X-Git-Url: https://git.armaanb.net/?a=blobdiff_plain;f=env.c;h=3e8b95d44c7c5c67096f3438278fc0fa4f26982c;hb=38e072b353f5b1325bbf52dfb759fe49ff6ef0f7;hp=f25d21f7abc9f0d8b73ca1f2f4ccde926fcfcc2a;hpb=aedbe76e8443757d8553a35fdc217722dcd1470b;p=opendoas.git

diff --git a/env.c b/env.c
index f25d21f..3e8b95d 100644
--- a/env.c
+++ b/env.c
@@ -39,19 +39,38 @@ struct env {
 	u_int count;
 };
 
-int
+static int
 envcmp(struct envnode *a, struct envnode *b)
 {
 	return strcmp(a->key, b->key);
 }
 RB_GENERATE_STATIC(envtree, envnode, node, envcmp)
 
-struct env *createenv(char **);
-struct env *filterenv(struct env *, struct rule *);
-char **flattenenv(struct env *);
+static struct envnode *
+createnode(const char *key, const char *value)
+{
+	struct envnode *node;
+
+	node = malloc(sizeof(*node));
+	if (!node)
+		err(1, NULL);
+	node->key = strdup(key);
+	node->value = strdup(value);
+	if (!node->key || !node->value)
+		err(1, NULL);
+	return node;
+}
 
-struct env *
-createenv(char **envp)
+static void
+freenode(struct envnode *node)
+{
+	free((char *)node->key);
+	free((char *)node->value);
+	free(node);
+}
+
+static struct env *
+createenv(const struct rule *rule)
 {
 	struct env *env;
 	u_int i;
@@ -62,34 +81,40 @@ createenv(char **envp)
 	RB_INIT(&env->root);
 	env->count = 0;
 
-	for (i = 0; envp[i] != NULL; i++) {
-		struct envnode *node;
-		const char *e, *eq;
-
-		e = envp[i];
-
-		if ((eq = strchr(e, '=')) == NULL || eq == e)
-			continue;
-		node = malloc(sizeof(*node));
-		if (!node)
-			err(1, NULL);
-		node->key = strndup(envp[i], eq - e);
-		node->value = strdup(eq + 1);
-		if (!node->key || !node->value)
-			err(1, NULL);
-		if (RB_FIND(envtree, &env->root, node)) {
-			free((char *)node->key);
-			free((char *)node->value);
-			free(node);
-		} else {
-			RB_INSERT(envtree, &env->root, node);
-			env->count++;
+	if (rule->options & KEEPENV) {
+		extern char **environ;
+
+		for (i = 0; environ[i] != NULL; i++) {
+			struct envnode *node;
+			const char *e, *eq;
+			size_t len;
+			char keybuf[1024];
+
+			e = environ[i];
+
+			/* ignore invalid or overlong names */
+			if ((eq = strchr(e, '=')) == NULL || eq == e)
+				continue;
+			len = eq - e;
+			if (len > sizeof(keybuf) - 1)
+				continue;
+			memcpy(keybuf, e, len);
+			keybuf[len] = '\0';
+
+			node = createnode(keybuf, eq + 1);
+			if (RB_INSERT(envtree, &env->root, node)) {
+				/* ignore any later duplicates */
+				freenode(node);
+			} else {
+				env->count++;
+			}
 		}
 	}
+
 	return env;
 }
 
-char **
+static char **
 flattenenv(struct env *env)
 {
 	char **envp;
@@ -110,72 +135,74 @@ flattenenv(struct env *env)
 }
 
 static void
-copyenv(struct env *orig, struct env *copy, const char **envlist)
+fillenv(struct env *env, const char **envlist)
 {
 	struct envnode *node, key;
+	const char *e, *eq;
+	const char *val;
+	char name[1024];
 	u_int i;
+	size_t len;
 
 	for (i = 0; envlist[i]; i++) {
-		key.key = envlist[i];
-		if ((node = RB_FIND(envtree, &orig->root, &key))) {
-			RB_REMOVE(envtree, &orig->root, node);
-			orig->count--;
-			RB_INSERT(envtree, &copy->root, node);
-			copy->count++;
+		e = envlist[i];
+
+		/* parse out env name */
+		if ((eq = strchr(e, '=')) == NULL)
+			len = strlen(e);
+		else
+			len = eq - e;
+		if (len > sizeof(name) - 1)
+			continue;
+		memcpy(name, e, len);
+		name[len] = '\0';
+
+		/* delete previous copies */
+		key.key = name;
+		if (*name == '-')
+			key.key = name + 1;
+		if ((node = RB_FIND(envtree, &env->root, &key))) {
+			RB_REMOVE(envtree, &env->root, node);
+			freenode(node);
+			env->count--;
+		}
+		if (*name == '-')
+			continue;
+
+		/* assign value or inherit from environ */
+		if (eq) {
+			val = eq + 1;
+			if (*val == '$')
+				val = getenv(val + 1);
+		} else {
+			val = getenv(name);
+		}
+		/* at last, we have something to insert */
+		if (val) {
+			node = createnode(name, val);
+			RB_INSERT(envtree, &env->root, node);
+			env->count++;
 		}
 	}
 }
 
-struct env *
-filterenv(struct env *orig, struct rule *rule)
+char **
+prepenv(const struct rule *rule)
 {
-	const char *safeset[] = {
+	static const char *safeset[] = {
 		"DISPLAY", "HOME", "LOGNAME", "MAIL",
 		"PATH", "TERM", "USER", "USERNAME",
 		NULL
 	};
-	const char *badset[] = {
-		"ENV",
-		NULL
-	};
-	struct env *copy;
-	struct envnode *node, key;
-	u_int i;
-
-	if ((rule->options & KEEPENV) && !rule->envlist) {
-		for (i = 0; badset[i]; i++) {
-			key.key = badset[i];
-			if ((node = RB_FIND(envtree, &orig->root, &key))) {
-				RB_REMOVE(envtree, &orig->root, node);
-				free((char *)node->key);
-				free((char *)node->value);
-				free(node);
-				orig->count--;
-			}
-		}
-		return orig;
-	}
+	struct env *env;
 
-	copy = malloc(sizeof(*copy));
-	if (!copy)
-		err(1, NULL);
-	RB_INIT(&copy->root);
-	copy->count = 0;
+	env = createenv(rule);
 
+	/* if we started with blank, fill some defaults then apply rules */
+	if (!(rule->options & KEEPENV))
+		fillenv(env, safeset);
 	if (rule->envlist)
-		copyenv(orig, copy, rule->envlist);
-	copyenv(orig, copy, safeset);
+		fillenv(env, rule->envlist);
 
-	return copy;
-}
-
-char **
-prepenv(struct rule *rule)
-{
-	extern char **environ;
-	struct env *env;
-	
-	env = createenv(environ);
-	env = filterenv(env, rule);
 	return flattenenv(env);
 }