make: do not follow symlinks when resolving blogcfile path

3 files changed, 49 insertions, 10 deletions

diff --git a/src/blogc-make/ctx.c b/src/blogc-make/ctx.c
index b8b7bb6..423b334 100644
--- a/src/blogc-make/ctx.c
+++ b/src/blogc-make/ctx.c
@@ -172,22 +172,21 @@ bm_ctx_new(bm_ctx_t *base, const char *settings_file, const char *argv0,
     if (settings_file == NULL || err == NULL || *err != NULL)
         return NULL;
 
-    char real_filename[PATH_MAX];
-    if (NULL == realpath(settings_file, real_filename)) {
-        *err = bc_error_new_printf(BLOGC_MAKE_ERROR_SETTINGS,
-            "Failed to resolve settings file (%s): %s", settings_file,
-            strerror(errno));
+    char *abs_filename = bm_abspath(settings_file, err);
+    if (*err != NULL)
         return NULL;
-    }
 
     size_t content_len;
-    char *content = bc_file_get_contents(real_filename, true, &content_len,
+    char *content = bc_file_get_contents(abs_filename, true, &content_len,
         err);
-    if (*err != NULL)
+    if (*err != NULL) {
+        free(abs_filename);
         return NULL;
+    }
 
     bm_settings_t *settings = bm_settings_parse(content, content_len, err);
     if (settings == NULL || *err != NULL) {
+        free(abs_filename);
         free(content);
         return NULL;
     }
@@ -208,6 +207,7 @@ bm_ctx_new(bm_ctx_t *base, const char *settings_file, const char *argv0,
         atom_template = bm_atom_deploy(settings, err);
         atom_template_tmp = true;
         if (*err != NULL) {
+            free(abs_filename);
             bm_settings_free(settings);
             return NULL;
         }
@@ -228,8 +228,9 @@ bm_ctx_new(bm_ctx_t *base, const char *settings_file, const char *argv0,
     }
     rv->settings = settings;
 
-    rv->settings_fctx = bm_filectx_new(rv, real_filename, NULL, NULL);
-    rv->root_dir = bc_strdup(dirname(real_filename));
+    rv->settings_fctx = bm_filectx_new(rv, abs_filename, NULL, NULL);
+    rv->root_dir = bc_strdup(dirname(abs_filename));
+    free(abs_filename);
 
     const char *output_dir = getenv("OUTPUT_DIR");
     rv->short_output_dir = bc_strdup(output_dir != NULL ? output_dir : "_build");
diff --git a/src/blogc-make/utils.c b/src/blogc-make/utils.c
index 0c984f6..91b7b53 100644
--- a/src/blogc-make/utils.c
+++ b/src/blogc-make/utils.c
@@ -6,10 +6,18 @@
  * See the file LICENSE.
  */
 
+#include <errno.h>
+#include <limits.h>
 #include <stdbool.h>
 #include <string.h>
+#include <unistd.h>
+#include "../common/error.h"
 #include "../common/utils.h"
 
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
+
 
 char*
 bm_generate_filename(const char *dir, const char *prefix, const char *fname,
@@ -59,3 +67,30 @@ bm_generate_filename(const char *dir, const char *prefix, const char *fname,
 
     return bc_string_free(rv, false);
 }
+
+
+char*
+bm_abspath(const char *path, bc_error_t **err)
+{
+    if (err == NULL || *err != NULL)
+        return NULL;
+
+    if (path[0] == '/') {
+        return bc_strdup(path);
+    }
+
+    char cwd[PATH_MAX];
+    if (NULL == getcwd(cwd, sizeof(cwd))) {
+        *err = bc_error_new_printf(BLOGC_MAKE_ERROR_UTILS,
+            "Failed to detect absolute path (%s): %s", path, strerror(errno));
+        return NULL;
+    }
+
+    if (cwd[0] != '/') {
+        *err = bc_error_new_printf(BLOGC_MAKE_ERROR_UTILS,
+            "Failed to get current working directory: %s", cwd);
+        return NULL;
+    }
+
+    return bc_strdup_printf("%s/%s", cwd, path);
+}
diff --git a/src/blogc-make/utils.h b/src/blogc-make/utils.h
index a3dfea0..5353c01 100644
--- a/src/blogc-make/utils.h
+++ b/src/blogc-make/utils.h
@@ -9,7 +9,10 @@
 #ifndef _MAKE_UTILS_H
 #define _MAKE_UTILS_H
 
+#include "../common/error.h"
+
 char* bm_generate_filename(const char *dir, const char *prefix, const char *fname,
     const char *ext);
+char* bm_abspath(const char *path, bc_error_t **err);
 
 #endif /* _MAKE_UTILS_H */