X-Git-Url: http://git.iain.cx/?a=blobdiff_plain;f=env.cpp;h=3366fc6573ecc5d4289bd6e5ec9768ef074511ef;hb=62f28c55d444d846579159133dbe091809a2c08b;hp=76c187e34d113744663495afe96c93dd9bab498f;hpb=5380a4a53d9b34d6c56ef3e8a022fcdc184593a3;p=nssm.git

diff --git a/env.cpp b/env.cpp
index 76c187e..3366fc6 100644
--- a/env.cpp
+++ b/env.cpp
@@ -1,141 +1,259 @@
-#include "nssm.h"
-
-/*
-  The environment block starts with variables of the form
-  =C:=C:\Windows\System32 which we ignore.
-*/
-TCHAR *useful_environment(TCHAR *rawenv) {
-  TCHAR *env = rawenv;
-
-  if (env) {
-    while (*env == _T('=')) {
-      for ( ; *env; env++);
-      env++;
-    }
-  }
-
-  return env;
-}
-
-/* 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 (! ExpandEnvironmentStrings(string, ret, len)) {
-    log_event(EVENTLOG_ERROR_TYPE, NSSM_EVENT_EXPANDENVIRONMENTSTRINGS_FAILED, string, error_string(GetLastError()), 0);
-    HeapFree(GetProcessHeap(), 0, ret);
-    return 0;
-  }
-
-  return ret;
-}
-
-/*
-  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;
-
-  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 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;
-}
-
-/*
-  Verify an environment block.
-  Returns:  1 if environment is invalid.
-            0 if environment is OK.
-           -1 on error.
-*/
-int test_environment(TCHAR *env) {
-  TCHAR path[PATH_LENGTH];
-  GetModuleFileName(0, path, _countof(path));
-  STARTUPINFO si;
-  ZeroMemory(&si, sizeof(si));
-  si.cb = sizeof(si);
-  PROCESS_INFORMATION pi;
-  ZeroMemory(&pi, sizeof(pi));
-  unsigned long flags = CREATE_SUSPENDED;
-#ifdef UNICODE
-  flags |= CREATE_UNICODE_ENVIRONMENT;
-#endif
-
-  /*
-    Try to relaunch ourselves but with the candidate environment set.
-    Assuming no solar flare activity, the only reason this would fail is if
-    the environment were invalid.
-  */
-  if (CreateProcess(0, path, 0, 0, 0, flags, env, 0, &si, &pi)) {
-    TerminateProcess(pi.hProcess, 0);
-  }
-  else {
-    unsigned long error = GetLastError();
-    if (error == ERROR_INVALID_PARAMETER) return 1;
-    else return -1;
-  }
-
-  return 0;
-}
+#include "nssm.h"
+
+/*
+  Environment block is of the form:
+
+    KEY1=VALUE1 NULL
+    KEY2=VALUE2 NULL
+    NULL
+
+  A single variable KEY=VALUE has length 15:
+
+    KEY=VALUE (13) NULL (1)
+    NULL (1)
+
+  Environment variable names are case-insensitive!
+*/
+
+/* Find the length in characters of an environment block. */
+size_t environment_length(TCHAR *env) {
+  size_t len = 0;
+
+  TCHAR *s;
+  for (s = env; ; s++) {
+    len++;
+    if (*s == _T('\0')) {
+      if (*(s + 1) == _T('\0')) {
+        len++;
+        break;
+      }
+    }
+  }
+
+  return len;
+}
+
+/* Copy an environment block. */
+TCHAR *copy_environment_block(TCHAR *env) {
+  TCHAR *newenv;
+  if (copy_double_null(env, (unsigned long) environment_length(env), &newenv)) return 0;
+  return newenv;
+}
+
+/*
+  The environment block starts with variables of the form
+  =C:=C:\Windows\System32 which we ignore.
