change proc_args to use the PEB

src/os/win32/peb.c

@@ -34,12 +34,12 @@ static int sigar_peb_get(sigar_t *sigar, HANDLE proc, DWORD *base)
     return SIGAR_OK;
 }
 
-//point scratch to PATH env var
-#define PEB_PATH(scratch, base) \
+//point scratch to env block
+#define PEB_FIRST(scratch, base) \
     scratch = sigar->peb + ((DWORD)START_ADDRESS - base)
 
-//point scratch to EXE (assumes PEB_PATH)
-#define PEB_EXE(scratch) \
+//point scratch to next string (assumes PEB_FIRST)
+#define PEB_NEXT(scratch) \
     scratch = scratch + (wcslen((LPWSTR)scratch) + 1) * sizeof(WCHAR)
 
 int sigar_proc_exe_name_get(sigar_t *sigar, HANDLE proc, char *name)
@@ -54,9 +54,9 @@ int sigar_proc_exe_name_get(sigar_t *sigar, HANDLE proc, char *name)
     }
 
     //skip env PATH
-    PEB_PATH(scratch, base);
+    PEB_FIRST(scratch, base);
 
-    PEB_EXE(scratch);
+    PEB_NEXT(scratch);
 
     //seems common, reason unknown.
     if (*scratch == '\0') {
@@ -70,3 +70,36 @@ int sigar_proc_exe_name_get(sigar_t *sigar, HANDLE proc, char *name)
 
     return SIGAR_OK;
 }
+
+int sigar_proc_cmdline_get(sigar_t *sigar, HANDLE proc, char *cmdline)
+{
+    int status;
+    LPBYTE scratch;
+    DWORD base;
+    WCHAR buf[MAX_PATH];
+
+    if ((status = sigar_peb_get(sigar, proc, &base)) != SIGAR_OK) {
+        return status;
+    }
+
+    //skip env block
+    PEB_FIRST(scratch, base);
+
+    PEB_NEXT(scratch);
+    //seems common, reason unknown.
+    if (*scratch == '\0') {
+        scratch += sizeof(WCHAR);
+    }
+
+    PEB_NEXT(scratch);
+    if (*scratch == '\0') {
+        scratch += sizeof(WCHAR);
+    }
+
+    wcsncpy(buf, (LPWSTR)scratch, MAX_PATH);
+    buf[MAX_PATH-1] = L'\0';
+
+    SIGAR_W2A(buf, cmdline, MAX_PATH);
+
+    return SIGAR_OK;
+}

src/os/win32/sigar_os.h

@@ -121,6 +121,8 @@ int sigar_wsa_init(sigar_t *sigar);
 
 int sigar_proc_exe_name_get(sigar_t *sigar, HANDLE proc, char *name);
 
+int sigar_proc_cmdline_get(sigar_t *sigar, HANDLE proc, char *cmdline);
+
 unsigned int sigar_cpu_count(sigar_t *sigar);
 
 int sigar_cpu_info_get(sigar_t *sigar, sigar_cpu_info_t *info);

src/os/win32/win32_sigar.c

@@ -804,6 +804,10 @@ static char *getarg(char **line)
     return res;
 }
 
+#if 0
+/* this was the first shot, works but injects a remote thread
+ * in the process.  probably best to avoid that.
+ */
 /*
  * this is ugly, but there is no alternative.
  * we spawn a remote thread within the process
@@ -901,6 +905,40 @@ static int sigar_remote_proc_args_get(sigar_t *sigar, sigar_pid_t pid,
     CloseHandle(proc);
     return SIGAR_OK;
 }
+#else
+/* second shot, using the PEB.
+ * read-only, minimum access privs and in general seems to work
+ * better than the method above.  lets roll...
+ */
+static int sigar_remote_proc_args_get(sigar_t *sigar, sigar_pid_t pid,
+                                      sigar_proc_args_t *procargs)
+{
+    int status;
+    char cmdline[MAX_PATH], *ptr = cmdline, *arg;
+    HANDLE proc = open_process(pid);
+
+    if (!proc) {
+        return GetLastError();
+    }
+    
+    status = sigar_proc_cmdline_get(sigar, proc, cmdline);
+
+    CloseHandle(proc);
+
+    if (status != SIGAR_OK) {
+        return status;
+    }
+
+    sigar_proc_args_create(procargs);
+
+    while (*ptr && (arg = getarg(&ptr))) {
+        SIGAR_PROC_ARGS_GROW(procargs);
+        procargs->data[procargs->number++] = strdup(arg);
+    }
+
+    return SIGAR_OK;
+}
+#endif
 
 static int sigar_local_proc_args_get(sigar_t *sigar, sigar_pid_t pid,
                                      sigar_proc_args_t *procargs)