Refactor kill functions to be independent of services.

[nssm.git] / env.cpp

diff --git a/env.cpp b/env.cpp
index 922c96f..063b60f 100644 (file)
--- a/env.cpp
+++ b/env.cpp
@@ -1,62 +1,125 @@
 #include "nssm.h"
 
-/* Replace NULL with CRLF. Leave NULL NULL as the end marker. */
-int format_environment(TCHAR *env, unsigned long envlen, TCHAR **formatted, unsigned long *newlen) {
-  unsigned long i, j;
-  *newlen = envlen;
+/* Copy an environment block. */
+TCHAR *copy_environment_block(TCHAR *env) {
+  unsigned long len;
 
-  if (! *newlen) {
-    *formatted = 0;
+  if (! env) return 0;
+  for (len = 0; env[len]; len++) while (env[len]) len++;
+  if (! len++) return 0;
+
+  TCHAR *newenv = (TCHAR *) HeapAlloc(GetProcessHeap(), 0, len * sizeof(TCHAR));
+  if (! newenv) {
+    log_event(EVENTLOG_ERROR_TYPE, NSSM_EVENT_OUT_OF_MEMORY, _T("environment"), _T("copy_environment_block()"), 0);
     return 0;
   }
 
-  for (i = 0; i < envlen; i++) if (! env[i] && env[i + 1]) ++*newlen;
+  memmove(newenv, env, len * sizeof(TCHAR));
+  return newenv;
+}
 
-  *formatted = (TCHAR *) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, *newlen * sizeof(TCHAR));
-  if (! *formatted) {
-    *newlen = 0;
-    return 1;
-  }
+/*
+  The environment block starts with variables of the form
+  =C:=C:\Windows\System32 which we ignore.
+*/
+TCHAR *useful_environment(TCHAR *rawenv) {
+  TCHAR *env = rawenv;
 
-  for (i = 0, j = 0; i < envlen; i++) {
-    (*formatted)[j] = env[i];
-    if (! env[i]) {
-      if (env[i + 1]) {
-        (*formatted)[j] = _T('\r');
-        (*formatted)[++j] = _T('\n');
-      }
+  if (env) {
+    while (*env == _T('=')) {
+      for ( ; *env; env++);
+      env++;
     }
-    j++;
   }
 
-  return 0;
+  return env;
 }
 
-/* Strip CR and replace LF with NULL. */
-int unformat_environment(TCHAR *env, unsigned long envlen, TCHAR **unformatted, unsigned long *newlen) {
-  unsigned long i, j;
-  *newlen = 0;
+/* Expand an environment variable.  Must call HeapFree() on the result. */
+TCHAR *expand_environment_string(TCHAR *string) {
+  unsigned long len;
+
+  len = ExpandEnvironmentStrings(string, 0, 0);
+  if (! len) {
+    log_event(EVENTLOG_ERROR_TYPE, NSSM_EVENT_EXPANDENVIRONMENTSTRINGS_FAILED, string, error_string(GetLastError()), 0);
+    return 0;
+  }
+
+  TCHAR *ret = (TCHAR *) HeapAlloc(GetProcessHeap(), 0, len * sizeof(TCHAR));
+  if (! ret) {
+    log_event(EVENTLOG_ERROR_TYPE, NSSM_EVENT_OUT_OF_MEMORY, _T("ExpandEnvironmentStrings()"), _T("expand_environment_string"), 0);
+    return 0;
+  }
 
-  if (! envlen) {
-    *unformatted = 0;
+  if (! ExpandEnvironmentStrings(string, ret, len)) {
+    log_event(EVENTLOG_ERROR_TYPE, NSSM_EVENT_EXPANDENVIRONMENTSTRINGS_FAILED, string, error_string(GetLastError()), 0);
+    HeapFree(GetProcessHeap(), 0, ret);
     return 0;
   }
 
-  for (i = 0; i < envlen; i++) if (env[i] != _T('\r')) ++*newlen;
-  /* Must end with two NULLs. */
-  *newlen += 2;
+  return ret;
+}
 
-  *unformatted = (TCHAR *) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, *newlen * sizeof(TCHAR));
-  if (! *unformatted) return 1;
+/*
+  Set all the environment variables from an environment block in the current
+  environment or remove all the variables in the block from the current
+  environment.
+*/
+static int set_environment_block(TCHAR *env, bool set) {
+  int ret = 0;
 
-  for (i = 0, j = 0; i < envlen; i++) {
-    if (env[i] == _T('\r')) continue;
-    if (env[i] == _T('\n')) (*unformatted)[j] = _T('\0');
-    else (*unformatted)[j] = env[i];
-    j++;
+  TCHAR *s, *t;
+  for (s = env; *s; s++) {
+    for (t = s; *t && *t != _T('='); t++);
+    if (*t == _T('=')) {
+      *t = _T('\0');
+      if (set) {
+        TCHAR *expanded = expand_environment_string(++t);
+        if (expanded) {
+          if (! SetEnvironmentVariable(s, expanded)) ret++;
+          HeapFree(GetProcessHeap(), 0, expanded);
+        }
+        else {
+          if (! SetEnvironmentVariable(s, t)) ret++;
+        }
+      }
+      else {
+        if (! SetEnvironmentVariable(s, NULL)) ret++;
+      }
+      for (t++ ; *t; t++);
+    }
+    s = t;
   }
 
-  return 0;
+  return ret;
+}
+
+int set_environment_block(TCHAR *env) {
+  return set_environment_block(env, true);
+}
+
+static int unset_environment_block(TCHAR *env) {
+  return set_environment_block(env, false);
+}
+
+/* Remove all variables from the process environment. */
+int clear_environment() {
+  TCHAR *rawenv = GetEnvironmentStrings();
+  TCHAR *env = useful_environment(rawenv);
+
+  int ret = unset_environment_block(env);
+
+  if (rawenv) FreeEnvironmentStrings(rawenv);
+
+  return ret;
+}
+
+/* Set the current environment to exactly duplicate an environment block. */
+int duplicate_environment(TCHAR *rawenv) {
+  int ret = clear_environment();
+  TCHAR *env = useful_environment(rawenv);
+  ret += set_environment_block(env);
+  return ret;
 }
 
 /*
@@ -94,3 +157,17 @@ int test_environment(TCHAR *env) {
 
   return 0;
 }
+
+/*
+  Duplicate an environment block returned by GetEnvironmentStrings().
+  Since such a block is by definition readonly, and duplicate_environment()
+  modifies its inputs, this function takes a copy of the input and operates
+  on that.
+*/
+void duplicate_environment_strings(TCHAR *env) {
+  TCHAR *newenv = copy_environment_block(env);
+  if (! newenv) return;
+
+  duplicate_environment(newenv);
+  HeapFree(GetProcessHeap(), 0, newenv);
+}