - *buf_fill : read_done;
+        memcpy(buf + *buf_fill, ivr->read_buf, to_copy);
+        *buf_fill += to_copy;
+        ivr->pending_read_pt = ivr->read_buf + to_copy;
+        ivr->pending_read_bytes = read_done - to_copy;
+    }
+    if (ivr->start_byte + ivr->read_count + *buf_fill - 1 > ivr->end_byte) {
+        *buf_fill = ivr->end_byte - ivr->start_byte + 1 - ivr->read_count;
+        ivr->eof = 1;
+    }
+
+    if (*buf_fill < BLOCK_SIZE)
+        memset(buf + *buf_fill, 0, BLOCK_SIZE - *buf_fill);
+
+    ret = iso_ivr_zeroize(ivr, buf, *buf_fill, 0);
+    if (ret < 0)
+        return ret;
+
+    ivr->read_count += *buf_fill;
+
+    return ISO_SUCCESS;
+}
+
+
 int iso_write_partition_file(Ecma119Image *target, char *path,
                              uint32_t prepad, uint32_t blocks, int flag)
 {
+
+    struct iso_interval_reader *ivr = NULL;
+    int buf_fill;
+    off_t byte_count;
     FILE *fp = NULL;
-    uint32_t i;
+
+    uint32_t i, intvl_blocks;
     uint8_t *buf = NULL;
     int ret;
 
@@ -1498,10 +2006,21 @@ int iso_write_partition_file(Ecma119Image *target, char *path,
             goto ex;
     }
 
-/* >>> need opportunity to read from input ISO image
+    if (flag & 1) {
-       resp. to just mark a partition in the older sessions
+        ret = iso_interval_reader_new(target->image, path,
-*/;
+                                      &ivr, &byte_count, 0);
-
+        if (ret < 0)
+            goto ex;
+        intvl_blocks = (byte_count + BLOCK_SIZE - 1) / BLOCK_SIZE;
+        for (i = 0; i < blocks; i++) {
+            ret = iso_interval_reader_read(ivr, buf, &buf_fill, 0);
+            if (ret < 0)
+                goto ex;
+            ret = iso_write(target, buf, BLOCK_SIZE);
+            if (ret < 0)
+                goto ex;
+        }
+    } else {
         fp = fopen(path, "rb");
         if (fp == NULL)
             {ret = ISO_BAD_PARTITION_FILE; goto ex;}
@@ -1523,8 +2042,10 @@ int iso_write_partition_file(Ecma119Image *target, char *path,
         }
         if (fp != NULL) 
             fclose(fp);
+    }
     ret = ISO_SUCCESS;
 ex:;
+    iso_interval_reader_destroy(&ivr, 0);
     LIBISO_FREE_MEM(buf);
     return ret;
 }
@@ -1594,7 +2115,8 @@ void *write_function(void *arg)
         res = iso_write_partition_file(target,
                                      target->opts->appended_partitions[i],
                                      target->appended_part_prepad[i],
-                                       target->appended_part_size[i], 0);
+                                     target->appended_part_size[i],
+                                     target->opts->appended_part_flags[i] & 1);
         if (res < 0)
             goto write_error;
     }
@@ -2825,9 +3347,14 @@ int iso_write_opts_new(IsoWriteOpts **opts, int profile)
 
     wopts->tail_blocks = 0;
     wopts->prep_partition = NULL;
+    wopts->prep_part_flag = 0;
     wopts->efi_boot_partition = NULL;
-    for (i = 0; i < ISO_MAX_PARTITIONS; i++)
+    wopts->efi_boot_part_flag = 0;
+    for (i = 0; i < ISO_MAX_PARTITIONS; i++) {
         wopts->appended_partitions[i] = NULL;
+        wopts->appended_part_types[i] = 0;
+        wopts->appended_part_flags[i] = 0;
+    }
     wopts->appended_as_gpt = 0;
     wopts->ascii_disc_label[0] = 0;
     wopts->will_cancel = 0;
@@ -3510,6 +4037,7 @@ int iso_write_opts_set_prep_img(IsoWriteOpts *opts, char *image_path, int flag)
     opts->prep_partition = strdup(image_path);
     if (opts->prep_partition == NULL)
         return ISO_OUT_OF_MEM;
+    opts->prep_part_flag = (flag & 1);
     return ISO_SUCCESS;
 }
 
