Read Volume Descriptors and identify RR extensions, if any.

.bzrignore

@@ -30,3 +30,4 @@ demo/tree
 demo/ecma119tree
 demo/iso
 demo/catbuffer
+demo/isoread

Makefile.am

@@ -42,6 +42,7 @@ src_libisofs_la_SOURCES = \
 	src/buffer.c \
 	src/rockridge.h \
 	src/rockridge.c \
+	src/rockridge_read.c \
 	src/data_source.c
 libinclude_HEADERS = \
 	src/libisofs.h
@@ -55,7 +56,8 @@ noinst_PROGRAMS = \
 	demo/catbuffer \
 	demo/tree \
 	demo/ecma119tree \
-	demo/iso 
+	demo/iso \
+	demo/isoread 
 
 demo_lsl_CPPFLAGS = -Isrc
 demo_lsl_LDADD = $(src_libisofs_la_OBJECTS) $(THREAD_LIBS)
@@ -81,6 +83,10 @@ demo_iso_CPPFLAGS = -Isrc
 demo_iso_LDADD = $(src_libisofs_la_OBJECTS) $(THREAD_LIBS)
 demo_iso_SOURCES = demo/iso.c
 
+demo_isoread_CPPFLAGS = -Isrc
+demo_isoread_LDADD = $(src_libisofs_la_OBJECTS) $(THREAD_LIBS)
+demo_isoread_SOURCES = demo/iso_read.c
+
 
 ## Build unit test
  

demo/iso_read.c

@@ -0,0 +1,61 @@
+/*
+ * Little program to output the contents of an iso image.
+ * Note that this is not an API example, but a little program for test
+ * purposes.
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "messages.h"
+#include "libisofs.h"
+#include "fs_image.h"
+
+int main(int argc, char **argv)
+{
+    int result;
+    IsoImageFilesystem *fs;
+    IsoDataSource *src;
+    struct iso_read_opts opts = {
+        0, /* block */
+        0, /* norock */
+        0, /* nojoliet */
+        0, /* preferjoliet */
+        0, /* uid; */
+        0, /* gid; */
+        0, /* mode */
+        NULL, /* messenger */
+        "UTF-8" /* input_charset */
+    };
+
+    if (argc != 2) {
+        printf ("You need to specify a valid path\n");
+        return 1;
+    }
+
+    result = libiso_msgs_new(&opts.messenger, 0);
+    if (result <= 0) {
+        printf ("Can't create messenger\n");
+        return 1;
+    }
+    libiso_msgs_set_severities(opts.messenger, LIBISO_MSGS_SEV_NEVER, 
+                               LIBISO_MSGS_SEV_ALL, "", 0);
+    
+    result = iso_data_source_new_from_file(argv[1], &src);
+    if (result < 0) {
+        printf ("Error creating data source\n");
+        return 1;
+    }
+
+    result = iso_image_filesystem_new(src, &opts, &fs);
+    if (result < 0) {
+        printf ("Error creating filesystem\n");
+        return 1;
+    }
+    
+    iso_filesystem_unref((IsoFilesystem*)fs);
+    iso_data_source_unref(src);
+	return 0;
+}

src/error.h

@@ -47,6 +47,7 @@
 
 /* image read errors */
 #define ISO_WRONG_PVD                   -300
+#define ISO_WRONG_RR                    -301
 
 
 #endif /*LIBISO_ERROR_H_*/

src/fs_image.c

@@ -14,6 +14,8 @@
 #include "fs_image.h"
 #include "error.h"
 #include "ecma119.h"
+#include "messages.h"
+#include "rockridge.h"
 
 #include <stdlib.h>
 #include <string.h>
@@ -98,7 +100,10 @@ typedef struct
      * RR version being used in image.
      * 0 no RR extension, 1 RRIP 1.10, 2 RRIP 1.12
      */
-    unsigned int rr_version : 2;
+    enum read_rr_ext rr_version;
+    
+    /** If Joliet extensions are available on image */
+    unsigned int joliet : 1;
 
     /**
      * Number of blocks of the volume, as reported in the PVM.
@@ -181,13 +186,141 @@ void ifs_fs_free(IsoFilesystem *fs)
     free(data);
 }
 
