Stop calling setenv() from JNI code

If there's ever an environment that's likely to be multi-threaded, it's
Java. So we really can't use setenv() directly. Instead, add a new
openconnect_set_csd_environ() function and set the environment variables
only after fork().

With a hack to make it look for a $TMPDIR setting because that gets used
*before* forking, for the download location for the script.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

http.c

@@ -714,8 +714,32 @@ static int run_csd_script(struct openconnect_info *vpninfo, char *buf, int bufle
 
 	fname[0] = 0;
 	if (buflen) {
-		char *tmpdir = getenv("TMPDIR");
-		snprintf(fname, 64, "%s/csdXXXXXX", tmpdir ? tmpdir : "/tmp");
+		struct oc_vpn_option *opt;
+		const char *tmpdir = NULL;
+
+		/* If the caller wanted $TMPDIR set for the CSD script, that
+		   means for us too; look through the csd_env for a TMPDIR
+		   override. */
+		for (opt = vpninfo->csd_env; opt; opt = opt->next) {
+			if (!strcmp(opt->option, "TMPDIR")) {
+				tmpdir = opt->value;
+				break;
+			}
+		}
+		if (!opt)
+			tmpdir = getenv("TMPDIR");
+
+		if (!tmpdir && !access("/var/tmp", W_OK))
+			tmpdir = "/var/tmp";
+		if (!tmpdir)
+			tmpdir = "/tmp";
+
+		if (access(tmpdir, W_OK))
+			vpn_progress(vpninfo, PRG_ERR,
+				     _("Temporary directory '%s' is not writable: %s\n"),
+				     tmpdir, strerror(errno));
+
+		snprintf(fname, 64, "%s/csdXXXXXX", tmpdir);
 		fd = mkstemp(fname);
 		if (fd < 0) {
 			int err = -errno;
@@ -803,6 +827,8 @@ static int run_csd_script(struct openconnect_info *vpninfo, char *buf, int bufle
 		if (setenv("CSD_HOSTNAME", vpninfo->hostname, 1))
 			goto out;
 
+		apply_script_env(vpninfo->csd_env);
+
 		execv(csd_argv[0], csd_argv);
 
 out:

jni.c

@@ -804,11 +804,8 @@ JNIEXPORT void JNICALL Java_org_infradead_libopenconnect_LibOpenConnect_setCSDWr
 	    !get_cstring(ctx->jenv, jarg2, &arg2)) {
 		openconnect_setup_csd(ctx->vpninfo, getuid(), 1, arg0);
 
-		if (arg1)
-			setenv("TMPDIR", arg1, 1);
-
-		if (arg2)
-			setenv("PATH", arg2, 1);
+		openconnect_set_csd_environ(ctx->vpninfo, "TMPDIR", arg1);
+		openconnect_set_csd_environ(ctx->vpninfo, "PATH", arg2);
 	}
 
 	release_cstring(ctx->jenv, jarg0, arg0);

libopenconnect.map.in

@@ -61,6 +61,7 @@ OPENCONNECT_4.1 {
 	openconnect_set_system_trust;
 	openconnect_get_dtls_cipher;
 	openconnect_get_cstp_cipher;
+	openconnect_set_csd_environ;
 } OPENCONNECT_4.0;
 
 

library.c

@@ -178,6 +178,7 @@ void openconnect_vpninfo_free(struct openconnect_info *vpninfo)
 		CloseHandle(vpninfo->dtls_event);
 #endif
 	free(vpninfo->peer_addr);
+	free_optlist(vpninfo->csd_env);
 	free_optlist(vpninfo->script_env);
 	free_optlist(vpninfo->cookies);
 	free_optlist(vpninfo->cstp_options);
@@ -215,6 +216,7 @@ void openconnect_vpninfo_free(struct openconnect_info *vpninfo)
 	free(vpninfo->csd_starturl);
 	free(vpninfo->csd_waiturl);
 	free(vpninfo->csd_preurl);
+
 	if (vpninfo->opaque_srvdata)
 		xmlFreeNode(vpninfo->opaque_srvdata);
 	free(vpninfo->profile_url);
@@ -686,3 +688,42 @@ const char *openconnect_get_dtls_cipher(struct openconnect_info *vpninfo)
 	return vpninfo->dtls_cipher;
 #endif
 }
+
+int openconnect_set_csd_environ(struct openconnect_info *vpninfo,
+				const char *name, const char *value)
+{
+	struct oc_vpn_option *p;
+
+	if (!name) {
+		free_optlist(vpninfo->csd_env);
+		vpninfo->csd_env = NULL;
+		return 0;
+	}
+	for (p = vpninfo->csd_env; p; p = p->next) {
+		if (!strcmp(name, p->option)) {
+			char *valdup = strdup(value);
+			if (!valdup)
+				return -ENOMEM;
+			free(p->value);
+			p->value = valdup;
+			return 0;
+		}
+	}
+	p = malloc(sizeof(*p));
+	if (!p)
+		return -ENOMEM;
+	p->option = strdup(name);
+	if (!p->option) {
+		free(p);
+		return -ENOMEM;
+	}
+	p->value = strdup(value);
+	if (!p->value) {
+		free(p->option);
+		free(p);
+		return -ENOMEM;
+	}
+	p->next = vpninfo->csd_env;
+	vpninfo->csd_env = p;
+	return 0;
+}