@@ -3523,6 +4051,7 @@ int iso_write_opts_set_efi_bootp(IsoWriteOpts *opts, char *image_path,
     opts->efi_boot_partition = strdup(image_path);
     if (opts->efi_boot_partition == NULL)
         return ISO_OUT_OF_MEM;
+    opts->efi_boot_part_flag = (flag & 1);
     return ISO_SUCCESS;
 }
 
@@ -3539,6 +4068,7 @@ int iso_write_opts_set_partition_img(IsoWriteOpts *opts, int partition_number,
     if (opts->appended_partitions[partition_number - 1] == NULL)
         return ISO_OUT_OF_MEM;
     opts->appended_part_types[partition_number - 1] = partition_type;
+    opts->appended_part_flags[partition_number - 1] = (flag & 1);
     return ISO_SUCCESS;
 }
 

libisofs/ecma119.h

@@ -468,17 +468,20 @@ struct iso_write_opts {
        to HFS+/FAT and IsoFileSrc areas and marked by an MBR partition entry.
     */
     char *prep_partition;
+    int prep_part_flag;
 
     /* Eventual disk file path of an EFI system partition image which shall
        be prepended to HFS+/FAT and IsoFileSrc areas and marked by a GPT entry.
     */
     char *efi_boot_partition;
+    int efi_boot_part_flag;
 
     /* Eventual disk file paths of prepared images which shall be appended
        after the ISO image and described by partiton table entries in a MBR
     */
     char *appended_partitions[ISO_MAX_PARTITIONS]; 
     uint8_t appended_part_types[ISO_MAX_PARTITIONS];
+    int appended_part_flags[ISO_MAX_PARTITIONS];
 
     /* If 1: With appended partitions: create protective MBR and mark by GPT
      */

libisofs/fs_image.c

@@ -124,6 +124,12 @@ struct iso_read_opts
      * submission by iso_write_opts_set_system_area(data, 0).
      */
     int load_system_area;
+
+    /**
+     * Keep data source of imported ISO filesystem in IsoImage.import_src
+     */
+    int keep_import_src;
+
 };
 
 /**
@@ -5620,6 +5626,10 @@ int iso_image_import(IsoImage *image, IsoDataSource *src,
     data = fs->data;
 
 
+    if (opts->keep_import_src) {
+        iso_data_source_ref(src);
+        image->import_src = src;
+    }
     if (opts->load_system_area) {
         if (image->system_area_data != NULL)
             free(image->system_area_data);
@@ -6029,6 +6039,7 @@ int iso_read_opts_new(IsoReadOpts **opts, int profile)
     ropts->noaaip = 1;
     ropts->nomd5 = 1;
     ropts->load_system_area = 0;
+    ropts->keep_import_src = 0;
 
     *opts = ropts;
     return ISO_SUCCESS;
@@ -6173,6 +6184,15 @@ int iso_read_opts_load_system_area(IsoReadOpts *opts, int mode)
     return ISO_SUCCESS;
 }
 
+int iso_read_opts_keep_import_src(IsoReadOpts *opts, int mode)
+{
+    if (opts == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    opts->keep_import_src = mode & 1;
+    return ISO_SUCCESS;
+}
+
 /**
  * Destroy an IsoReadImageFeatures object obtained with iso_image_import.
  */

libisofs/image.c

@@ -185,6 +185,7 @@ int iso_image_new(const char *name, IsoImage **image)
     img->hppa_kernel_64 = NULL;
     img->hppa_ramdisk = NULL;
     img->alpha_boot_image = NULL;
+    img->import_src = NULL;
     img->builder_ignore_acl = 1;
     img->builder_ignore_ea = 1;
     img->inode_counter = 0;
@@ -245,6 +246,8 @@ void iso_image_unref(IsoImage *image)
         iso_image_set_hppa_palo(image, NULL, NULL, NULL, NULL, NULL, 1);
         if (image->alpha_boot_image != NULL)
             free(image->alpha_boot_image);
+        if (image->import_src != NULL)
+            iso_data_source_unref(image->import_src);
         free(image->volset_id);
         free(image->volume_id);
         free(image->publisher_id);

libisofs/image.h

@@ -64,6 +64,8 @@ struct Iso_Image
     /* Eventually loaded system area data, or NULL */
     char *system_area_data;
     /* Prescribed/detected options, see iso_write_opts_set_system_area() */
+    /* >>> Needs to be coordinated with .imported_sa_info->system_area_options
+    */
     int system_area_options;
 
