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[tor-commits] [tor/master] Rewrite managed proxy environment setup code
commit bf1ce3f53d67c4c0e71f79a108e1eaa04fbfb713
Author: Robert Ransom <rransom.8774@xxxxxxxxx>
Date: Mon Feb 13 00:46:18 2012 -0800
Rewrite managed proxy environment setup code
Now, the environment setup is entirely OS-independent, as well as less
hacky and brittle.
---
changes/bug5105 | 11 +++
src/or/transports.c | 234 ++++++++++++++-------------------------------------
2 files changed, 73 insertions(+), 172 deletions(-)
diff --git a/changes/bug5105 b/changes/bug5105
new file mode 100644
index 0000000..6a923d9
--- /dev/null
+++ b/changes/bug5105
@@ -0,0 +1,11 @@
+ o Minor bugfixes:
+
+ - Ensure that variables set in Tor's environment cannot override
+ environment variables which Tor tries to pass to a managed
+ pluggable-transport proxy. Previously, Tor would pass every
+ variable in its environment to managed proxies along with the
+ new ones, in such a way that on many operating systems, the
+ inherited environment variables would override those which Tor
+ tried to explicitly set. Bugfix on 0.2.3.12-alpha for most
+ Unixoid systems; bugfix on 0.2.3.9-alpha for Windows.
+
diff --git a/src/or/transports.c b/src/or/transports.c
index d279d7a..b3c8382 100644
--- a/src/or/transports.c
+++ b/src/or/transports.c
@@ -91,13 +91,8 @@
#include "util.h"
#include "router.h"
-#ifdef _WIN32
-static void set_managed_proxy_environment(LPVOID *envp,
- const managed_proxy_t *mp);
-#else
-static void set_managed_proxy_environment(char ***envp,
- const managed_proxy_t *mp);
-#endif
+static process_environment_t *
+create_managed_proxy_environment(const managed_proxy_t *mp);
static INLINE int proxy_configuration_finished(const managed_proxy_t *mp);
@@ -287,35 +282,23 @@ launch_managed_proxy(managed_proxy_t *mp)
{
int retval;
-#ifdef _WIN32
-
- LPVOID envp=NULL;
-
- set_managed_proxy_environment(&envp, mp);
- tor_assert(envp);
+ process_environment_t *env = create_managed_proxy_environment(mp);
+#ifdef _WIN32
/* Passing NULL as lpApplicationName makes Windows search for the .exe */
- retval = tor_spawn_background(NULL, (const char **)mp->argv, envp,
+ retval = tor_spawn_background(NULL,
+ (const char **)mp->argv,
+ env->windows_environment_block,
&mp->process_handle);
-
- tor_free(envp);
-
#else
-
- char **envp=NULL;
-
- /* prepare the environment variables for the managed proxy */
- set_managed_proxy_environment(&envp, mp);
- tor_assert(envp);
-
- retval = tor_spawn_background(mp->argv[0], (const char **)mp->argv,
- (const char **)envp, &mp->process_handle);
-
- /* free the memory allocated by set_managed_proxy_environment(). */
- free_execve_args(envp);
-
+ retval = tor_spawn_background(mp->argv[0],
+ (const char **)mp->argv,
+ env->unixoid_environment_block,
+ &mp->process_handle);
#endif
+ process_environment_free(env);
+
if (retval == PROCESS_STATUS_ERROR) {
log_warn(LD_GENERAL, "Managed proxy at '%s' failed at launch.",
mp->argv[0]);
@@ -971,171 +954,78 @@ get_bindaddr_for_server_proxy(const managed_proxy_t *mp)
return bindaddr_result;
}
-#ifdef _WIN32
-
-/** Prepare the environment <b>envp</b> of managed proxy <b>mp</b>.