+*/
+TCHAR *useful_environment(TCHAR *rawenv) {
+  TCHAR *env = rawenv;
+
+  if (env) {
+    while (*env == _T('=')) {
+      for ( ; *env; env++);
+      env++;
+    }
+  }
+
+  return env;
+}
+
+/* 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 (! ExpandEnvironmentStrings(string, ret, len)) {
+    log_event(EVENTLOG_ERROR_TYPE, NSSM_EVENT_EXPANDENVIRONMENTSTRINGS_FAILED, string, error_string(GetLastError()), 0);
+    HeapFree(GetProcessHeap(), 0, ret);
+    return 0;
+  }
+
+  return ret;
+}
+
+/*
+  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;
+
+  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 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;
+}
+
+/*
+  Verify an environment block.
+  Returns:  1 if environment is invalid.
+            0 if environment is OK.
+           -1 on error.
+*/
+int test_environment(TCHAR *env) {
+  TCHAR *path = (TCHAR *) nssm_imagepath();
+  STARTUPINFO si;
+  ZeroMemory(&si, sizeof(si));
+  si.cb = sizeof(si);
+  PROCESS_INFORMATION pi;
+  ZeroMemory(&pi, sizeof(pi));
+  unsigned long flags = CREATE_SUSPENDED;
+#ifdef UNICODE
+  flags |= CREATE_UNICODE_ENVIRONMENT;
+#endif
+
+  /*
+    Try to relaunch ourselves but with the candidate environment set.
+    Assuming no solar flare activity, the only reason this would fail is if
+    the environment were invalid.
+  */
+  if (CreateProcess(0, path, 0, 0, 0, flags, env, 0, &si, &pi)) {
+    TerminateProcess(pi.hProcess, 0);
+  }
+  else {
+    unsigned long error = GetLastError();
+    if (error == ERROR_INVALID_PARAMETER) return 1;
+    else return -1;
+  }
+
+  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);
+}
+
+/* Safely get a copy of the current environment. */
+TCHAR *copy_environment() {
+  TCHAR *rawenv = GetEnvironmentStrings();
+  if (! rawenv) return NULL;
+  TCHAR *env = copy_environment_block(rawenv);
+  FreeEnvironmentStrings(rawenv);
+  return env;
+}
+
+/*
+  Create a new block with all the strings of the first block plus a new string.
+  If the key is already present its value will be overwritten in place.
+  If the key is blank or empty the new block will still be allocated and have
+  non-zero length.
+*/
+int append_to_environment_block(TCHAR *env, unsigned long envlen, TCHAR *string, TCHAR **newenv, unsigned long *newlen) {
+  size_t keylen = 0;
+  if (string && string[0]) {
+    for (; string[keylen]; keylen++) {
+      if (string[keylen] == _T('=')) {
+        keylen++;
+        break;
+      }
+    }
+  }
+  return append_to_double_null(env, envlen, newenv, newlen, string, keylen, false);
+}
+
+/*
+  Create a new block with all the strings of the first block minus the given
+  string.
+  If the key is not present the new block will be a copy of the original.
+  If the string is KEY=VALUE the key will only be removed if its value is
+  VALUE.
+  If the string is just KEY the key will unconditionally be removed.
+  If removing the string results in an empty list the new block will still be
+  allocated and have non-zero length.
+*/
+int remove_from_environment_block(TCHAR *env, unsigned long envlen, TCHAR *string, TCHAR **newenv, unsigned long *newlen) {
+  if (! string || ! string[0] || string[0] == _T('=')) return 1;
+
+  TCHAR *key = 0;
+  size_t len = _tcslen(string);
+  size_t i;
+  for (i = 0; i < len; i++) if (string[i] == _T('=')) break;
+
+  /* Rewrite KEY to KEY= but leave KEY=VALUE alone. */
+  size_t keylen = len;
+  if (i == len) keylen++;
+
+  key = (TCHAR *) HeapAlloc(GetProcessHeap(), 0, (keylen + 1) * sizeof(TCHAR));
+  if (! key) {
+    log_event(EVENTLOG_ERROR_TYPE, NSSM_EVENT_OUT_OF_MEMORY, _T("key"), _T("remove_from_environment_block()"), 0);
+    return 2;
+  }
+  memmove(key, string, len * sizeof(TCHAR));
+  if (keylen > len) key[keylen - 1] = _T('=');
+  key[keylen] = _T('\0');
+
+  int ret = remove_from_double_null(env, envlen, newenv, newlen, key, keylen, false);
+  HeapFree(GetProcessHeap(), 0, key);
+
+  return ret;
+}