    /*
@@ -100,6 +102,11 @@ struct Iso_Image
     IsoFilesystem *fs;
 
     /**
+     * Block storage of imported ISO if demanded by IsoReadOpts.
+     */
+    IsoDataSource *import_src;
+
+    /*
      * Default builder to use when adding files to the image tree.
      */
     IsoNodeBuilder *builder;

libisofs/libisofs.h

@@ -2409,6 +2409,117 @@ int iso_write_opts_detach_jte(IsoWriteOpts *opts, void **libjte_handle);
  */
 int iso_write_opts_set_tail_blocks(IsoWriteOpts *opts, uint32_t num_blocks);
 
+
+/**
+ * The libisofs interval reader is used internally and offered by libisofs API:
+ * @since 1.4.0
+ * The functions iso_write_opts_set_prep_img(), iso_write_opts_set_efi_bootp(),
+ * and iso_write_opts_set_partition_img() accept with their flag bit0 an
+ * interval reader description string instead of a disk path.
+ * The API calls are iso_interval_reader_new(), iso_interval_reader_read(),
+ * and iso_interval_reader_destroy().
+ * The data may be cut out and optionally partly zeroized.
+ *
+ * An interval reader description string has the form:
+ *   $flags:$interval:$zeroizers:$source
+ * The component $flags modifies the further interpretation:
+ *  "local_fs" ....... demands to read from a file depicted by the path in
+ *                     $source.
+ *  "imported_iso" ... demands to read from the IsoDataSource object that was
+ *                     used with iso_image_import() when
+ *                     iso_read_opts_keep_import_src() was enabled.
+ *                     The text in $source is ignored.
+ *                     The application has to ensure that reading from the
+ *                     import source does not disturb production of the new
+ *                     ISO session. Especially this would be the case if the
+ *                     import source is the same libburn drive with a
+ *                     sequential optical medium to which the new session shall
+ *                     get burned.
+ * The component $interval consists of two byte address numbers separated
+ * by a "-" character. E.g. "0-429" means to read bytes 0 to 429.
+ * The component $zeroizers consists of zero or more comma separated strings.
+ * They define which part of the read data to zeroize. Byte number 0 means
+ * the byte read from the $interval start address.
+ * Each string may be either
+ *  "zero_mbrpt" ..... demands to zeroize bytes 446 to 509 of the read data if
+ *                     bytes 510 and 511 bear the MBR signature 0x55 0xaa.
+ *  "zero_gpt" ....... demands to check for a GPT header in bytes 512 to 1023,
+ *                     to zeroize it and its partition table blocks.
+ *  "zero_apm" ....... demands to check for an APM block 0 and to zeroize
+ *                     its partition table blocks. But not the block 0 itself,
+ *                     because it could be actually MBR x86 machine code.
+ *  $zero_start"-"$zero_end ... demands to zeroize the read-in bytes beginning
+ *                     with number $zero_start and ending after $zero_end. 
+ * The component $source is the file path with "local_fs", and ignored with
+ * "imported_iso".
+ * Byte numbers may be scaled by a suffix out of {k,m,g,t,s,d} meaning
+ * multiplication by {1024, 1024k, 1024m, 1024g, 2048, 512}. A scaled value
+ * as end number depicts the last byte of the scaled range.
+ * E.g. "0d-0d" is "0-511".
+ * Examples:
+ *    "local_fs:0-32767:zero_mbrpt,zero_gpt,440-443:/tmp/template.iso"
+ *    "imported_iso:45056d-47103d::"
+ */
+struct iso_interval_reader;
+
+/**
+ * Create an interval reader object.
+ *
+ * @param img
+ *        The IsoImage object which can provide the "imported_iso" data source.
+ * @param path
+ *        The interval reader description string. See above.
+ * @param ivr
+ *        Returns in case of success a pointer to the created object.
+ *        Dispose it by iso_interval_reader_destroy() when no longer needed.
+ * @param byte_count
+ *        Returns in case of success the number of bytes in the interval.
+ * @param flag
+ *        bit0= tolerate (src == NULL) with "imported_iso".
+ *              (Will immediately cause eof of interval input.)
