Multi-part objects (with header and body separated by an empty line and terminated

[libucw.git] / lib / partmap.c

diff --git a/lib/partmap.c b/lib/partmap.c
index 2947bedffa62ae1e10e3fbbc14cf60349648c503..d3892ff58ffd56816fd4a1ca40d17060e939306d 100644 (file)
--- a/lib/partmap.c
+++ b/lib/partmap.c
@@ -2,6 +2,7 @@
  *     Sherlock Library -- Mapping of File Parts
  *
  *     (c) 2003 Martin Mares <mj@ucw.cz>
+ *     (c) 2003 Robert Spalek <robert@ucw.cz>
  *
  *     This software may be freely distributed and used according to the terms
  *     of the GNU Lesser General Public License.
@@ -16,6 +17,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/mman.h>
+#include <sys/user.h>
 
 struct partmap {
   int fd;
@@ -69,8 +71,12 @@ partmap_map(struct partmap *p, sh_off_t start, uns size)
        munmap(p->start_map, p->end_off - p->start_off);
       uns win = PARTMAP_WINDOW;
       ASSERT(win >= size);
+      sh_off_t end = start + size;
+      start = start/PAGE_SIZE * PAGE_SIZE;
       if (start+win > p->file_size)
        win = p->file_size - start;
+      if (start+win < end)
+       die("cannot mmap, the window is too small");
       p->start_map = sh_mmap(NULL, win, p->writeable ? (PROT_READ | PROT_WRITE) : PROT_READ, MAP_SHARED, p->fd, start);
       if (p->start_map == MAP_FAILED)
        die("mmap failed at position %Ld: %m", (long long)start);