+/**
+ * Read the SUSP system user entries of the "." entry of the root directory, 
+ * indentifying when Rock Ridge extensions are being used.
+ */
+static 
+int read_root_susp_entries(_ImageFsData *data, uint32_t block)
+{
+    int ret;
+    unsigned char buffer[2048];
+    struct ecma119_dir_record *record;
+    struct susp_sys_user_entry *sue;
+    SuspIterator *iter;
+
+    ret = data->src->read_block(data->src, block, buffer);
+    if (ret < 0) {
+        return ret;
+    }
+    
+    /* record will be the "." directory entry for the root record */
+    record = (struct ecma119_dir_record *)buffer;
+    
+    /*
+     * TODO 
+     * SUSP specification claims that for CD-ROM XA the SP entry
+     * is not at position BP 1, but at BP 15. Is that used?
+     * In that case, we need to set info->len_skp to 15!!
+     */
+
+    iter = susp_iter_new(data->src, record, data->len_skp, data->messenger);
+    if (iter == NULL) {
+        return ISO_MEM_ERROR;
+    }
+    
+    /* first entry must be an SP system use entry */
+    ret = susp_iter_next(iter, &sue);
+    if (ret < 0) {
+        /* error */
+        susp_iter_free(iter);
+        return ret;
+    } else if (ret == 0 || !SUSP_SIG(sue, 'S', 'P') ) {
+        iso_msg_debug(data->messenger, "SUSP/RR is not being used.");
+        susp_iter_free(iter);
+        return ISO_SUCCESS;
+    }
+    
+    /* it is a SP system use entry */
+    if (sue->version[0] != 1 || sue->data.SP.be[0] != 0xBE
+        || sue->data.SP.ef[0] != 0xEF) {
+    
+        iso_msg_sorry(data->messenger, LIBISO_SUSP_WRONG, "SUSP SP system use "
+            "entry seems to be wrong. Ignoring Rock Ridge Extensions.");
+        susp_iter_free(iter);
+        return ISO_SUCCESS;
+    }
+    
+    iso_msg_debug(data->messenger, "SUSP/RR is being used.");
+    
+    /*
+     * The LEN_SKP field, defined in IEEE 1281, SUSP. 5.3, specifies the
+     * number of bytes to be skipped within each System Use field.
+     * I think this will be always 0, but given that support this standard
+     * feature is easy...
+     */
+    data->len_skp = sue->data.SP.len_skp[0];
+    
+    /*
+     * Ok, now search for ER entry.
+     * Just notice that the attributes for root dir are read elsewhere.
+     * 
+     * TODO if several ER are present, we need to identify the position of
+     *      what refers to RR, and then look for corresponding ES entry in
+     *      each directory record. I have not implemented this (it's not used,
+     *      no?), but if we finally need it, it can be easily implemented in
+     *      the iterator, transparently for the rest of the code.
+     */
+    while ((ret = susp_iter_next(iter, &sue)) > 0) {
+        
+        /* ignore entries from different version */
+        if (sue->version[0] != 1)
+            continue; 
+        
+        if (SUSP_SIG(sue, 'E', 'R')) {
+               
+            if (data->rr_version) {
+                iso_msg_warn(data->messenger, LIBISO_SUSP_MULTIPLE_ER, 
+                    "More than one ER has found. This is not supported. "
+                    "It will be ignored, but can cause problems. "
+                    "Please notify us about this.");
+            }
+
+            /* 
+             * it seems that Rock Ridge can be identified with any
+             * of the following 
+             */
+            if ( sue->data.ER.len_id[0] == 10 && 
+                 !strncmp((char*)sue->data.ER.ext_id, "RRIP_1991A", 10) ) {
+                
+                iso_msg_debug(data->messenger, 
+                              "Suitable Rock Ridge ER found. Version 1.10.");
+                data->rr_version = RR_EXT_110;
+                
+            } else if ( (sue->data.ER.len_id[0] == 10 && 
+                    !strncmp((char*)sue->data.ER.ext_id, "IEEE_P1282", 10)) 
+                 || (sue->data.ER.len_id[0] == 9 && 
+                    !strncmp((char*)sue->data.ER.ext_id, "IEEE_1282", 9)) ) {
+                 
+                iso_msg_debug(data->messenger, 
+                              "Suitable Rock Ridge ER found. Version 1.12.");
+                data->rr_version = RR_EXT_112;
+                //TODO check also version?
+            } else {
+                iso_msg_warn(data->messenger, LIBISO_SUSP_MULTIPLE_ER, 
+                    "Not Rock Ridge ER found.\n"
+                    "That will be ignored, but can cause problems in "
+                    "image reading. Please notify us about this");
+            }
+        }
+    }
+    
+    susp_iter_free(iter);   
+    
+    if (ret < 0) { 
+        return ret;
+    }
+    
+    return ISO_SUCCESS;
+}
+
 static
 int read_pvm(_ImageFsData *data, uint32_t block)
 {
     int ret;
     struct ecma119_pri_vol_desc *pvm;
     struct ecma119_dir_record *rootdr;
-    unsigned char buffer[BLOCK_SIZE];
+    uint8_t buffer[BLOCK_SIZE];
 