+ * @return
+ *        ISO_SUCCESS or error (which is < 0)
+ *
+ * @since 1.4.0
+ */
+int iso_interval_reader_new(IsoImage *img, char *path,
+                            struct iso_interval_reader **ivr,
+                            off_t *byte_count, int flag);
+
+/**
+ * Dispose an interval reader object.
+ *
+ * @param ivr
+ *        The reader object to be disposed. *ivr will be set to NULL.
+ * @return
+ *        ISO_SUCCESS or error (which is < 0)
+ * 
+ * @since 1.4.0
+ */ 
+int iso_interval_reader_destroy(struct iso_interval_reader **ivr, int flag);
+
+/**
+ * Read the next block of 2048 bytes from an interval reader object.
+ * If end-of-input happens, the interval will get filled up with 0 bytes.
+ *
+ * @param ivr
+ *        The object to read from.
+ * @param buf
+ *        Pointer to memory for filling in at least 2048 bytes.
+ * @param buf_fill
+ *        Will in case of success return the number of valid bytes.
+ *        If this is smaller than 2048, then end-of-interval has occured.
+ * @param flag
+ *        Unused yet. Submit 0.
+ * @return
+ *        ISO_SUCCESS if data were read, 0 if not, < 0 if error
+ *
+ * @since 1.4.0
+ */
+int iso_interval_reader_read(struct iso_interval_reader *ivr, uint8_t *buf,
+                             int *buf_fill, int flag);
+
+
 /**
  * Copy a data file from the local filesystem into the emerging ISO image.
  * Mark it by an MBR partition entry as PreP partition and also cause
@@ -2427,10 +2538,14 @@ int iso_write_opts_set_tail_blocks(IsoWriteOpts *opts, uint32_t num_blocks);
  * @param opts
  *        The option set to be manipulated.
  * @param image_path
- *        File address in the local file system.
+ *        File address in the local file system or instructions for interval
+ *        reader. See flag bit0.
  *        NULL revokes production of the PreP partition.
  * @param flag
- *        Reserved for future usage, set to 0.
+ *        bit0= The path contains instructions for the interval reader.
+ *              See above.
+ *              @since 1.4.0
+ *        All other bits are reserved for future usage. Set them to 0.
  * @return
  *        ISO_SUCCESS or error
  *
@@ -2457,10 +2572,14 @@ int iso_write_opts_set_prep_img(IsoWriteOpts *opts, char *image_path,
  * @param opts
  *        The option set to be manipulated.
  * @param image_path
- *        File address in the local file system.
+ *        File address in the local file system or instructions for interval
+ *        reader. See flag bit0.
  *        NULL revokes production of the EFI boot partition.
  * @param flag
- *        Reserved for future usage, set to 0.
+ *        bit0= The path contains instructions for the interval reader
+ *              See above.
+ *              @since 1.4.0
+ *        All other bits are reserved for future usage. Set them to 0.
  * @return
  *        ISO_SUCCESS or error
  *
@@ -2488,7 +2607,8 @@ int iso_write_opts_set_efi_bootp(IsoWriteOpts *opts, char *image_path,
  *                        unclaimable space before partition 1.
  *        Range with SUN Disk Label: 2 to 8.
  * @param image_path
- *        File address in the local file system.
+ *        File address in the local file system or instructions for interval
+ *        reader. See flag bit0.
  *        With SUN Disk Label: an empty name causes the partition to become
  *        a copy of the next lower partition.
  * @param image_type
@@ -2496,7 +2616,9 @@ int iso_write_opts_set_efi_bootp(IsoWriteOpts *opts, char *image_path,
  *        Linux Native Partition = 0x83. See fdisk command L.
  *        This parameter is ignored with SUN Disk Label.
  * @param flag
- *        bit0= The path may contain instructions for the interval reader
+ *        bit0= The path contains instructions for the interval reader
+ *              See above.
+ *              @since 1.4.0
  *        All other bits are reserved for future usage. Set them to 0.
  * @return
  *        ISO_SUCCESS or error
@@ -2816,6 +2938,24 @@ int iso_read_opts_auto_input_charset(IsoReadOpts *opts, int mode);
  */
 int iso_read_opts_load_system_area(IsoReadOpts *opts, int mode);
 
