From: Michael Tremer <michael.tremer@ipfire.org>
Date: Fri, 21 May 2021 09:51:53 +0000 (+0000)
Subject: execute: Move setting default environment into libpakfire
X-Git-Tag: 0.9.28~1285^2~111
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a51f0370d5190650147a391382bb109067339700;p=pakfire.git

execute: Move setting default environment into libpakfire

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/libpakfire/execute.c b/src/libpakfire/execute.c
index 13ccce8f4..a75da8e67 100644
--- a/src/libpakfire/execute.c
+++ b/src/libpakfire/execute.c
@@ -41,16 +41,25 @@
 #include <pakfire/types.h>
 #include <pakfire/util.h>
 
+#define ENVIRON_SIZE     128
 #define BUFFER_SIZE      1024 * 64
 #define EPOLL_MAX_EVENTS 2
 #define LDCONFIG         "/sbin/ldconfig"
 
-static char* envp_empty[1] = { NULL };
+// The default environment that will be set for every command
+static const struct environ {
+	const char* key;
+	const char* val;
+} default_environ[] = {
+	{ "LANG", "en_US.utf-8" },
+	{ "TERM", "vt100" },
+	{ NULL, NULL },
+};
 
 struct pakfire_execute {
 	Pakfire pakfire;
 	const char** argv;
-	char** envp;
+	char* envp[ENVIRON_SIZE];
 
 	char cgroup[PATH_MAX];
 
@@ -250,6 +259,50 @@ static int default_logging_callback(Pakfire pakfire, void* data, int priority,
 	return 0;
 }
 
+static int find_environ(struct pakfire_execute* env, const char* key) {
+	if (!key) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	char buffer[strlen(key) + 2];
+	unsigned int i = 0;
+
+	pakfire_string_format(buffer, "%s=", key);
+
+	for (i = 0; env->envp[i]; i++) {
+		if (pakfire_string_startswith(env->envp[i], buffer))
+			return i;
+	}
+
+	// Return -ENOSPC when the environment is full
+	if (i >= ENVIRON_SIZE) {
+		errno = ENOSPC;
+		return -1;
+	}
+
+	// Return the index of the next free slot
+	return i;
+}
+
+static int set_environ(struct pakfire_execute* env, const char* key, const char* value) {
+	// Find the index where to write this value to
+	int idx = find_environ(env, key);
+	if (idx < 0)
+		return idx;
+
+	// Free any previous value
+	if (env->envp[idx])
+		free(env->envp[idx]);
+
+	// Format and set environment variable
+	asprintf(&env->envp[idx], "%s=%s", key, value);
+
+	DEBUG(env->pakfire, "Set environment variable: %s\n", env->envp[idx]);
+
+	return 0;
+}
+
 static int pakfire_execute_fork(void* data) {
 	struct pakfire_execute* env = (struct pakfire_execute*)data;
 
@@ -338,11 +391,11 @@ static int pakfire_execute_fork(void* data) {
 PAKFIRE_EXPORT int pakfire_execute(Pakfire pakfire, const char* argv[], char* envp[],
 		int flags, pakfire_execute_logging_callback logging_callback, void* data) {
 	DIR* cgroupdir = NULL;
+	int r;
 
 	struct pakfire_execute env = {
 		.pakfire = pakfire,
 		.argv = argv,
-		.envp = envp,
 		.cgroup = "pakfire/execute-XXXXXX",
 	};
 
@@ -350,8 +403,12 @@ PAKFIRE_EXPORT int pakfire_execute(Pakfire pakfire, const char* argv[], char* en
 	if (!argv || !argv[0])
 		return -EINVAL;
 
-	if (!env.envp)
-		env.envp = envp_empty;
+	// Set default environment
+	for (const struct environ* e = default_environ; e->key; e++) {
+		r = set_environ(&env, e->key, e->val);
+		if (r)
+			goto ERROR;
+	}
 
 	if (!logging_callback)
 		logging_callback = &default_logging_callback;
@@ -371,25 +428,69 @@ PAKFIRE_EXPORT int pakfire_execute(Pakfire pakfire, const char* argv[], char* en
 	if (!(flags & PAKFIRE_EXECUTE_ENABLE_NETWORK))
 		args.flags |= CLONE_NEWNET;
 
+	// Setup interactive environment
+	if (flags & PAKFIRE_EXECUTE_INTERACTIVE) {
+		// Set environment
+		r = set_environ(&env, "PS1", "pakfire-chroot \\w> ");
+		if (r)
+			goto ERROR;
+
+		// Copy TERM
+		char* TERM = secure_getenv("TERM");
+		if (TERM) {
+			r = set_environ(&env, "TERM", TERM);
+			if (r)
+				goto ERROR;
+		}
+
+		// Copy LANG
+		char* LANG = secure_getenv("LANG");
+		if (LANG) {
+			r = set_environ(&env, "LANG", LANG);
+			if (r)
+				goto ERROR;
+		}
+
 	// Make some file descriptors for stdout & stderr
-	if (!(flags & PAKFIRE_EXECUTE_INTERACTIVE)) {
+	} else {
 		if (pipe(env.stdout) < 0) {
 			ERROR(pakfire, "Could not create file descriptors for stdout: %s\n",
 				strerror(errno));
-
-			return -errno;
+			r = -1;
+			goto ERROR;
 		}
 
 		if (pipe(env.stderr) < 0) {
 			ERROR(pakfire, "Could not create file descriptors for stderr: %s\n",
 				strerror(errno));
+			r = -1;
+			goto ERROR;
+		}
+	}
 
-			return -errno;
+	// Copy user environment
+	if (envp) {
+		char* key;
+		char* val;
+
+		// Copy environment variables
+		for (unsigned int i = 0; envp[i]; i++) {
+			r = pakfire_string_partition(envp[i], "=", &key, &val);
+			if (r)
+				continue;
+
+			// Set value
+			set_environ(&env, key, val);
+
+			if (key)
+				free(key);
+			if (val)
+				free(val);
 		}
 	}
 
 	// Make cgroup name
-	int r = pakfire_cgroup_random_name(env.cgroup);
+	r = pakfire_cgroup_random_name(env.cgroup);
 	if (r)
 		goto ERROR;
 
@@ -473,6 +574,10 @@ ERROR:
 	if (env.stderr[0])
 		close(env.stderr[0]);
 
+	// Free environment
+	for (unsigned int i = 0; env.envp[i]; i++)
+		free(env.envp[i]);
+
 	return r;
 }
 
diff --git a/src/pakfire/builder.py b/src/pakfire/builder.py
index aff755a7d..20ae0f655 100644
--- a/src/pakfire/builder.py
+++ b/src/pakfire/builder.py
@@ -147,11 +147,7 @@ class BuilderContext(object):
 	@property
 	def environ(self):
 		# Build a minimal environment for executing, but try to inherit TERM and LANG
-		env = {
-			"PS1"  : "pakfire-chroot \w> ",
-			"TERM" : os.environ.get("TERM", "vt100"),
-			"LANG" : os.environ.get("LANG", "en_US.UTF-8"),
-		}
+		env = {}
 
 		# Fake UTS_MACHINE, when we cannot use the personality syscall and
 		# if the host architecture is not equal to the target architecture.