     /* read PVM */
     ret = data->src->read_block(data->src, block, buffer);
@@ -199,10 +332,10 @@ int read_pvm(_ImageFsData *data, uint32_t block)
 
     /* sanity checks */
     if (pvm->vol_desc_type[0] != 1 || pvm->vol_desc_version[0] != 1
-        || strncmp((char*)pvm->std_identifier, "CD001", 5)
+            || strncmp((char*)pvm->std_identifier, "CD001", 5)
-        || pvm->file_structure_version[0] != 1 ) {
+            || pvm->file_structure_version[0] != 1) {
 
-         return ISO_WRONG_PVD;
+        return ISO_WRONG_PVD;
     }
 
     /* ok, it is a valid PVD */
@@ -238,8 +371,10 @@ int iso_image_filesystem_new(IsoDataSource *src, struct iso_read_opts *opts,
                              IsoImageFilesystem **fs)
 {
     int ret;
+    uint32_t block;
     IsoImageFilesystem *ifs;
     _ImageFsData *data;
+    uint8_t buffer[BLOCK_SIZE];
 
     if (src == NULL || opts == NULL || fs == NULL) {
         return ISO_NULL_POINTER;
@@ -265,7 +400,7 @@ int iso_image_filesystem_new(IsoDataSource *src, struct iso_read_opts *opts,
     data->gid = opts->gid;
     data->uid = opts->uid;
     data->mode = opts->mode & ~S_IFMT;
-    data->input_charset = strdup("UTF-8"); //TODO strdup(opts->input_charset);
+    data->input_charset = strdup(opts->input_charset);
     data->messenger = opts->messenger;
 
     ifs->open = ifs_fs_open;
@@ -286,24 +421,100 @@ int iso_image_filesystem_new(IsoDataSource *src, struct iso_read_opts *opts,
     }
 
     /* 3. read next volume descriptors */
-    // TODO
+    block = opts->block + 17;
+    do {
+        ret = src->read_block(src, block, buffer);
+        if (ret < 0) {
+            /* cleanup and exit */
+            goto fs_cleanup;
+        }
+        switch (buffer[0]) {
+        case 0:
+            /* 
+             * This is a boot record 
+             * Here we handle el-torito
+             */
+            //TODO add support for El-Torito
+            iso_msg_hint(data->messenger, LIBISO_UNSUPPORTED_VD,
+                         "El-Torito extensions not supported yet");
+            break;
+        case 2:
+            /* suplementary volume descritor */
+            // TODO support Joliet
+            iso_msg_hint(data->messenger, LIBISO_UNSUPPORTED_VD,
+                         "Joliet extensions not supported yet");
+            break;
+        case 255:
+            /* 
+             * volume set terminator
+             * ignore, as it's checked in loop end condition
+             */
+            break;
+        default:
+            {
+                iso_msg_hint(data->messenger, LIBISO_UNSUPPORTED_VD,
+                             "Ignoring Volume descriptor %x.", buffer[0]);
+            }
+            break;
+        }
+        block++;
+    } while (buffer[0] != 255);
 