+/**
+ * Control whether to keep a reference to the IsoDataSource object which
+ * allows access to the blocks of the imported ISO 9660 filesystem.
+ * This is needed if the interval reader shall read from "imported_iso".
+ *
+ * @param opts
+ *       The option set to be manipulated
+ * @param mode
+ *       Bitfield for control purposes:
+ *       bit0= Keep a reference to the IsoDataSource until the IsoImage object
+ *             gets disposed by its final iso_image_unref().
+ *       Submit any other bits with value 0.
+ *
+ * @since 1.4.0
+ *
+ */
+int iso_read_opts_keep_import_src(IsoReadOpts *opts, int mode);
+
 /**
  * Import a previous session or image, for growing or modify.
  *
@@ -8161,7 +8301,17 @@ int iso_conv_name_chars(IsoWriteOpts *opts, char *name, size_t name_len,
 #define ISO_INQ_SYSAREA_PROP        0xE830FE6C
 
 /** DEC Alpha Boot Loader file is not a data file   (FAILURE, HIGH, -405) */
-#define ISO_ALPHA_BOOT_NOTREG       0xE830FE6A
+#define ISO_ALPHA_BOOT_NOTREG       0xE830FE6B
+
+/** No data source of imported ISO image available  (WARNING, HIGH, -406) */
+#define ISO_NO_KEPT_DATA_SRC        0xD030FE6A
+
+/** Malformed description string for interval reader (FAILURE, HIGH, -407) */
+#define ISO_MALFORMED_READ_INTVL    0xE830FE69
+
+/** Unreadable file, premature EOF, or failure to seek for interval reader
+                                                       (WARNING, HIGH, -408) */
+#define ISO_INTVL_READ_PROBLEM      0xD030FE68
 
 
 /* Internal developer note: 

libisofs/libisofs.ver

@@ -141,6 +141,9 @@ iso_image_unref;
 iso_image_update_sizes;
 iso_init;
 iso_init_with_flag;
+iso_interval_reader_destroy;
+iso_interval_reader_new;
+iso_interval_reader_read;
 iso_lib_is_compatible;
 iso_lib_version;
 iso_local_attr_support;
@@ -216,6 +219,7 @@ iso_read_image_features_has_joliet;
 iso_read_image_features_has_rockridge;
 iso_read_opts_auto_input_charset;
 iso_read_opts_free;
+iso_read_opts_keep_import_src;
 iso_read_opts_load_system_area;
 iso_read_opts_new;
 iso_read_opts_set_default_gid;

libisofs/messages.c

@@ -521,6 +521,12 @@ const char *iso_error_to_msg(int errcode)
         return "Unrecognized inquiry for system area property";
     case ISO_ALPHA_BOOT_NOTREG:
         return "DEC Alpha Boot Loader file is not a data file";
+    case ISO_NO_KEPT_DATA_SRC:
+        return "No data source of imported ISO image available";
+    case ISO_MALFORMED_READ_INTVL:
+        return "Malformed description string for interval reader";
+    case ISO_INTVL_READ_PROBLEM:
+        return "Unreadable file, premature EOF, or failure to seek for interval reader";
     default:
         return "Unknown error";
     }

libisofs/system_area.c

@@ -107,12 +107,26 @@ void iso_compute_cyl_head_sec(uint64_t img_blocks, int hpc, int sph,
     }
 }
 
-static uint32_t compute_partition_size(char *disk_path, uint32_t *size,
+/* @param flag bit0= The path contains instructions for the interval reader
-                                       int flag)
+*/
+static int compute_partition_size(Ecma119Image *t, char *disk_path,
+                                  uint32_t *size, int flag)
 {
     int ret;
     off_t num;
     struct stat stbuf;
+    struct iso_interval_reader *ivr;
+    off_t byte_count;
+
+    if (flag & 1) {
+        ret = iso_interval_reader_new(t->image, disk_path,
+                                      &ivr, &byte_count, 0);
+        if (ret < 0)
+            return ret;
+        *size = (byte_count + BLOCK_SIZE - 1) / BLOCK_SIZE;
+        iso_interval_reader_destroy(&ivr, 0);
+        return ISO_SUCCESS;
+    }
 
