Added fatelf-remove utility.

icculus · Sep 24, 2009 · a5a2097 · a5a2097
1 parent 0468475
commit a5a2097
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diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -8,6 +8,7 @@ ADD_EXECUTABLE(fatelf-glue utils/fatelf-glue.c utils/fatelf-utils.c)
 ADD_EXECUTABLE(fatelf-info utils/fatelf-info.c utils/fatelf-utils.c)
 ADD_EXECUTABLE(fatelf-extract utils/fatelf-extract.c utils/fatelf-utils.c)
 ADD_EXECUTABLE(fatelf-replace utils/fatelf-replace.c utils/fatelf-utils.c)
+ADD_EXECUTABLE(fatelf-remove utils/fatelf-remove.c utils/fatelf-utils.c)
 
 # end of CMakeLists.txt ...
 
diff --git a/utils/fatelf-remove.c b/utils/fatelf-remove.c
@@ -0,0 +1,75 @@
+/**
+ * FatELF; support multiple ELF binaries in one file.
+ *
+ * Please see the file LICENSE.txt in the source's root directory.
+ *
+ *  This file written by Ryan C. Gordon.
+ */
+
+#define FATELF_UTILS 1
+#include "fatelf-utils.h"
+
+static int fatelf_remove(const char *out, const char *fname,
+                         const char *target)
+{
+    const int fd = xopen(fname, O_RDONLY, 0755);
+    FATELF_header *header = xread_fatelf_header(fname, fd);
+    const int idx = xfind_fatelf_record(header, target);
+    const int outfd = xopen(out, O_WRONLY | O_CREAT | O_TRUNC, 0755);
+    uint64_t offset = FATELF_DISK_FORMAT_SIZE(((int)header->num_records));
+    int i;
+
+    unlink_on_xfail = out;
+
+    // pad out some bytes for the header we'll write at the end...
+    xwrite_zeros(out, outfd, (size_t) offset);
+
+    for (i = 0; i < ((int) header->num_records); i++)
+    {
+        if (i != idx)  // not the thing we're removing?
+        {
+            const uint64_t binary_offset = align_to_page(offset);
+            FATELF_record *rec = &header->records[i];
+
+            // append this binary to the final file, padded to page alignment.
+            xwrite_zeros(out, outfd, (size_t) (binary_offset - offset));
+            xcopyfile_range(fname, fd, out, outfd, binary_offset, rec->size);
+
+            rec->offset = binary_offset;
+            offset = binary_offset + rec->size;
+        } // if
+    } // for
+
+    // remove the record we chopped out.
+    header->num_records--;
+    if (idx < ((int) header->num_records))
+    {
+        void *dst = &header->records[idx];
+        const void *src = &header->records[idx+1];
+        const size_t count = (header->num_records - idx);
+        memmove(dst, src, sizeof (FATELF_record) * count);
+    } // if
+
+    // Write the actual FatELF header now...
+    xwrite_fatelf_header(out, outfd, header);
+
+    xclose(out, outfd);
+    xclose(fname, fd);
+    free(header);
+
+    unlink_on_xfail = NULL;
+
+    return 0;  // success.
+} // fatelf_remove
+
+
+int main(int argc, const char **argv)
+{
+    xfatelf_init(argc, argv);
+    if (argc != 4)  // this could stand to use getopt(), later.
+        xfail("USAGE: %s <out> <in> <target>", argv[0]);
+    return fatelf_remove(argv[1], argv[2], argv[3]);
+} // main
+
+// end of fatelf-remove.c ...
+