     /* 4. check if RR extensions are being used */
-    //TODO
+    ret = read_root_susp_entries(data, data->iso_root_block);
-    //ret = read_root_susp_entries(info, volume->root, data->iso_root_block);
     if (ret < 0) {
         return ret;
     }
     
+    /* user doesn't want to read RR extensions */
+    if (opts->norock) {
+        data->rr = RR_EXT_NO;
+    } else {
+        data->rr = data->rr_version;
+    }
+
     /* select what tree to read */
-    //TODO
+    if (data->rr) {
+        /* RR extensions are available */
+        if (opts->preferjoliet && data->joliet) {
+            /* if user prefers joliet, that is used */
+            iso_msg_debug(data->messenger, "Reading Joliet extensions.");
+            //data->get_name = ucs2str;
+            data->rr = RR_EXT_NO;
+            //data->root_dir_block = joliet root
+            /* root_dir_block already contains root for joliet */
+            //TODO add joliet support
+            goto fs_cleanup;
+        } else {
+            /* RR will be used */
+            iso_msg_debug(data->messenger, "Reading Rock Ridge extensions.");
+            //data->root_dir_block = info.iso_root_block;
+            data->get_name = strcopy;
+        }
+    } else {
+        /* RR extensions are not available */
+        if (opts->preferjoliet && data->joliet) {
+            /* joliet will be used */
+            iso_msg_debug(data->messenger, "Reading Joliet extensions.");
+            //data->get_name = ucs2str;
+            //data->root_dir_block = joliet root
+            /* root_dir_block already contains root for joliet */
+            //TODO add joliet support
+            goto fs_cleanup;
+        } else {
+            /* default to plain iso */
+            iso_msg_debug(data->messenger, "Reading plain ISO-9660 tree.");
+            //data->root_dir_block = info.iso_root_block;
+            data->get_name = strcopy;
+        }
+    }
 
     /* and finally return. Note that we keep the DataSource opened */
 
     *fs = ifs;
     return ISO_SUCCESS;
 
-fs_cleanup: ;
+    fs_cleanup: ;
     ifs_fs_free((IsoFilesystem*)ifs);
     free(ifs);
     return ret;

src/fs_image.h

@@ -42,11 +42,14 @@ struct iso_read_opts
      *  different on a multisession disc.
      */
 
-    unsigned int norock :1; /*< Do not read Rock Ridge extensions */
+    unsigned int norock : 1; /*< Do not read Rock Ridge extensions */
-    //    unsigned int nojoliet:1; /*< Do not read Joliet extensions */
+    unsigned int nojoliet : 1; /*< Do not read Joliet extensions */
-    //    unsigned int preferjoliet:1; 
+
-    /*< When both Joliet and RR extensions are present, the RR
+    /** 
-     *  tree is used. If you prefer using Joliet, set this to 1. */
+     * When both Joliet and RR extensions are present, the RR tree is used. 
+     * If you prefer using Joliet, set this to 1. 
+     */
+    unsigned int preferjoliet : 1; 
     
     uid_t uid; /**< Default uid when no RR */
     gid_t gid; /**< Default uid when no RR */

src/rockridge.h

@@ -27,6 +27,9 @@
 #define LIBISO_ROCKRIDGE_H
 
 #include "ecma119.h"
+#include "messages.h"
+
+#define SUSP_SIG(entry, a, b) ((entry->sig[0] == a) && (entry->sig[1] == b))
 
 /**
  * This contains the information about the System Use Fields (SUSP, 4.1), 
@@ -51,6 +54,89 @@ struct susp_info
     uint8_t **ce_susp_fields;
 };
 
