chunk: Provide a fallback chunk_map() if mmap is not available
authorMartin Willi <martin@revosec.ch>
Thu, 21 Nov 2013 13:07:12 +0000 (14:07 +0100)
committerMartin Willi <martin@revosec.ch>
Thu, 23 Jan 2014 14:55:32 +0000 (15:55 +0100)
configure.ac
src/libstrongswan/utils/chunk.c

index ab90571..10f1e19 100644 (file)
@@ -495,7 +495,7 @@ AC_CHECK_FUNC(
 )
 
 AC_CHECK_FUNCS(prctl mallinfo getpass closefrom getpwnam_r getgrnam_r getpwuid_r)
-AC_CHECK_FUNCS(fmemopen funopen)
+AC_CHECK_FUNCS(fmemopen funopen mmap)
 
 AC_CHECK_HEADERS(sys/sockio.h glob.h net/if_tun.h linux/fib_rules.h)
 AC_CHECK_HEADERS(net/pfkeyv2.h netipsec/ipsec.h netinet6/ipsec.h linux/udp.h)
index e308418..5961407 100644 (file)
@@ -18,7 +18,9 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <sys/mman.h>
+#ifdef HAVE_MMAP
+# include <sys/mman.h>
+#endif
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
@@ -317,6 +319,8 @@ typedef struct {
        void *map;
        /* size of map */
        size_t len;
+       /* do we write? */
+       bool wr;
 } mmaped_chunk_t;
 
 /**
@@ -330,6 +334,7 @@ chunk_t *chunk_map(char *path, bool wr)
 
        INIT(chunk,
                .fd = open(path, wr ? O_RDWR : O_RDONLY),
+               .wr = wr,
        );
 
        if (chunk->fd == -1)
@@ -344,6 +349,7 @@ chunk_t *chunk_map(char *path, bool wr)
                errno = tmp;
                return NULL;
        }
+#ifdef HAVE_MMAP
        chunk->len = sb.st_size;
        /* map non-empty files only, as mmap() complains otherwise */
        if (chunk->len)
@@ -360,6 +366,17 @@ chunk_t *chunk_map(char *path, bool wr)
                }
        }
        chunk->public = chunk_create(chunk->map, chunk->len);
+#else /* !HAVE_MMAP */
+       if (!chunk_from_fd(chunk->fd, &chunk->public))
+       {
+               tmp = errno;
+               chunk_unmap(&chunk->public);
+               errno = tmp;
+               return NULL;
+       }
+       chunk->map = chunk->public.ptr;
+       chunk->len = chunk->public.len;
+#endif /* !HAVE_MMAP */
        return &chunk->public;
 }
 
@@ -373,11 +390,39 @@ bool chunk_unmap(chunk_t *public)
        int tmp = 0;
 
        chunk = (mmaped_chunk_t*)public;
+#ifdef HAVE_MMAP
        if (chunk->map && chunk->map != MAP_FAILED)
        {
                ret = munmap(chunk->map, chunk->len) == 0;
                tmp = errno;
        }
+#else /* !HAVE_MMAP */
+       if (chunk->wr)
+       {
+               if (lseek(chunk->fd, 0, SEEK_SET) != -1)
+               {
+                       int len, total = 0;
+
+                       ret = TRUE;
+                       while (total < chunk->len)
+                       {
+                               len = write(chunk->fd, chunk->map + total, chunk->len - total);
+                               if (len <= 0)
+                               {
+                                       ret = FALSE;
+                                       break;
+                               }
+                               total += len;
+                       }
+               }
+               tmp = errno;
+       }
+       else
+       {
+               ret = TRUE;
+       }
+       free(chunk->map);
+#endif /* !HAVE_MMAP */
        close(chunk->fd);
        free(chunk);
        errno = tmp;