udhcpc: fix a problem with binary-encoded options #2

[oweals/busybox.git] / modutils / modutils.c

diff --git a/modutils/modutils.c b/modutils/modutils.c
index 969926db98c83744aff1f1751af2ebdf4a1089fe..6187ca72fd3835fa28a18158205a5856913cfd75 100644 (file)
--- a/modutils/modutils.c
+++ b/modutils/modutils.c
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2008 by Timo Teras <timo.teras@iki.fi>
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 #include "modutils.h"
 
@@ -62,7 +62,7 @@ char* FAST_FUNC filename2modname(const char *filename, char *modname)
        return modname;
 }
 
-char * FAST_FUNC parse_cmdline_module_options(char **argv)
+char* FAST_FUNC parse_cmdline_module_options(char **argv, int quote_spaces)
 {
        char *options;
        int optlen;
@@ -70,13 +70,68 @@ char * FAST_FUNC parse_cmdline_module_options(char **argv)
        options = xzalloc(1);
        optlen = 0;
        while (*++argv) {
-               options = xrealloc(options, optlen + 2 + strlen(*argv) + 2);
-               /* Spaces handled by "" pairs, but no way of escaping quotes */
-               optlen += sprintf(options + optlen, (strchr(*argv, ' ') ? "\"%s\" " : "%s "), *argv);
+               const char *fmt;
+               const char *var;
+               const char *val;
+
+               var = *argv;
+               options = xrealloc(options, optlen + 2 + strlen(var) + 2);
+               fmt = "%.*s%s ";
+               val = strchrnul(var, '=');
+               if (quote_spaces) {
+                       /*
+                        * modprobe (module-init-tools version 3.11.1) compat:
+                        * quote only value:
+                        * var="val with spaces", not "var=val with spaces"
+                        * (note: var *name* is not checked for spaces!)
+                        */
+                       if (*val) { /* has var=val format. skip '=' */
+                               val++;
+                               if (strchr(val, ' '))
+                                       fmt = "%.*s\"%s\" ";
+                       }
+               }
+               optlen += sprintf(options + optlen, fmt, (int)(val - var), var, val);
        }
+       /* Remove trailing space. Disabled */
+       /* if (optlen != 0) options[optlen-1] = '\0'; */
        return options;
 }
 
+#if ENABLE_FEATURE_INSMOD_TRY_MMAP
+void* FAST_FUNC try_to_mmap_module(const char *filename, size_t *image_size_p)
+{
+       /* We have user reports of failure to load 3MB module
+        * on a 16MB RAM machine. Apparently even a transient
+        * memory spike to 6MB during module load
+        * is too big for that system. */
+       void *image;
+       struct stat st;
+       int fd;
+
+       fd = xopen(filename, O_RDONLY);
+       fstat(fd, &st);
+       image = NULL;
+       /* st.st_size is off_t, we can't just pass it to mmap */
+       if (st.st_size <= *image_size_p) {
+               size_t image_size = st.st_size;
+               image = mmap(NULL, image_size, PROT_READ, MAP_PRIVATE, fd, 0);
+               if (image == MAP_FAILED) {
+                       image = NULL;
+               } else if (*(uint32_t*)image != SWAP_BE32(0x7f454C46)) {
+                       /* No ELF signature. Compressed module? */
+                       munmap(image, image_size);
+                       image = NULL;
+               } else {
+                       /* Success. Report the size */
+                       *image_size_p = image_size;
+               }
+       }
+       close(fd);
+       return image;
+}
+#endif
+
 /* Return:
  * 0 on success,
  * -errno on open/read error,
@@ -84,9 +139,10 @@ char * FAST_FUNC parse_cmdline_module_options(char **argv)
  */
 int FAST_FUNC bb_init_module(const char *filename, const char *options)
 {
-       size_t len;
+       size_t image_size;
        char *image;
        int rc;
+       bool mmaped;
 
        if (!options)
                options = "";
@@ -97,17 +153,25 @@ int FAST_FUNC bb_init_module(const char *filename, const char *options)
                return bb_init_module_24(filename, options);
 #endif
 
-       /* Use the 2.6 way */
-       len = INT_MAX - 4095;
-       errno = ENOMEM; /* may be changed by e.g. open errors below */
-       image = xmalloc_open_zipped_read_close(filename, &len);
-       if (!image)
-               return -errno;
+       image_size = INT_MAX - 4095;
+       mmaped = 0;
+       image = try_to_mmap_module(filename, &image_size);
+       if (image) {
+               mmaped = 1;
+       } else {
+               errno = ENOMEM; /* may be changed by e.g. open errors below */
+               image = xmalloc_open_zipped_read_close(filename, &image_size);
+               if (!image)
+                       return -errno;
+       }
 
        errno = 0;
-       init_module(image, len, options);
+       init_module(image, image_size, options);
        rc = errno;
-       free(image);
+       if (mmaped)
+               munmap(image, image_size);
+       else
+               free(image);
        return rc;
 }