+/* SUSP 5.1 */
+struct susp_CE {
+    uint8_t block[8];
+    uint8_t offset[8];
+    uint8_t len[8];
+};
+
+/* SUSP 5.3 */
+struct susp_SP {
+    uint8_t be[1];
+    uint8_t ef[1];
+    uint8_t len_skp[1];
+};
+
+/* SUSP 5.5 */
+struct susp_ER {
+    uint8_t len_id[1];
+    uint8_t len_des[1];
+    uint8_t len_src[1];
+    uint8_t ext_ver[1];
+    uint8_t ext_id[1]; /*< up to len_id bytes */
+    /* ext_des, ext_src */
+};
+
+/** POSIX file attributes (RRIP, 4.1.1) */
+struct rr_PX {
+    uint8_t mode[8];
+    uint8_t links[8];
+    uint8_t uid[8];
+    uint8_t gid[8];
+    uint8_t serial[8];
+};
+
+/** Time stamps for a file (RRIP, 4.1.6) */
+struct rr_TF {
+    uint8_t flags[1];
+    uint8_t t_stamps[1];
+};
+
+/** Info for character and block device (RRIP, 4.1.2) */
+struct rr_PN {
+    uint8_t high[8];
+    uint8_t low[8];
+};
+
+/** Alternate name (RRIP, 4.1.4) */
+struct rr_NM {
+    uint8_t flags[1];
+    uint8_t name[1];
+};
+
+/** Link for a relocated directory (RRIP, 4.1.5.1) */
+struct rr_CL {
+    uint8_t child_loc[8];
+};
+
+/** Sim link (RRIP, 4.1.3) */
+struct rr_SL {
+    uint8_t flags[1];
+    uint8_t comps[1];
+};
+
+/**
+ * Struct for a SUSP System User Entry (SUSP, 4.1)
+ */
+struct susp_sys_user_entry
+{
+    uint8_t sig[2];
+    uint8_t len_sue[1];
+    uint8_t version[1];
+    union {
+        struct susp_CE CE;
+        struct susp_SP SP;
+        struct susp_ER ER;
+        struct rr_PX PX;
+        struct rr_TF TF;
+        struct rr_PN PN;
+        struct rr_NM NM;
+        struct rr_CL CL;
+        struct rr_SL SL;
+    } data; /* 5 to 4+len_sue */
+};
+
 /**
  * Compute the length needed for write all RR and SUSP entries for a given
  * node.
@@ -105,4 +191,34 @@ void rrip_write_susp_fields(Ecma119Image *t, struct susp_info *info,
  */
 int rrip_write_ce_fields(Ecma119Image *t, struct susp_info *info);
 
+/**
+ * The SUSP iterator is used to iterate over the System User Entries
+ * of a ECMA-168 directory record.
+ * It takes care about Continuation Areas, handles the end of the different
+ * system user entries and skip padding areas. Thus, using an iteration
+ * we are accessing just to the meaning entries.
+ */
+typedef struct susp_iterator SuspIterator;
+
+SuspIterator *
+susp_iter_new(IsoDataSource *src, struct ecma119_dir_record *record, 
+              uint8_t len_skp, IsoMessenger *msgr);
+
+/**
+ * Get the next SUSP System User Entry using given iterator.
+ * 
+ * @param sue
+ *      Pointer to the next susp entry. It refers to an internal buffer and 
+ *      it's not guaranteed to be allocated after calling susp_iter_next() 
+ *      again. Thus, if you need to keep some entry you have to do a copy.
+ * @return
+ *      1 on success, 0 if no more entries, < 0 error
+ */
+int susp_iter_next(SuspIterator *iter, struct susp_sys_user_entry **sue);
+
+/**
+ * Free a given susp iterator.
+ */
+void susp_iter_free(SuspIterator *iter);
+
 #endif /* LIBISO_ROCKRIDGE_H */