- * <b>envp</b> is allocated on the heap and should be freed by the
- * caller after its use. */
-static void
-set_managed_proxy_environment(LPVOID *envp, const managed_proxy_t *mp)
+/** Return a newly allocated process_environment_t * for <b>mp</b>'s
+ * process. */
+static process_environment_t *
+create_managed_proxy_environment(const managed_proxy_t *mp)
{
const or_options_t *options = get_options();
- char *tmp=NULL;
- char *state_tmp=NULL;
- char *state_env=NULL;
- char *transports_to_launch=NULL;
- char *transports_env=NULL;
- char *bindaddr_tmp=NULL;
- char *bindaddr_env=NULL;
- char *orport_env=NULL;
-
- char version_env[31]; /* XXX temp */
- char extended_env[43]; /* XXX temp */
-
- int env_size = 0;
-
- /* A smartlist carrying all the env. variables that the managed
- proxy should inherit. */
+ /* Environment variables to be added to or set in mp's environment.
+ * These are heap-allocated and are freed before this function
+ * returns. */
smartlist_t *envs = smartlist_new();
- /* Copy the whole environment of the Tor process.
- It should also copy PATH and HOME of the Tor process.*/
- char **environ_tmp = environ;
- while (*environ_tmp)
- smartlist_add(envs, *environ_tmp++);
+ /* The final environment to be passed to mp. Inherited variables are
+ * statically allocated; new ones are heap-allocated. */
+ smartlist_t *merged_env_vars = get_current_process_environment_variables();
- /* Create the TOR_PT_* environment variables. */
- state_tmp = get_datadir_fname("pt_state/"); /* XXX temp */
- tor_asprintf(&state_env, "TOR_PT_STATE_LOCATION=%s", state_tmp);
+ process_environment_t *env;
- strcpy(version_env, "TOR_PT_MANAGED_TRANSPORT_VER=1");
-
- transports_to_launch =
- smartlist_join_strings(mp->transports_to_launch, ",", 0, NULL);
-
- tor_asprintf(&transports_env,
- mp->is_server ?
- "TOR_PT_SERVER_TRANSPORTS=%s" : "TOR_PT_CLIENT_TRANSPORTS=%s",
- transports_to_launch);
-
- smartlist_add(envs, state_env);
- smartlist_add(envs, version_env);
- smartlist_add(envs, transports_env);
+ {
+ char *state_tmp = get_datadir_fname("pt_state/"); /* XXX temp */
+ smartlist_add_asprintf(envs, "TOR_PT_STATE_LOCATION=%s", state_tmp);
+ tor_free(state_tmp);
+ }
- if (mp->is_server) {
- tor_asprintf(&orport_env, "TOR_PT_ORPORT=127.0.0.1:%s",
- options->ORPort->value);
+ smartlist_add(envs, tor_strdup("TOR_PT_MANAGED_TRANSPORT_VER=1"));
- bindaddr_tmp = get_bindaddr_for_server_proxy(mp);
- tor_asprintf(&bindaddr_env, "TOR_PT_SERVER_BINDADDR=%s", bindaddr_tmp);
+ {
+ char *transports_to_launch =
+ smartlist_join_strings(mp->transports_to_launch, ",", 0, NULL);
- strlcpy(extended_env, "TOR_PT_EXTENDED_SERVER_PORT=",
- sizeof(extended_env));
+ smartlist_add_asprintf(envs,
+ mp->is_server ?
+ "TOR_PT_SERVER_TRANSPORTS=%s" :
+ "TOR_PT_CLIENT_TRANSPORTS=%s",
+ transports_to_launch);
- smartlist_add(envs, orport_env);
- smartlist_add(envs, extended_env);
- smartlist_add(envs, bindaddr_env);
+ tor_free(transports_to_launch);
}
- /* It seems like some versions of Windows need a sorted lpEnvironment
- block. */
- smartlist_sort_strings(envs);
-
- /* An environment block consists of a null-terminated block of
- null-terminated strings: */
-
- /* Calculate the block's size. */
- SMARTLIST_FOREACH(envs, const char *, s,
- env_size += strlen(s) + 1);
- env_size += 1; /* space for last NUL */
-
- *envp = tor_malloc(env_size);
- tmp = *envp;
-
- /* Create the block. */
- SMARTLIST_FOREACH_BEGIN(envs, const char *, s) {
- memcpy(tmp, s, strlen(s)); /* copy the env. variable string */
- tmp += strlen(s);
- memset(tmp, '\0', 1); /* append NUL at the end of the string */
- tmp += 1;
- } SMARTLIST_FOREACH_END(s);
- memset(tmp, '\0', 1); /* last NUL */
-
- /* Finally, free the whole mess. */
- tor_free(state_tmp);
- tor_free(state_env);
- tor_free(transports_to_launch);
- tor_free(transports_env);
- tor_free(bindaddr_tmp);
- tor_free(bindaddr_env);
- tor_free(orport_env);
-
- smartlist_free(envs);
-}
-
-#else /* _WIN32 */
+ if (mp->is_server) {
+ smartlist_add_asprintf(envs, "TOR_PT_ORPORT=127.0.0.1:%s",
+ options->ORPort->value);
-extern char **environ;
+ {
+ char *bindaddr_tmp = get_bindaddr_for_server_proxy(mp);
+ smartlist_add_asprintf(envs, "TOR_PT_SERVER_BINDADDR=%s", bindaddr_tmp);
+ tor_free(bindaddr_tmp);
+ }
-/** Prepare the environment <b>envp</b> of managed proxy <b>mp</b>.
