[PATCH] handle memory allocation failure

[Alexander Kurpiers]

_rtlsdr_alloc_async_buffers() can fail, handle gracefully.
---
src/librtlsdr.c | 52 +++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 43 insertions(+), 9 deletions(-)

diff --git a/src/librtlsdr.c b/src/librtlsdr.c
index 11850e4..5b4ff71 100644
--- a/src/librtlsdr.c
+++ b/src/librtlsdr.c
@@ -1689,6 +1689,8 @@ int rtlsdr_wait_async(rtlsdr_dev_t *dev, rtlsdr_read_async_cb_t cb, void *ctx)
return rtlsdr_read_async(dev, cb, ctx, 0, 0);
}

+static int _rtlsdr_free_async_buffers(rtlsdr_dev_t *dev);
+
static int _rtlsdr_alloc_async_buffers(rtlsdr_dev_t *dev)
{
unsigned int i;
@@ -1697,19 +1699,49 @@ static int _rtlsdr_alloc_async_buffers(rtlsdr_dev_t *dev)
return -1;

if (!dev->xfer) {
- dev->xfer = malloc(dev->xfer_buf_num *
+ dev->xfer = (struct libusb_transfer **)malloc(dev->xfer_buf_num *
sizeof(struct libusb_transfer *));

- for(i = 0; i < dev->xfer_buf_num; ++i)
+ if (dev->xfer == NULL)
+ return -1;
+
+ for(i = 0; i < dev->xfer_buf_num; ++i) {
dev->xfer[i] = libusb_alloc_transfer(0);
+
+ if (dev->xfer[i] == NULL) {
+ while (i>0) {
+ libusb_free_transfer(dev->xfer[--i]);
+ dev->xfer[i] = NULL;
+ }
+ free(dev->xfer);
+ dev->xfer = NULL;
+ return -1;
+ }
+ }
}

if (!dev->xfer_buf) {
- dev->xfer_buf = malloc(dev->xfer_buf_num *
+ dev->xfer_buf = (unsigned char **)malloc(dev->xfer_buf_num *
sizeof(unsigned char *));
+ if (dev->xfer_buf == NULL) {
+ _rtlsdr_free_async_buffers(dev);
+ return -1;
+ }
+
+ for(i = 0; i < dev->xfer_buf_num; ++i) {
+ dev->xfer_buf[i] = (unsigned char*)malloc(dev->xfer_buf_len);

- for(i = 0; i < dev->xfer_buf_num; ++i)
- dev->xfer_buf[i] = malloc(dev->xfer_buf_len);
+ if (dev->xfer_buf[i] == NULL) {
+ while(i>0) {
+ free(dev->xfer_buf[--i]);
+ dev->xfer_buf[i] = NULL;
+ }
+ free(dev->xfer_buf);
+ dev->xfer_buf = NULL;
+ _rtlsdr_free_async_buffers(dev);
+ return -1;
+ }
+ }
}

return 0;
@@ -1761,9 +1793,6 @@ int rtlsdr_read_async(rtlsdr_dev_t *dev, rtlsdr_read_async_cb_t cb, void *ctx,
if (RTLSDR_INACTIVE != dev->async_status)
return -2;

- dev->async_status = RTLSDR_RUNNING;
- dev->async_cancel = 0;
-
dev->cb = cb;
dev->cb_ctx = ctx;

@@ -1777,7 +1806,12 @@ int rtlsdr_read_async(rtlsdr_dev_t *dev, rtlsdr_read_async_cb_t cb, void *ctx,
else
dev->xfer_buf_len = DEFAULT_BUF_LENGTH;

- _rtlsdr_alloc_async_buffers(dev);
+ /* Check the error code. */
+ if(_rtlsdr_alloc_async_buffers(dev) < 0)
+ return -1;
+
+ dev->async_status = RTLSDR_RUNNING;
+ dev->async_cancel = 0;

for(i = 0; i < dev->xfer_buf_num; ++i) {
/* Sleep a little here.