From: Todd C. Miller <Todd.Miller@courtesan.com>
Date: Mon, 16 Jul 2007 22:39:42 +0000 (+0000)
Subject: Add sudo_unsetenv() and refactor private env syncing code into sync_env().
X-Git-Tag: SUDO_1_7_0~483
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=436e3b631b61aff260513a5ea25022696614abb7;p=sudo

Add sudo_unsetenv() and refactor private env syncing code into sync_env().
---

diff --git a/env.c b/env.c
index c1a71ea14..792111009 100644
--- a/env.c
+++ b/env.c
@@ -101,7 +101,11 @@ struct environment {
  */
 char **rebuild_env		__P((char **, int, int));
 void sudo_setenv		__P((const char *, const char *, int));
+void sudo_unsetenv		__P((const char *));
 static void insert_env		__P((char *, int));
+static void sync_env		__P((char **));
+
+extern char **environ;		/* global environment */
 
 /*
  * Copy of the sudo-managed environment.
@@ -206,6 +210,29 @@ static const char *initial_keepenv_table[] = {
     NULL
 };
 
+/*
+ * Syncronize our private copy of the environment with what is
+ * in envp.
+ */
+static void
+sync_env(envp)
+    char **envp;
+{
+    size_t evlen;
+    char **ep;
+
+    for (ep = envp; *ep != NULL; ep++)
+	continue;
+    evlen = ep - envp;
+    if (evlen + 1 > env.env_size) {
+	efree(env.envp);
+	env.env_size = evlen + 1 + 128;
+	env.envp = emalloc2(env.env_size, sizeof(char *));
+    }
+    memcpy(env.envp, envp, evlen + 1);
+    env.env_len = evlen;
+}
+
 /*
  * Similar to setenv(3) but operates on sudo's private copy of the environment
  * and it always overwrites.  The dupcheck param determines whether we need
@@ -223,16 +250,45 @@ sudo_setenv(var, val, dupcheck)
     esize = strlen(var) + 1 + strlen(val) + 1;
     estring = emalloc(esize);
 
+    /* Make sure we are operating on the current environment. */
+    if (env.envp != environ)
+	sync_env(environ);
+
+    /* Build environment string and insert it. */
     if (strlcpy(estring, var, esize) >= esize ||
 	strlcat(estring, "=", esize) >= esize ||
 	strlcat(estring, val, esize) >= esize) {
 
 	errorx(1, "internal error, sudo_setenv() overflow");
     }
-
     insert_env(estring, dupcheck);
 }
 
+/*
+ * Similar to unsetenv(3) but operates on sudo's private copy of the
+ * environment.
+ */
+void
+sudo_unsetenv(var)
+    const char *var;
+{
+    char **nep;
+    size_t varlen;
+
+    /* Make sure we are operating on the current environment. */
+    if (env.envp != environ)
+	sync_env(environ);
+
+    varlen = strlen(var);
+    for (nep = env.envp; *nep; nep++) {
+	if (strncmp(var, *nep, varlen) == 0 && *nep[varlen] == '=') {
+	    /* Found it; move everything over by one and update len. */
+	    memmove(nep, nep + 1, env.env_len - (nep - env.envp));
+	    env.env_len--;
+	    return;
+	}
+    }
+}
 
 /*
  * Insert str into env.envp, assumes str has an '=' in it.
@@ -581,24 +637,9 @@ insert_env_vars(envp, env_vars)
     if (env_vars == NULL)
 	return(envp);
 
-    /*
-     * Make sure we still own the environment and steal it back if not.
-     */
-    if (env.envp != envp) {
-	size_t evlen;
-	char **ep;
-
-	for (ep = envp; *ep != NULL; ep++)
-	    continue;
-	evlen = ep - envp;
-	if (evlen + 1 > env.env_size) {
-	    efree(env.envp);
-	    env.env_size = evlen + 1 + 128;
-	    env.envp = emalloc2(env.env_size, sizeof(char *));
-	}
-	memcpy(env.envp, envp, evlen + 1);
-	env.env_len = evlen;
-    }
+    /* Make sure we are operating on the current environment. */
+    if (env.envp != envp)
+	sync_env(envp);
 
     /* Add user-specified environment variables. */
     for (cur = env_vars; cur != NULL; cur = cur->next)
diff --git a/sudo.h b/sudo.h
index e9eb05e5b..3b284935a 100644
--- a/sudo.h
+++ b/sudo.h
@@ -265,6 +265,7 @@ FILE *open_sudoers	__P((const char *, int *));
 void display_privs	__P((VOID *, struct passwd *));
 int display_cmnd	__P((VOID *, struct passwd *));
 void sudo_setenv	__P((const char *, const char *, int));
+void sudo_unsetenv	__P((const char *));
 void sudo_setgrent	__P((void));
 void sudo_endgrent	__P((void));
 void sudo_setpwent	__P((void));