- * <b>envp</b> is allocated on the heap and should be freed by the
- * caller after its use. */
-static void
-set_managed_proxy_environment(char ***envp, const managed_proxy_t *mp)
-{
- const or_options_t *options = get_options();
- char **tmp=NULL;
- char *state_loc=NULL;
- char *transports_to_launch=NULL;
- char *bindaddr=NULL;
- int environ_size=0;
- char **environ_tmp = environ;
-
- int n_envs = mp->is_server ? ENVIRON_SIZE_SERVER : ENVIRON_SIZE_CLIENT;
-
- while (*environ_tmp) {
- environ_size++;
- environ_tmp++;
+ /* XXX023 Remove the '=' here once versions of obfsproxy which
+ * assert that this env var exists are sufficiently dead.
+ *
+ * (If we remove this line entirely, some joker will stick this
+ * variable in Tor's environment and crash PTs that try to parse
+ * it even when not run in server mode.) */
+ smartlist_add(envs, tor_strdup("TOR_PT_EXTENDED_SERVER_PORT="));
}
- environ_tmp = environ;
- /* allocate enough space for our env. vars and a NULL pointer */
- *envp = tor_malloc(sizeof(char*)*(environ_size+n_envs+1));
- tmp = *envp;
+ SMARTLIST_FOREACH_BEGIN(envs, const char *, env_var) {
+ set_environment_variable_in_smartlist(merged_env_vars, env_var, NULL, 0);
+ } SMARTLIST_FOREACH_END(env_var);
- state_loc = get_datadir_fname("pt_state/"); /* XXX temp */
- transports_to_launch =
- smartlist_join_strings(mp->transports_to_launch, ",", 0, NULL);
+ env = process_environment_make(merged_env_vars);
- while (*environ_tmp) {
- *tmp = tor_strdup(*environ_tmp);
- tmp++, environ_tmp++;
- }
+ smartlist_free(merged_env_vars);
- tor_asprintf(tmp++, "TOR_PT_STATE_LOCATION=%s", state_loc);
- tor_asprintf(tmp++, "TOR_PT_MANAGED_TRANSPORT_VER=1"); /* temp */
- if (mp->is_server) {
- bindaddr = get_bindaddr_for_server_proxy(mp);
-
- /* XXX temp */
- tor_asprintf(tmp++, "TOR_PT_ORPORT=127.0.0.1:%d",
- router_get_advertised_or_port(options));
- tor_asprintf(tmp++, "TOR_PT_SERVER_BINDADDR=%s", bindaddr);
- tor_asprintf(tmp++, "TOR_PT_SERVER_TRANSPORTS=%s", transports_to_launch);
- tor_asprintf(tmp++, "TOR_PT_EXTENDED_SERVER_PORT=");
- } else {
- tor_asprintf(tmp++, "TOR_PT_CLIENT_TRANSPORTS=%s", transports_to_launch);
- }
- *tmp = NULL;
+ SMARTLIST_FOREACH(envs, void *, x, tor_free(x));
+ smartlist_free(envs);
- tor_free(state_loc);
- tor_free(transports_to_launch);
- tor_free(bindaddr);
+ return env;
}
-#endif /* _WIN32 */
-
/** Create and return a new managed proxy for <b>transport</b> using
* <b>proxy_argv</b>. If <b>is_server</b> is true, it's a server
* managed proxy. */
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