Reorganise archive extraction code

git-svn-id: svn://busybox.net/trunk/busybox@2823 69ca8d6d-28ef-0310-b511-8ec308f3f277

3 files changed, 94 insertions, 68 deletions

diff --git a/libbb/deb_extract.c b/libbb/deb_extract.c
index 36cebfa51..f64193970 100644
--- a/libbb/deb_extract.c
+++ b/libbb/deb_extract.c
@@ -27,71 +27,97 @@
 #include <unistd.h>
 #include <stdlib.h>
 #include <string.h>
-#include <signal.h>
 #include "libbb.h"
 
+int seek_sub_file(FILE *in_file, file_headers_t *headers, const char *tar_gz_file)
+{
+        /* find the headers for the specified .tar.gz file */
+        while (headers != NULL) {
+                if (strcmp(headers->name, tar_gz_file) == 0) {
+                        fseek(in_file, headers->offset, SEEK_SET);
+                        return(EXIT_SUCCESS);
+                }
+                headers = headers->next;
+        }
+
+        return(EXIT_FAILURE);
+}
+
 /*
  * The contents of argument depend on the value of function.
  * It is either a dir name or a control file or field name(see dpkg_deb.c)
  */
-extern char *deb_extract(const char *package_filename, const int function, const char *argument, const char *argument2)
+char *deb_extract(const char *package_filename, FILE *out_stream, const int extract_function,
+        const char *prefix, const char *filename)
 {
+        FILE *deb_stream, *uncompressed_stream;
+        file_headers_t *ar_headers = NULL;
+        file_headers_t *tar_headers = NULL;
+        file_headers_t *list_ptr;
+        file_headers_t *deb_extract_list = (file_headers_t *) calloc(1, sizeof(file_headers_t));
 
-        FILE *deb_file, *uncompressed_file;
-        ar_headers_t *headers = NULL;
         char *ared_file = NULL;
         char *output_buffer = NULL;
         int gunzip_pid;
 
-        switch (function) {
-                case (extract_info):
-                case (extract_control):
-                case (extract_field):
-                        ared_file = xstrdup("control.tar.gz");
-                        break;
-                default:
-                        ared_file = xstrdup("data.tar.gz");
-                        break;
+        if (extract_function & extract_control_tar_gz) {
+                ared_file = xstrdup("control.tar.gz");
+        }
+        else if (extract_function & extract_data_tar_gz) {              
+                ared_file = xstrdup("data.tar.gz");
         }
 
         /* open the debian package to be worked on */
-        deb_file = wfopen(package_filename, "r");
+        deb_stream = wfopen(package_filename, "r");
 
-        headers = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));       
+        ar_headers = (file_headers_t *) xmalloc(sizeof(file_headers_t));        
         
         /* get a linked list of all ar entries */
-        if ((headers = get_ar_headers(deb_file)) == NULL) {
+        ar_headers = get_ar_headers(deb_stream);
+        if (ar_headers == NULL) {
                 error_msg("Couldnt get ar headers\n");
                 return(NULL);
         }
 
         /* seek to the start of the .tar.gz file within the ar file*/
-        if (seek_ared_file(deb_file, headers, ared_file) == EXIT_FAILURE) {
-                error_msg("Couldnt seek to ar file");
+        fseek(deb_stream, 0, SEEK_SET);
+        if (seek_sub_file(deb_stream, ar_headers, ared_file) == EXIT_FAILURE) {
+                error_msg("Couldnt seek to file %s", ared_file);
         }
 
-        /* open a stream of decompressed data */
-        uncompressed_file = fdopen(gz_open(deb_file, &gunzip_pid), "r");
-
-        if (function & extract_fsys_tarfile) {
-                copy_file_chunk(uncompressed_file, stdout, -1);
-        } else {
-                FILE *output;
+        /* get a linked list of all tar entries */
+        tar_headers = get_tar_gz_headers(deb_stream);
+        if (tar_headers == NULL) {
+                error_msg("Couldnt get tar headers\n");
+                return(NULL);
+        }
 
-                if (function & extract_contents_to_file) {
-                        output = wfopen(argument, "w");
-                } else {
-                        output = stdout;
+        if (extract_function & extract_one_to_buffer) {
+                list_ptr = tar_headers;
+                while (list_ptr != NULL) {
+                        if (strcmp(filename, list_ptr->name) == 0) {
+                                deb_extract_list = append_archive_list(deb_extract_list, list_ptr);
+                                break;
+                        }
+                        list_ptr = list_ptr->next;
                 }
+        } else {
+                deb_extract_list = tar_headers;
+        }
 
-                output_buffer = untar(uncompressed_file, output, function, argument, argument2);
-                if (output != stdout) {
-                        fclose(output);
-                }
+        /* seek to the start of the .tar.gz file within the ar file*/
+        if (seek_sub_file(deb_stream, ar_headers, ared_file) == EXIT_FAILURE) {
+                error_msg("Couldnt seek to ar file");
         }
+
+        /* open a stream of decompressed data */
+        uncompressed_stream = fdopen(gz_open(deb_stream, &gunzip_pid), "r");
+
+        output_buffer = extract_archive(uncompressed_stream, out_stream, deb_extract_list, extract_function, prefix);
+
         gz_close(gunzip_pid);
-        fclose(deb_file);
-        fclose(uncompressed_file);
+        fclose(deb_stream);
+        fclose(uncompressed_stream);
         free(ared_file);
 
         return(output_buffer);
diff --git a/libbb/get_ar_headers.c b/libbb/get_ar_headers.c
index 151caafe1..414498b4f 100644
--- a/libbb/get_ar_headers.c
+++ b/libbb/get_ar_headers.c
@@ -30,7 +30,7 @@
 #include <unistd.h>
 #include "libbb.h"
 
