Stop tracking buffer size - it is a constant.

Stop ignoring write errors.
Fix bugs in this line:
rc->buffer_size = read(rc->fd, RC_BUFFER, rc->buffer_size);
(a) should use safe_read()
(b) just ONE short read (e.g. 4 bytes) will make ALL future reads short!

1 files changed, 34 insertions, 25 deletions

diff --git a/archival/libunarchive/decompress_unlzma.c b/archival/libunarchive/decompress_unlzma.c
index c1b0a3118..15a0275b4 100644
--- a/archival/libunarchive/decompress_unlzma.c
+++ b/archival/libunarchive/decompress_unlzma.c
@@ -22,17 +22,23 @@
 typedef struct {
         int fd;
         uint8_t *ptr;
-//      uint8_t *buffer;
+
+/* Was keeping rc on stack in unlzma and separately allocating buffer,
+ * but with "buffer 'attached to' allocated rc" code is smaller: */
+        /* uint8_t *buffer; */
+#define RC_BUFFER ((uint8_t*)(rc+1))
+
         uint8_t *buffer_end;
-        int buffer_size;
+
+/* Had provisions for variable buffer, but we don't need it here */
+        /* int buffer_size; */
+#define RC_BUFFER_SIZE 0x10000
+
         uint32_t code;
         uint32_t range;
         uint32_t bound;
 } rc_t;
 
-//#define RC_BUFFER ((uint8_t*)(void*)(rc+1))
-#define RC_BUFFER ((uint8_t*)(rc+1))
-
 #define RC_TOP_BITS 24
 #define RC_MOVE_BITS 5
 #define RC_MODEL_TOTAL_BITS 11
@@ -41,24 +47,24 @@ typedef struct {
 /* Called twice: once at startup and once in rc_normalize() */
 static void rc_read(rc_t * rc)
 {
-        rc->buffer_size = read(rc->fd, RC_BUFFER, rc->buffer_size);
-        if (rc->buffer_size <= 0)
+        int buffer_size = safe_read(rc->fd, RC_BUFFER, RC_BUFFER_SIZE);
+        if (buffer_size <= 0)
                 bb_error_msg_and_die("unexpected EOF");
         rc->ptr = RC_BUFFER;
-        rc->buffer_end = RC_BUFFER + rc->buffer_size;
+        rc->buffer_end = RC_BUFFER + buffer_size;
 }
 
 /* Called once */
-static rc_t* rc_init(int fd, int buffer_size)
+static rc_t* rc_init(int fd) /*, int buffer_size) */
 {
         int i;
         rc_t* rc;
 
-        rc = xmalloc(sizeof(rc_t) + buffer_size);
+        rc = xmalloc(sizeof(rc_t) + RC_BUFFER_SIZE);
 
         rc->fd = fd;
-        rc->buffer_size = buffer_size;
-        rc->buffer_end = RC_BUFFER + rc->buffer_size;
+        /* rc->buffer_size = buffer_size; */
+        rc->buffer_end = RC_BUFFER + RC_BUFFER_SIZE;
         rc->ptr = rc->buffer_end;
 
         rc->code = 0;
@@ -168,7 +174,7 @@ typedef struct {
 } __attribute__ ((packed)) lzma_header_t;
 
 
-/* #defines will make compiler to compute/optimize each one with each usage.
+/* #defines will force compiler to compute/optimize each one with each usage.
  * Have heart and use enum instead. */
 enum {
         LZMA_BASE_SIZE = 1846,
@@ -244,8 +250,7 @@ unlzma(int src_fd, int dst_fd)
         int state = 0;
         uint32_t rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;
 
-        if (read(src_fd, &header, sizeof(header)) != sizeof(header))
-                bb_error_msg_and_die("can't read header");
+        xread(src_fd, &header, sizeof(header));
 
         if (header.pos >= (9 * 5 * 5))
                 bb_error_msg_and_die("bad header");
@@ -270,7 +275,7 @@ unlzma(int src_fd, int dst_fd)
         for (i = 0; i < num_probs; i++)
                 p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
 
-        rc = rc_init(src_fd, 0x10000);
+        rc = rc_init(src_fd); /*, RC_BUFFER_SIZE); */
 
         while (global_pos + buffer_pos < header.dst_size) {
                 int pos_state = (buffer_pos + global_pos) & pos_state_mask;
@@ -316,8 +321,8 @@ unlzma(int src_fd, int dst_fd)
                         if (buffer_pos == header.dict_size) {
                                 buffer_pos = 0;
                                 global_pos += header.dict_size;
-                                // FIXME: error check
-                                write(dst_fd, buffer, header.dict_size);
+                                if (full_write(dst_fd, buffer, header.dict_size) != header.dict_size)
+                                        goto bad;
                                 USE_DESKTOP(total_written += header.dict_size;)
                         }
                         if (state < 4)
@@ -358,8 +363,8 @@ unlzma(int src_fd, int dst_fd)
                                                 if (buffer_pos == header.dict_size) {
                                                         buffer_pos = 0;
                                                         global_pos += header.dict_size;
-                                                        // FIXME: error check
-                                                        write(dst_fd, buffer, header.dict_size);
+                                                        if (full_write(dst_fd, buffer, header.dict_size) != header.dict_size)
+                                                                goto bad;
                                                         USE_DESKTOP(total_written += header.dict_size;)
                                                 }
                                                 continue;
@@ -471,8 +476,8 @@ unlzma(int src_fd, int dst_fd)
                                 if (buffer_pos == header.dict_size) {
                                         buffer_pos = 0;
                                         global_pos += header.dict_size;
-                                        // FIXME: error check
-                                        write(dst_fd, buffer, header.dict_size);
+                                        if (full_write(dst_fd, buffer, header.dict_size) != header.dict_size)
+                                                goto bad;
                                         USE_DESKTOP(total_written += header.dict_size;)
                                 }
                                 len--;
@@ -480,9 +485,13 @@ unlzma(int src_fd, int dst_fd)
                 }
         }
 
-        // FIXME: error check
-        write(dst_fd, buffer, buffer_pos);
-        USE_DESKTOP(total_written += buffer_pos;)
+
+        if (full_write(dst_fd, buffer, buffer_pos) != buffer_pos) {
+ bad:
+                rc_free(rc);
+                return -1;
+        }
         rc_free(rc);
+        USE_DESKTOP(total_written += buffer_pos;)
         return USE_DESKTOP(total_written) + 0;
 }