TOMOYO: Add environment variable name restriction support.
[linux-3.10.git] / security / tomoyo / audit.c
index b33a20a..5dbb1f7 100644 (file)
 /*
  * security/tomoyo/audit.c
  *
- * Pathname restriction functions.
- *
- * Copyright (C) 2005-2010  NTT DATA CORPORATION
+ * Copyright (C) 2005-2011  NTT DATA CORPORATION
  */
 
 #include "common.h"
 #include <linux/slab.h>
 
 /**
+ * tomoyo_print_bprm - Print "struct linux_binprm" for auditing.
+ *
+ * @bprm: Pointer to "struct linux_binprm".
+ * @dump: Pointer to "struct tomoyo_page_dump".
+ *
+ * Returns the contents of @bprm on success, NULL otherwise.
+ *
+ * This function uses kzalloc(), so caller must kfree() if this function
+ * didn't return NULL.
+ */
+static char *tomoyo_print_bprm(struct linux_binprm *bprm,
+                              struct tomoyo_page_dump *dump)
+{
+       static const int tomoyo_buffer_len = 4096 * 2;
+       char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS);
+       char *cp;
+       char *last_start;
+       int len;
+       unsigned long pos = bprm->p;
+       int offset = pos % PAGE_SIZE;
+       int argv_count = bprm->argc;
+       int envp_count = bprm->envc;
+       bool truncated = false;
+       if (!buffer)
+               return NULL;
+       len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ ");
+       cp = buffer + len;
+       if (!argv_count) {
+               memmove(cp, "} envp[]={ ", 11);
+               cp += 11;
+       }
+       last_start = cp;
+       while (argv_count || envp_count) {
+               if (!tomoyo_dump_page(bprm, pos, dump))
+                       goto out;
+               pos += PAGE_SIZE - offset;
+               /* Read. */
+               while (offset < PAGE_SIZE) {
+                       const char *kaddr = dump->data;
+                       const unsigned char c = kaddr[offset++];
+                       if (cp == last_start)
+                               *cp++ = '"';
+                       if (cp >= buffer + tomoyo_buffer_len - 32) {
+                               /* Reserve some room for "..." string. */
+                               truncated = true;
+                       } else if (c == '\\') {
+                               *cp++ = '\\';
+                               *cp++ = '\\';
+                       } else if (c > ' ' && c < 127) {
+                               *cp++ = c;
+                       } else if (!c) {
+                               *cp++ = '"';
+                               *cp++ = ' ';
+                               last_start = cp;
+                       } else {
+                               *cp++ = '\\';
+                               *cp++ = (c >> 6) + '0';
+                               *cp++ = ((c >> 3) & 7) + '0';
+                               *cp++ = (c & 7) + '0';
+                       }
+                       if (c)
+                               continue;
+                       if (argv_count) {
+                               if (--argv_count == 0) {
+                                       if (truncated) {
+                                               cp = last_start;
+                                               memmove(cp, "... ", 4);
+                                               cp += 4;
+                                       }
+                                       memmove(cp, "} envp[]={ ", 11);
+                                       cp += 11;
+                                       last_start = cp;
+                                       truncated = false;
+                               }
+                       } else if (envp_count) {
+                               if (--envp_count == 0) {
+                                       if (truncated) {
+                                               cp = last_start;
+                                               memmove(cp, "... ", 4);
+                                               cp += 4;
+                                       }
+                               }
+                       }
+                       if (!argv_count && !envp_count)
+                               break;
+               }
+               offset = 0;
+       }
+       *cp++ = '}';
+       *cp = '\0';
+       return buffer;
+out:
+       snprintf(buffer, tomoyo_buffer_len - 1,
+                "argv[]={ ... } envp[]= { ... }");
+       return buffer;
+}
+
+/**
  * tomoyo_filetype - Get string representation of file type.
  *
  * @mode: Mode value for stat().
@@ -139,6 +235,7 @@ char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
                      va_list args)
 {
        char *buf = NULL;
+       char *bprm_info = NULL;
        const char *header = NULL;
        char *realpath = NULL;
        const char *symlink = NULL;
@@ -152,10 +249,11 @@ char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
        if (r->ee) {
                struct file *file = r->ee->bprm->file;
                realpath = tomoyo_realpath_from_path(&file->f_path);
-               if (!realpath)
+               bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump);
+               if (!realpath || !bprm_info)
                        goto out;
-               /* +80 is for " exec={ realpath=\"%s\" }" */
-               len += strlen(realpath) + 80;
+               /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */
+               len += strlen(realpath) + 80 + strlen(bprm_info);
        } else if (r->obj && r->obj->symlink_target) {
                symlink = r->obj->symlink_target->name;
                /* +18 is for " symlink.target=\"%s\"" */
@@ -168,8 +266,10 @@ char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
        len--;
        pos = snprintf(buf, len, "%s", header);
        if (realpath) {
+               struct linux_binprm *bprm = r->ee->bprm;
                pos += snprintf(buf + pos, len - pos,
-                               " exec={ realpath=\"%s\" }", realpath);
+                               " exec={ realpath=\"%s\" argc=%d envc=%d %s }",
+                               realpath, bprm->argc, bprm->envc, bprm_info);
        } else if (symlink)
                pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
                                symlink);
@@ -177,6 +277,7 @@ char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
        vsnprintf(buf + pos, len - pos, fmt, args);
 out:
        kfree(realpath);
+       kfree(bprm_info);
        kfree(header);
        return buf;
 }