-extern ar_headers_t *get_ar_headers(FILE *in_file)
+file_headers_t *get_ar_headers(FILE *in_file)
 {
         typedef struct raw_ar_header_s {        /* Byte Offset */
                 char name[16];  /*  0-15 */
@@ -44,7 +44,7 @@ extern ar_headers_t *get_ar_headers(FILE *in_file)
 
         raw_ar_header_t raw_ar_header;
 
-        ar_headers_t *ar_list, *ar_tmp, *ar_entry;
+        file_headers_t *ar_list, *ar_entry;
         char ar_magic[8];
         char *long_name=NULL;
         
@@ -59,10 +59,10 @@ extern ar_headers_t *get_ar_headers(FILE *in_file)
                 return(NULL);
         }
         
-        ar_list = (ar_headers_t *) xcalloc(1, sizeof(ar_headers_t));
+        ar_list = (file_headers_t *) xcalloc(1, sizeof(file_headers_t));
 
         while (fread((char *) &raw_ar_header, 1, 60, in_file) == 60) {
-                ar_entry = (ar_headers_t *) xcalloc(1, sizeof(ar_headers_t));
+                ar_entry = (file_headers_t *) xcalloc(1, sizeof(file_headers_t));
                 /* check the end of header markers are valid */
                 if ((raw_ar_header.fmag[0] != '`') || (raw_ar_header.fmag[1] != '\n')) {
                         char newline;
@@ -113,12 +113,7 @@ extern ar_headers_t *get_ar_headers(FILE *in_file)
 
                 fseek(in_file, (off_t) ar_entry->size, SEEK_CUR);
 
-                ar_tmp = (ar_headers_t *) xcalloc(1, sizeof(ar_headers_t));
-                *ar_tmp = *ar_list;
-                *ar_list = *ar_entry;
-                free(ar_entry);
-                ar_list->next = ar_tmp;
+                ar_list = append_archive_list(ar_list, ar_entry);
         }
-
         return(ar_list);
 }
diff --git a/libbb/libbb.h b/libbb/libbb.h
index f99d25780..f24a38109 100644
--- a/libbb/libbb.h
+++ b/libbb/libbb.h
@@ -213,36 +213,41 @@ char *xreadlink(const char *path);
 char *concat_path_file(const char *path, const char *filename);
 char *last_char_is(const char *s, int c);
 
-typedef struct ar_headers_s {
+typedef struct file_headers_s {
         char *name;
+        char *link_name;
         off_t size;
         uid_t uid;
         gid_t gid;
         mode_t mode;
         time_t mtime;
         off_t offset;
-        struct ar_headers_s *next;
-} ar_headers_t;
-extern ar_headers_t *get_ar_headers(FILE *in_file);
-extern int seek_ared_file(FILE *in_file, ar_headers_t *headers, const char *tar_gz_file);
-
-typedef enum extract_function_e {
-        extract_contents = 1,
-        extract_control = 2,
-        extract_info = 4,
-        extract_extract = 8,
-        extract_verbose_extract = 16,
-        extract_list = 32,
-        extract_fsys_tarfile = 64,
-        extract_field = 128,
-        extract_contents_to_file = 256
-} extract_function_t;
-extern char *deb_extract(const char *package_filename, int function,
-        const char *argument, const char *argument2);
-extern char *untar(FILE *src_tar_file, FILE *output, int untar_function,
-        const char *argument, const char *file_prefix);
-extern char *read_text_file_to_buffer(FILE *src_file);
-extern char *read_package_field(const char *package_buffer);
+        dev_t device;
+        struct file_headers_s *next;
+} file_headers_t;
+file_headers_t *get_ar_headers(FILE *in_file);
+file_headers_t *get_tar_headers(FILE *tar_stream);
+file_headers_t *get_tar_gz_headers(FILE *compressed_stream);
+file_headers_t *append_archive_list(file_headers_t *head, file_headers_t *tail_entry);
+file_headers_t *add_from_archive_list(file_headers_t *master_list, file_headers_t *new_list, const char *name);
+
+enum extract_functions_e {
+        extract_verbose_list = 1,
+        extract_list = 2,
+        extract_one_to_buffer = 4,
+        extract_to_stdout = 8,
+        extract_all_to_fs = 16,
+        extract_preserve_date = 32,
+        extract_data_tar_gz = 64,
+        extract_control_tar_gz = 128,
+        extract_unzip_only = 256
+};
+char *extract_archive(FILE *src_stream, FILE *out_stream, file_headers_t *extract_headers, int function, const char *prefix);
+char *deb_extract(const char *package_filename, FILE *out_stream, const int function,
+        const char *prefix, const char *filename);
+char *read_package_field(const char *package_buffer);
+int seek_sub_file(FILE *in_file, file_headers_t *headers, const char *tar_gz_file);
+char *fgets_str(FILE *file, const char *terminating_string);
 
 extern int unzip(FILE *l_in_file, FILE *l_out_file);
 extern void gz_close(int gunzip_pid);