Refactor get_elf_section_offset_and_length

include/appimage/appimage.h

@@ -144,6 +144,11 @@ bool appimage_type2_digest_md5(const char* fname, char* digest);
  */
 char* appimage_hexlify(const char* bytes, size_t numBytes);
 
+/*
+ * Return the offset, and the length of an ELF section with a given name in a given ELF file
+ */
+bool appimage_get_elf_section_offset_and_length(const char* fname, const char* section_name, unsigned long* offset, unsigned long* length);
+
 #ifdef __cplusplus
 }
 #endif

src/appimagetool.c

@@ -835,7 +835,13 @@ main (int argc, char *argv[])
 
             unsigned long ui_offset = 0;
             unsigned long ui_length = 0;
-            get_elf_section_offset_and_length(destination, ".upd_info", &ui_offset, &ui_length);
+
+            bool rv = appimage_get_elf_section_offset_and_length(destination, ".upd_info", &ui_offset, &ui_length);
+
+            if (!rv || ui_offset == 0 || ui_length == 0) {
+                die("Could not find section .upd_info in runtime");
+            }
+
             if(verbose) {
                 printf("ui_offset: %lu\n", ui_offset);
                 printf("ui_length: %lu\n", ui_length);
@@ -864,9 +870,9 @@ main (int argc, char *argv[])
             unsigned long digest_md5_offset = 0;
             unsigned long digest_md5_length = 0;
 
-            int rv = get_elf_section_offset_and_length(destination, ".digest_md5", &digest_md5_offset, &digest_md5_length);
+            bool rv = appimage_get_elf_section_offset_and_length(destination, ".digest_md5", &digest_md5_offset, &digest_md5_length);
 
-            if (rv != 0 || digest_md5_offset == 0 || digest_md5_length == 0) {
+            if (!rv || digest_md5_offset == 0 || digest_md5_length == 0) {
                 die("Could not find section .digest_md5 in runtime");
             }
 
@@ -1020,9 +1026,9 @@ main (int argc, char *argv[])
                     unsigned long sig_offset = 0;
                     unsigned long sig_length = 0;
 
-                    int rv = get_elf_section_offset_and_length(destination, ".sha256_sig", &sig_offset, &sig_length);
+                    bool rv = appimage_get_elf_section_offset_and_length(destination, ".sha256_sig", &sig_offset, &sig_length);
 
-                    if (rv != 0 || sig_offset == 0 || sig_length == 0) {
+                    if (!rv || sig_offset == 0 || sig_length == 0) {
                         die("Could not find section .sha256_sig in runtime");
                     }
 
@@ -1120,8 +1126,13 @@ main (int argc, char *argv[])
                 {
                     sprintf(command, "%s --batch --export --armor %s", gpg2_path, sign_key);
 
-                    unsigned long key_offset, key_length;
-                    int rv = get_elf_section_offset_and_length(destination, ".sig_key", &key_offset, &key_length);
+                    unsigned long key_offset = 0, key_length = 0;
+
+                    bool rv = appimage_get_elf_section_offset_and_length(destination, ".sig_key", &key_offset, &key_length);
+
+                    if (!rv || key_offset == 0 || key_length == 0) {
+                        die("Could not find section .sig_key in runtime");
+                    }
 
                     if (verbose) {
                         printf("key_offset: %lu\n", key_offset);

src/appimagetool_shared.c

@@ -61,15 +61,15 @@ int appimage_get_type(const char* path, bool verbose)
 bool appimage_type2_digest_md5(const char* path, char* digest) {
     // skip digest, signature and key sections in digest calculation
     unsigned long digest_md5_offset = 0, digest_md5_length = 0;
-    if (get_elf_section_offset_and_length(path, ".digest_md5", &digest_md5_offset, &digest_md5_length) != 0)
+    if (!appimage_get_elf_section_offset_and_length(path, ".digest_md5", &digest_md5_offset, &digest_md5_length))
         return false;
 
     unsigned long signature_offset = 0, signature_length = 0;
-    if (get_elf_section_offset_and_length(path, ".sha256_sig", &signature_offset, &signature_length) != 0)
+    if (!appimage_get_elf_section_offset_and_length(path, ".sha256_sig", &signature_offset, &signature_length))
         return false;
 
     unsigned long sig_key_offset = 0, sig_key_length = 0;
-    if (get_elf_section_offset_and_length(path, ".sig_key", &sig_key_offset, &sig_key_length) != 0)
+    if (!appimage_get_elf_section_offset_and_length(path, ".sig_key", &sig_key_offset, &sig_key_length))
         return false;
 
     GChecksum *checksum = g_checksum_new(G_CHECKSUM_MD5);

src/digest_md5.c

@@ -49,7 +49,7 @@ int main(int argc, char* argv[]) {
 
     static const char section_name[] = ".digest_md5";
 
-    if (get_elf_section_offset_and_length(fname, section_name, &offset, &length) != 0 || offset == 0 || length == 0) {
+    if (!appimage_get_elf_section_offset_and_length(fname, section_name, &offset, &length) || offset == 0 || length == 0) {
         fprintf(stderr, "Could not find %s section in file\n", section_name);
         return 1;
     }

src/getsection.c

@@ -2,13 +2,13 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/mman.h>
+#include <stdbool.h>
 #include <string.h>
 #include <unistd.h>
 #include "light_elf.h"
 
 /* Return the offset, and the length of an ELF section with a given name in a given ELF file */
-int get_elf_section_offset_and_length(const char* fname, const char* section_name, unsigned long* offset,
-                                      unsigned long* length) {
+bool appimage_get_elf_section_offset_and_length(const char* fname, const char* section_name, unsigned long* offset, unsigned long* length) {
     uint8_t* data;
     int i;
     int fd = open(fname, O_RDONLY);
@@ -51,11 +51,11 @@ int get_elf_section_offset_and_length(const char* fname, const char* section_nam
     } else {
         sprintf(stderr, "Platforms other than 32-bit/64-bit are currently not supported!");
         munmap(data, map_size);
-        return 2;
+        return false;
     }
 
     munmap(data, map_size);
-    return 0;
+    return true;
 }
 
 char* read_file_offset_length(const char* fname, unsigned long offset, unsigned long length) {

src/getsection.h

@@ -1,9 +1,6 @@
 #ifndef GETSECTION_H
 #define GETSECTION_H
 
-/* Return the offset, and the length of an ELF section with a given name in a given ELF file */
-int get_elf_section_offset_and_length(const char* fname, const char* section_name, unsigned long *offset, unsigned long *length);
-
 int print_hex(const char* fname, unsigned long offset, unsigned long length);
 
 int print_binary(const char* fname, unsigned long offset, unsigned long length);