     *size = 0;
     ret = stat(disk_path, &stbuf);
@@ -150,8 +164,8 @@ int iso_compute_append_partitions(Ecma119Image *t, int flag)
     continue;
         if (t->opts->appended_partitions[i][0] == 0)
     continue;
-        ret = compute_partition_size(t->opts->appended_partitions[i], &size,
+        ret = compute_partition_size(t, t->opts->appended_partitions[i], &size,
-                                     0);
+                                     t->opts->appended_part_flags[i]);
         if (ret < 0)
             return ret;
         add_pos = 0;
@@ -255,7 +269,7 @@ static int write_mbr_partition_entry(int partition_number, int partition_type,
 */
 static
 int make_grub_msdos_label(uint32_t img_blocks, int sph, int hpc,
-                          uint8_t *buf, int flag)
+                          uint8_t part_type, uint8_t *buf, int flag)
 {
     uint8_t *wpt;
     uint32_t end_lba, end_sec, end_head, end_cyl;
@@ -286,7 +300,7 @@ int make_grub_msdos_label(uint32_t img_blocks, int sph, int hpc,
     *(wpt++) = 0;
 
     /* 0xcd (partition type) */
-    *(wpt++) = 0xcd;
+    *(wpt++) = part_type;
 
     /* [3 bytes of C/H/S end], */
     *(wpt++) = end_head;
@@ -1660,7 +1674,7 @@ int iso_write_system_area(Ecma119Image *t, uint8_t *buf)
     int first_partition = 1, last_partition = 4, apm_flag, part_type = 0;
     int gpt_count = 0, gpt_idx[128], apm_count = 0, no_boot_mbr = 0;
     int offset_flag = 0;
-    uint32_t img_blocks, gpt_blocks, mbrp1_blocks;
+    uint32_t img_blocks, gpt_blocks, mbrp1_blocks, pml_blocks;
     uint64_t blk;
     uint8_t *wpt;
 
@@ -1767,8 +1781,16 @@ int iso_write_system_area(Ecma119Image *t, uint8_t *buf)
         if (t->mbr_req_count == 0){
             /* Write GRUB protective msdos label, i.e. a simple partition
                table */
-            ret = make_grub_msdos_label(img_blocks, t->partition_secs_per_head,
+            if (t->gpt_req_count > 0) {
-                                      t->partition_heads_per_cyl, buf, 0);
+                part_type = 0xee;
+                pml_blocks = gpt_blocks;
+            } else {
+                part_type = 0xcd;
+                pml_blocks = img_blocks;
+            }
+            ret = make_grub_msdos_label(pml_blocks, t->partition_secs_per_head,
+                                        t->partition_heads_per_cyl,
+                                        (uint8_t) part_type, buf, 0);
             if (ret != ISO_SUCCESS) /* error should never happen */
                return ISO_ASSERT_FAILURE;
         }
@@ -1826,7 +1848,8 @@ int iso_write_system_area(Ecma119Image *t, uint8_t *buf)
                sa_type == 0 && t->mbr_req_count == 0) {
         /* Write a simple partition table. */
         ret = make_grub_msdos_label(img_blocks, t->partition_secs_per_head,
-                                    t->partition_heads_per_cyl, buf, 2);
+                                    t->partition_heads_per_cyl,
+                                    (uint8_t) 0xcd, buf, 2);
         if (ret != ISO_SUCCESS) /* error should never happen */
             return ISO_ASSERT_FAILURE;
         if (t->opts->appended_as_gpt && t->have_appended_partitions) {
@@ -1961,7 +1984,8 @@ int iso_align_isohybrid(Ecma119Image *t, int flag)
 
     img_blocks = t->curblock + t->opts->tail_blocks + t->gpt_backup_size;
     imgsize = ((off_t) img_blocks) * (off_t) 2048;
-    if (((t->system_area_options & 3) || always_align)
+    if ((!(t->opts->appended_as_gpt && t->have_appended_partitions))
+        && ((t->system_area_options & 3) || always_align)
         && (off_t) (t->partition_heads_per_cyl * t->partition_secs_per_head
                     * 1024) * (off_t) 512 < imgsize) {
         /* Choose small values which can represent the image size */
@@ -2585,7 +2609,7 @@ static int partprepend_writer_compute_data_blocks(IsoImageWriter *writer)
                 t->efi_boot_part_size += (src->sections[i].size + 2047) / 2048;
             }
         } else {
-            ret = compute_partition_size(t->opts->efi_boot_partition,
+            ret = compute_partition_size(t, t->opts->efi_boot_partition,
                                          &(t->efi_boot_part_size), 0);
             if (ret < 0)
                 return ret;
@@ -2615,7 +2639,7 @@ static int partprepend_writer_compute_data_blocks(IsoImageWriter *writer)
     }
 
