check if pointer is != NULL before dereferencing it (Coverity CID 40)

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

diff --git a/crypto/dso/dso_dlfcn.c b/crypto/dso/dso_dlfcn.c
index 2b8f3ee4d8b0ccfb644e6ffc0f6d2587227ee554..979fca80654f850d7bad358fd9fe426971111cc7 100644 (file)
--- a/crypto/dso/dso_dlfcn.c
+++ b/crypto/dso/dso_dlfcn.c
@@ -56,6 +56,17 @@
  *
  */
 
+/* We need to do this early, because stdio.h includes the header files
+   that handle _GNU_SOURCE and other similar macros.  Defining it later
+   is simply too late, because those headers are protected from re-
+   inclusion.  */
+#ifdef __linux
+# ifndef _GNU_SOURCE
+#  define _GNU_SOURCE  /* make sure dladdr is declared */
+# endif
+# define HAVE_DLINFO 1
+#endif
+
 #include <stdio.h>
 #include "cryptlib.h"
 #include <openssl/dso.h>
@@ -68,6 +79,7 @@ DSO_METHOD *DSO_METHOD_dlfcn(void)
 #else
 
 #ifdef HAVE_DLFCN_H
+
 #include <dlfcn.h>
 #endif
 
@@ -87,6 +99,8 @@ static long dlfcn_ctrl(DSO *dso, int cmd, long larg, void *parg);
 static char *dlfcn_name_converter(DSO *dso, const char *filename);
 static char *dlfcn_merger(DSO *dso, const char *filespec1,
        const char *filespec2);
+static int dlfcn_pathbyaddr(void *addr,char *path,int sz);
+static void *dlfcn_globallookup(const char *name);
 
 static DSO_METHOD dso_meth_dlfcn = {
        "OpenSSL 'dlfcn' shared library method",
@@ -103,7 +117,9 @@ static DSO_METHOD dso_meth_dlfcn = {
        dlfcn_name_converter,
        dlfcn_merger,
        NULL, /* init */
-       NULL  /* finish */
+       NULL, /* finish */
+       dlfcn_pathbyaddr,
+       dlfcn_globallookup
        };
 
 DSO_METHOD *DSO_METHOD_dlfcn(void)
@@ -118,6 +134,7 @@ DSO_METHOD *DSO_METHOD_dlfcn(void)
  * be hacked further relatively easily to deal with cases as we find
  * them. Initially this is to cope with OpenBSD. */
 #if defined(__OpenBSD__) || defined(__NetBSD__)
+#      define HAVE_DLINFO 1
 #      ifdef DL_LAZY
 #              define DLOPEN_FLAG DL_LAZY
 #      else
@@ -129,6 +146,7 @@ DSO_METHOD *DSO_METHOD_dlfcn(void)
 #      endif
 #else
 #      ifdef OPENSSL_SYS_SUNOS
+#              define HAVE_DLINFO 1
 #              define DLOPEN_FLAG 1
 #      else
 #              define DLOPEN_FLAG RTLD_NOW /* Hope this works everywhere else */
@@ -237,7 +255,7 @@ static void *dlfcn_bind_var(DSO *dso, const char *symname)
 static DSO_FUNC_TYPE dlfcn_bind_func(DSO *dso, const char *symname)
        {
        void *ptr;
-       DSO_FUNC_TYPE sym;
+       DSO_FUNC_TYPE sym, *tsym = &sym;
 