src/rockridge_read.c

@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2007 Vreixo Formoso
+ * 
+ * This file is part of the libisofs project; you can redistribute it and/or 
+ * modify it under the terms of the GNU General Public License version 2 as 
+ * published by the Free Software Foundation. See COPYING file for details.
+ */
+
+/*
+ * This file contains functions related to the reading of SUSP and
+ * Rock Ridge extensions on an ECMA-119 image.
+ */
+
+#include "libisofs.h"
+#include "ecma119.h"
+#include "util.h"
+#include "rockridge.h"
+#include "error.h"
+
+#include <sys/stat.h>
+#include <stdlib.h>
+
+struct susp_iterator
+{
+    uint8_t* base;
+    int pos;
+    int size;
+    IsoDataSource *src;
+    IsoMessenger *msgr;
+
+    /* block and offset for next continuation area */
+    uint32_t ce_block;
+    uint32_t ce_off;
+    
+    /** Length of the next continuation area, 0 if no more CA are specified */
+    uint32_t ce_len; 
+
+    uint8_t *buffer; /*< If there are continuation areas */
+};
+
+SuspIterator*
+susp_iter_new(IsoDataSource *src, struct ecma119_dir_record *record,
+              uint8_t len_skp, IsoMessenger *msgr)
+{
+    int pad = (record->len_fi[0] + 1) % 2;
+    struct susp_iterator *iter = malloc(sizeof(struct susp_iterator));
+    if (iter == NULL) {
+        return NULL;
+    }
+
+    iter->base = record->file_id + record->len_fi[0] + pad;
+    iter->pos = len_skp; /* 0 in most cases */
+    iter->size = record->len_dr[0] - record->len_fi[0] - 33 - pad;
+    iter->src = src;
+    iter->msgr = msgr;
+
+    iter->ce_len = 0;
+    iter->buffer = NULL;
+
+    return iter;
+}
+
+int susp_iter_next(SuspIterator *iter, struct susp_sys_user_entry **sue)
+{
+    struct susp_sys_user_entry *entry;
+
+    entry = (struct susp_sys_user_entry*)(iter->base + iter->pos);
+
+    if ( (iter->pos + 4 > iter->size) || (SUSP_SIG(entry, 'S', 'T'))) {
+
+        /* 
+         * End of the System Use Area or Continuation Area.
+         * Note that ST is not needed when the space left is less than 4.
+         * (IEEE 1281, SUSP. section 4) 
+         */
+        if (iter->ce_len) {
+            uint32_t block;
+            int nblocks;
+
+            /* A CE has found, there is another continuation area */
+            nblocks = div_up(iter->ce_off + iter->ce_len, BLOCK_SIZE);
+            iter->buffer = realloc(iter->buffer, nblocks * BLOCK_SIZE);
+
+            /* read all blocks needed to cache the full CE */
+            for (block = 0; block < nblocks; ++block) {
+                int ret;
+                ret = iter->src->read_block(iter->src, iter->ce_block + block,
+                                            iter->buffer + block * BLOCK_SIZE);
+                if (ret < 0) {
+                    return ret;
+                }
+            }
+            iter->base = iter->buffer + iter->ce_off;
+            iter->pos = 0;
+            iter->size = iter->ce_len;
+            iter->ce_len = 0;
+            entry = (struct susp_sys_user_entry*)iter->base;
+        } else {
+            return 0;
+        }
+    }
+
+    if (entry->len_sue[0] == 0) {
+        /* a wrong image with this lead us to a infinity loop */
+        iso_msg_sorry(iter->msgr, LIBISO_RR_ERROR,
+                      "Damaged RR/SUSP information.");
+        return ISO_WRONG_RR;
+    }
+
+    iter->pos += entry->len_sue[0];
+
+    if (SUSP_SIG(entry, 'C', 'E')) {
+        /* Continuation entry */
+        if (iter->ce_len) {
+            iso_msg_sorry(iter->msgr, LIBISO_RR_ERROR, "More than one CE "
+                "System user entry has found in a single System Use field or "
+                "continuation area. This breaks SUSP standard and it's not "
+                "supported. Ignoring last CE. Maybe the image is damaged.");
+        } else {
+            iter->ce_block = iso_read_bb(entry->data.CE.block, 4, NULL);
+            iter->ce_off = iso_read_bb(entry->data.CE.offset, 4, NULL);
+            iter->ce_len = iso_read_bb(entry->data.CE.len, 4, NULL);
+        }
+
+        /* we don't want to return CE entry to the user */
+        return susp_iter_next(iter, sue);
+    } else if (SUSP_SIG(entry, 'P', 'D')) {
+        /* skip padding */
+        return susp_iter_next(iter, sue);
+    }
+
+    *sue = entry;
+    return ISO_SUCCESS;
+}
+
+void susp_iter_free(SuspIterator *iter)
+{
+    free(iter->buffer);
+    free(iter);
+}