     if (t->opts->prep_partition != NULL) {
-        ret = compute_partition_size(t->opts->prep_partition,
+        ret = compute_partition_size(t, t->opts->prep_partition,
                                      &(t->prep_part_size), 0);
         if (ret < 0)
             return ret;
@@ -2672,14 +2696,16 @@ static int partprepend_writer_write_data(IsoImageWriter *writer)
                                          NULL, NULL, 0);
         } else {
             ret = iso_write_partition_file(t, t->opts->efi_boot_partition,
-                                       (uint32_t) 0, t->efi_boot_part_size, 0);
+                                       (uint32_t) 0, t->efi_boot_part_size,
+                                       t->opts->efi_boot_part_flag & 1);
         }
         if (ret < 0)
             return ret;
     }
     if (t->opts->prep_partition != NULL && t->prep_part_size) {
         ret = iso_write_partition_file(t, t->opts->prep_partition,
-                                       (uint32_t) 0, t->prep_part_size, 0);
+                                       (uint32_t) 0, t->prep_part_size,
+                                       t->opts->prep_part_flag & 1);
         if (ret < 0)
             return ret;
     }
@@ -2762,7 +2788,8 @@ static int partappend_writer_write_data(IsoImageWriter *writer)
         res = iso_write_partition_file(target,
                                        target->opts->appended_partitions[i],
                                        target->appended_part_prepad[i],
-                                       target->appended_part_size[i], 0);
+                                       target->appended_part_size[i],
+                                       target->appended_part_flags[i] & 1);
         if (res < 0)
             return res;
         target->curblock += target->appended_part_size[i];

libisofs/util.c

@@ -2305,3 +2305,41 @@ int iso_clone_mgtd_mem(char *in, char **out, size_t size)
     return iso_clone_mem(in, out, size);
 }
 
+
+/** Convert a text into a number of type double and multiply it by unit code
+    [kmgt] (2^10 to 2^40) or [s] (2048) or [d] (512).
+    (Also accepts capital letters.)
+    @param text Input like "42", "223062s", "3m" or "-1g"
+    @param flag Bitfield for control purposes:
+                bit0= return -1 rathern than 0 on failure
+                bit1= if scaled then compute the last byte of the last unit
+    @return The derived value
+*/
+off_t iso_scanf_io_size(char *text, int flag)
+{
+    int c;
+    off_t ret = 0, fac = 1;
+    char *rpt;
+
+    for (rpt = text; *rpt >= '0' && *rpt <= '9'; rpt++)
+        ret = ret * 10 + (*rpt - '0');
+    if (rpt == text)
+        return (off_t) (flag & 1 ? -1 : 0);
+    c = *rpt;
+    if (c=='k' || c=='K')
+        fac = 1024;
+    else if (c=='m' || c=='M')
+        fac = 1024 * 1024;
+    else if (c=='g' || c=='G')
+        fac = 1024 * 1024 * 1024;
+    else if (c=='t' || c=='T')
+        fac = ((off_t) 1024) * 1024 * 1024 * 1024;
+    else if (c=='s' || c=='S')
+        fac = 2048;
+    else if (c=='d' || c=='D')
+        fac = 512;
+    ret *= fac;
+    if (flag & 2)
+        ret += fac - 1;
+    return ret;
+}

libisofs/util.h

@@ -21,6 +21,10 @@
 
 #include <time.h>
 
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+
 #ifndef MAX
 #   define MAX(a, b) (((a) > (b)) ? (a) : (b))
 #endif
@@ -627,6 +631,16 @@ int iso_clone_mem(char *in, char **out, size_t size);
 */
 int iso_clone_mgtd_mem(char *in, char **out, size_t size);
 
+/** Convert a text into a number of type double and multiply it by unit code
+    [kmgt] (2^10 to 2^40) or [s] (2048) or [d] (512).
+    (Also accepts capital letters.)
+    @param text Input like "42", "223062s", "3m" or "-1g"
+    @param flag Bitfield for control purposes:
+                bit0= return -1 rathern than 0 on failure
+                bit1= if scaled then compute the last byte of the last unit
+    @return The derived value
+*/
+off_t iso_scanf_io_size(char *text, int flag);
 
 /* ------------------------------------------------------------------------- */