There's an ongoing project to bring some kind of path selection

[thirdparty/openssl.git] / crypto / dso / dso_dlfcn.c

diff --git a/crypto/dso/dso_dlfcn.c b/crypto/dso/dso_dlfcn.c
index 906b4703de71c4f42a210f8706b17a86118cfb83..de88b2fd16d033da6795271e10fe255de4ee6804 100644 (file)
--- a/crypto/dso/dso_dlfcn.c
+++ b/crypto/dso/dso_dlfcn.c
@@ -1,4 +1,4 @@
-/* dso_dlfcn.c */
+/* dso_dlfcn.c -*- mode:C; c-file-style: "eay" -*- */
 /* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
  * project 2000.
  */
@@ -85,6 +85,8 @@ static int dlfcn_finish(DSO *dso);
 static long dlfcn_ctrl(DSO *dso, int cmd, long larg, void *parg);
 #endif
 static char *dlfcn_name_converter(DSO *dso, const char *filename);
+static char *dlfcn_merger(DSO *dso, const char *filespec1,
+       const char *filespec2);
 
 static DSO_METHOD dso_meth_dlfcn = {
        "OpenSSL 'dlfcn' shared library method",
@@ -99,6 +101,7 @@ static DSO_METHOD dso_meth_dlfcn = {
 #endif
        NULL, /* ctrl */
        dlfcn_name_converter,
+       dlfcn_merger,
        NULL, /* init */
        NULL  /* finish */
        };
@@ -252,6 +255,73 @@ static DSO_FUNC_TYPE dlfcn_bind_func(DSO *dso, const char *symname)
        return(sym);
        }
 
+static char *dlfcn_merger(DSO *dso, const char *filespec1,
+       const char *filespec2)
+       {
+       char *merged;
+
+       if(!filespec1 && !filespec2)
+               {
+               DSOerr(DSO_F_DLFCN_MERGER,
+                               ERR_R_PASSED_NULL_PARAMETER);
+               return(NULL);
+               }
+       /* If the first file specification is a rooted path, it rules.
+          same goes if the second file specification is missing. */
+       if (!filespec2 || filespec1[0] == '/')
+               {
+               merged = OPENSSL_malloc(strlen(filespec1) + 1);
+               if(!merged)
+                       {
+                       DSOerr(DSO_F_DLFCN_MERGER,
+                               ERR_R_MALLOC_FAILURE);
+                       return(NULL);
+                       }
+               strcpy(merged, filespec1);
+               }
+       /* If the first file specification is missing, the second one rules. */
+       else if (!filespec1)
+               {
+               merged = OPENSSL_malloc(strlen(filespec2) + 1);
+               if(!merged)
+                       {
+                       DSOerr(DSO_F_DLFCN_MERGER,
+                               ERR_R_MALLOC_FAILURE);
+                       return(NULL);
+                       }
+               strcpy(merged, filespec2);
+               }
+       else
+               /* This part isn't as trivial as it looks.  It assumes that
+                  the second file specification really is a directory, and
+                  makes no checks whatsoever.  Therefore, the result becomes
+                  the concatenation of filespec2 followed by a slash followed
+                  by filespec1. */
+               {
+               int spec2len, len;
+
+               spec2len = (filespec2 ? strlen(filespec2) : 0);
+               len = spec2len + (filespec1 ? strlen(filespec1) : 0);
+
+               if(filespec2 && filespec2[spec2len - 1] == '/')
+                       {
+                       spec2len--;
+                       len--;
+                       }
+               merged = OPENSSL_malloc(len + 2);
+               if(!merged)
+                       {
+                       DSOerr(DSO_F_DLFCN_MERGER,
+                               ERR_R_MALLOC_FAILURE);
+                       return(NULL);
+                       }
+               strcpy(merged, filespec2);
+               merged[spec2len] = '/';
+               strcpy(&merged[spec2len + 1], filespec1);
+               }
+       return(merged);
+       }
+
 static char *dlfcn_name_converter(DSO *dso, const char *filename)
        {
        char *translated;