openconnect-internal.h

@@ -290,6 +290,7 @@ struct openconnect_info {
 	struct oc_vpn_option *dtls_options;
 
 	struct oc_vpn_option *script_env;
+	struct oc_vpn_option *csd_env;
 
 	unsigned pfs;
 #if defined(OPENCONNECT_OPENSSL)
@@ -566,7 +567,7 @@ int script_setenv(struct openconnect_info *vpninfo, const char *opt, const char
 int script_setenv_int(struct openconnect_info *vpninfo, const char *opt, int value);
 void prepare_script_env(struct openconnect_info *vpninfo);
 int script_config_tun(struct openconnect_info *vpninfo, const char *reason);
-int apply_script_env(struct openconnect_info *vpninfo);
+int apply_script_env(struct oc_vpn_option *envs);
 
 /* tun.c / tun-win32.c */
 void os_shutdown_tun(struct openconnect_info *vpninfo);

openconnect.h

@@ -34,7 +34,7 @@
 /*
  * API version 4.1:
  *  - Add openconnect_get_cstp_cipher(), openconnect_get_dtls_cipher(),
- *    openconnect_set_system_trust().
+ *    openconnect_set_system_trust(), openconnect_set_csd_environ().
  *  - Change openconnect_init_ssl() to return int.
  *
  * API version 4.0:
@@ -60,7 +60,7 @@
  *    openconnect_get_ifname(), openconnect_set_reqmtu(),
  *    openconnect_get_ip_info(), openconnect_set_protect_socket_handler(),
  *    openconnect_set_mobile_info(), openconnect_set_xmlpost(),
- *    openconnect_set_stats_handler()
+7 *    openconnect_set_stats_handler()
  *
  * API version 3.0:
  *  - Change oc_form_opt_select->choices to an array of pointers
@@ -283,6 +283,16 @@ typedef enum {
    of the provided strings. */
 
 
+/* Provide environment variables to be set in the CSD trojan environment
+   before spawning it. Some callers may need to set $TMPDIR, $PATH and
+   other such things if not running from a standard UNIX-like environment.
+   To ensure that a variable is unset, pass its name with value==NULL.
+   To clear all settings and allow the CSD trojan to inherit an unmodified
+   environment, call with name==NULL. */
+
+int openconnect_set_csd_environ(struct openconnect_info *vpninfo,
+				const char *name, const char *value);
+
 /* The buffer 'buf' must be at least 41 bytes. It will receive a hex string
    with trailing NUL, representing the SHA1 fingerprint of the certificate. */
 int openconnect_get_cert_sha1(struct openconnect_info *vpninfo,

script.c

@@ -474,11 +474,11 @@ int script_config_tun(struct openconnect_info *vpninfo, const char *reason)
 }
 #else
 /* Must only be run after fork(). */
-int apply_script_env(struct openconnect_info *vpninfo)
+int apply_script_env(struct oc_vpn_option *envs)
 {
-	struct oc_vpn_option *p = vpninfo->script_env;
+	struct oc_vpn_option *p;
 
-	for (p = vpninfo->script_env; p; p = p->next) {
+	for (p = envs; p; p = p->next) {
 		if (p->value)
 			setenv(p->option, p->value, 1);
 		else
@@ -500,7 +500,7 @@ int script_config_tun(struct openconnect_info *vpninfo, const char *reason)
 		/* Child */
 		char *script = openconnect_utf8_to_legacy(vpninfo, vpninfo->vpnc_script);
 
-		apply_script_env(vpninfo);
+		apply_script_env(vpninfo->script_env);
 
 		setenv("reason", reason, 1);
 

tun.c

@@ -475,7 +475,7 @@ int openconnect_setup_tun_script(struct openconnect_info *vpninfo,
 			vpn_perror(vpninfo, _("setpgid"));
 		close(fds[0]);
 		script_setenv_int(vpninfo, "VPNFD", fds[1]);
-		apply_script_env(vpninfo);
+		apply_script_env(vpninfo->script_env);
 		execl("/bin/sh", "/bin/sh", "-c", vpninfo->vpnc_script, NULL);
 		vpn_perror(vpninfo, _("execl"));
 		exit(1);