1 files changed, 57 insertions, 0 deletions

diff --git a/src/data_management.c b/src/data_management.c
index 1ee8134..a6d8a0b 100644
--- a/src/data_management.c
+++ b/src/data_management.c
@@ -9,7 +9,10 @@
 #include <string.h>
 #include <errno.h>
 #include <dirent.h>
+#include <unistd.h>
+#include <stdbool.h>
 #include <sys/stat.h>
+#include <sys/types.h>
 
 #include "output.h"
 #include "data_management.h"
@@ -50,6 +53,7 @@ inline struct list_node *create_node(char *fname, struct stat *ln_stat) {
         length = 255;
     }
     node->next = NULL;
+    node->symlink_target = NULL;
     explicit_bzero(node->fname, 256);
     memcpy(node->fname, fname, length);
     memcpy(&(node->ln_stat), ln_stat, sizeof(struct stat));
@@ -64,10 +68,16 @@ inline void destroy_list(struct list_head *list) {
     while (list->first != NULL) {
         ptr = list->first->next;
         if (ptr == NULL) {
+            if (list->first->symlink_target != NULL) {
+                free(list->first->symlink_target);
+            }
             free(list->first);
             break;
         }
         list->first->next = ptr->next;
+        if (ptr->symlink_target != NULL) {
+            free(ptr->symlink_target);
+        }
         free(ptr);
     }
     free(list);
@@ -193,6 +203,35 @@ inline struct list_head *create_list_sort_reversed(struct list_head *list) {
     return lh;
 }
 
+inline char *get_symlink_target_name(char *symlink, struct stat st) {
+    char *name = NULL;
+    ssize_t name_length = 0;
+    size_t tmp = 0;
+
+    if ( symlink == NULL || (! S_ISLNK(st.st_mode)) ) {
+        return NULL;
+    }
+
+    /* Suppressing warning __off_t to size_t only with the failsafe check */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wsign-conversion"
+    tmp = ( (st.st_size<0) ? 0 : st.st_size+1 );
+#pragma GCC diagnostic pop
+    if (tmp == 0) { return NULL; }
+
+    if ((name = calloc(tmp, sizeof(char))) == NULL) {
+        LOGERR("ERROR: Failed to allocate heap memory.\n");
+        return NULL;
+    }
+
+    if ((name_length = readlink(symlink, name, tmp)) == -1) {
+        LOGERR("ERROR: readlink(\"%s\", name, %lu) failed: %s (errno %d)\n",
+            symlink, (st.st_size+1), strerror(errno), errno);
+        free(name);
+        return NULL;
+    }
+    return name;
+}
 
 /* This function contains the only time critical code. The loop over
  * the directory content.
@@ -252,6 +291,9 @@ struct list_head *get_data_from_directory(char *path) {
             LOGERR("ERROR: Skipping entry %s\n", de->d_name);
             continue;
         }
+        if (option_resolve_symlinks && S_ISLNK(stat_res.st_mode)) {
+            tmp->symlink_target = get_symlink_target_name(fullpath, stat_res);
+        }
         /* Performance: Put every node on the stack and do the sorting afterwards */
         tmp->next = lnstack;
         lnstack = tmp;
@@ -286,3 +328,18 @@ struct list_head *get_data_from_directory(char *path) {
     return list;
 }
 
+bool contains_resolved_symlinks(struct list_head *list) {
+    struct list_node *ptr = NULL;
+
+    if (list == NULL) { return false; }
+
+    ptr = list->first;
+    while (ptr != NULL) {
+        if (ptr->symlink_target != NULL)
+            return true;
+        ptr = ptr->next;
+    }
+
+    return false;
+}
+