        if((dso == NULL) || (symname == NULL))
                {
@@ -255,7 +273,7 @@ static DSO_FUNC_TYPE dlfcn_bind_func(DSO *dso, const char *symname)
                DSOerr(DSO_F_DLFCN_BIND_FUNC,DSO_R_NULL_HANDLE);
                return(NULL);
                }
-       *(void **)(&sym) = dlsym(ptr, symname);
+       *(void **)(tsym) = dlsym(ptr, symname);
        if(sym == NULL)
                {
                DSOerr(DSO_F_DLFCN_BIND_FUNC,DSO_R_SYM_FAILURE);
@@ -278,13 +296,12 @@ static char *dlfcn_merger(DSO *dso, const char *filespec1,
                }
        /* If the first file specification is a rooted path, it rules.
           same goes if the second file specification is missing. */
-       if (!filespec2 || filespec1[0] == '/')
+       if (!filespec2 || (filespec1 != NULL && filespec1[0] == '/'))
                {
                merged = OPENSSL_malloc(strlen(filespec1) + 1);
                if(!merged)
                        {
-                       DSOerr(DSO_F_DLFCN_MERGER,
-                               ERR_R_MALLOC_FAILURE);
+                       DSOerr(DSO_F_DLFCN_MERGER, ERR_R_MALLOC_FAILURE);
                        return(NULL);
                        }
                strcpy(merged, filespec1);
@@ -310,7 +327,7 @@ static char *dlfcn_merger(DSO *dso, const char *filespec1,
                {
                int spec2len, len;
 
-               spec2len = (filespec2 ? strlen(filespec2) : 0);
+               spec2len = strlen(filespec2);
                len = spec2len + (filespec1 ? strlen(filespec1) : 0);
 
                if(filespec2 && filespec2[spec2len - 1] == '/')
@@ -366,4 +383,84 @@ static char *dlfcn_name_converter(DSO *dso, const char *filename)
        return(translated);
        }
 
+#ifdef __sgi
+/*
+This is a quote from IRIX manual for dladdr(3c):
+
+     <dlfcn.h> does not contain a prototype for dladdr or definition of
+     Dl_info.  The #include <dlfcn.h>  in the SYNOPSIS line is traditional,
+     but contains no dladdr prototype and no IRIX library contains an
+     implementation.  Write your own declaration based on the code below.
+
+     The following code is dependent on internal interfaces that are not
+     part of the IRIX compatibility guarantee; however, there is no future
+     intention to change this interface, so on a practical level, the code
+     below is safe to use on IRIX.
+*/
+#define HAVE_DLINFO 1
+#include <rld_interface.h>
+#ifndef _RLD_INTERFACE_DLFCN_H_DLADDR
+#define _RLD_INTERFACE_DLFCN_H_DLADDR
+typedef struct Dl_info {
+    const char * dli_fname;
+    void       * dli_fbase;
+    const char * dli_sname;
+    void       * dli_saddr;
+    int          dli_version;
+    int          dli_reserved1;
+    long         dli_reserved[4];
+} Dl_info;
+#else
+typedef struct Dl_info Dl_info;
+#endif
+#define _RLD_DLADDR             14
+
+static int dladdr(void *address, Dl_info *dl)
+{
+       void *v;
+       v = _rld_new_interface(_RLD_DLADDR,address,dl);
+       return (int)v;
+}
+#endif /* __sgi */
+
+static int dlfcn_pathbyaddr(void *addr,char *path,int sz)
+       {
+#ifdef HAVE_DLINFO
+       Dl_info dli;
+       int len;
+
+       if (addr == NULL)
+               {
+               union   { int(*f)(void*,char*,int); void *p; } t =
+                       { dlfcn_pathbyaddr };
+               addr = t.p;
+               }
+
+       if (dladdr(addr,&dli))
+               {
+               len = (int)strlen(dli.dli_fname);
+               if (sz <= 0) return len+1;
+               if (len >= sz) len=sz-1;
+               memcpy(path,dli.dli_fname,len);
+               path[len++]=0;
+               return len;
+               }
+
+       ERR_add_error_data(4, "dlfcn_pathbyaddr(): ", dlerror());
+#endif
+       return -1;
+       }
+
+static void *dlfcn_globallookup(const char *name)
+       {
+       void *ret = NULL,*handle = dlopen(NULL,RTLD_LAZY);
+       
+       if (handle)
+               {
+               ret = dlsym(handle,name);
+               dlclose(handle);
+               }
+
+       return ret;
+       }
 #endif /* DSO_DLFCN */