Fix edge case in pbuf_take_at()

Writes to offsets pointing to the start of a pbuf in the chain
did nothing and just returned ERR_OK.

Added unit tests to verify the fix, and also
that pbuf_get_at()/pbuf_put_at() handles this case.
This commit is contained in:
Erik Ekman 2015-07-01 12:55:39 +02:00 committed by sg
parent 22d2af2a29
commit 145efb1a33
2 changed files with 88 additions and 8 deletions

View File

@ -1125,13 +1125,11 @@ pbuf_take_at(struct pbuf *buf, const void *dataptr, u16_t len, u16_t offset)
if ((q != NULL) && (q->tot_len >= target_offset + len)) {
u16_t remaining_len = len;
const u8_t* src_ptr = (const u8_t*)dataptr;
if (target_offset > 0) {
/* copy the part that goes into the first pbuf */
u16_t first_copy_len = LWIP_MIN(q->len - target_offset, len);
MEMCPY(((u8_t*)q->payload) + target_offset, dataptr, first_copy_len);
remaining_len -= first_copy_len;
src_ptr += first_copy_len;
}
/* copy the part that goes into the first pbuf */
u16_t first_copy_len = LWIP_MIN(q->len - target_offset, len);
MEMCPY(((u8_t*)q->payload) + target_offset, dataptr, first_copy_len);
remaining_len -= first_copy_len;
src_ptr += first_copy_len;
if (remaining_len > 0) {
return pbuf_take(q->next, src_ptr, remaining_len);
}

View File

@ -139,6 +139,86 @@ START_TEST(test_pbuf_queueing_bigger_than_64k)
}
END_TEST
/* Test for bug that writing with pbuf_take_at() did nothing
* and returned ERR_OK when writing at beginning of a pbuf
* in the chain.
*/
START_TEST(test_pbuf_take_at_edge)
{
err_t res;
u8_t *out;
int i;
u8_t testdata[] = { 0x01, 0x08, 0x82, 0x02 };
struct pbuf *p = pbuf_alloc(PBUF_RAW, 1024, PBUF_POOL);
struct pbuf *q = p->next;
/* alloc big enough to get a chain of pbufs */
fail_if(p->tot_len == p->len);
memset(p->payload, 0, p->len);
memset(q->payload, 0, q->len);
/* copy data to the beginning of first pbuf */
res = pbuf_take_at(p, &testdata, sizeof(testdata), 0);
fail_unless(res == ERR_OK);
out = p->payload;
for (i = 0; i < sizeof(testdata); i++) {
fail_unless(out[i] == testdata[i],
"Bad data at pos %d, was %02X, expected %02X", i, out[i], testdata[i]);
}
/* copy data to the just before end of first pbuf */
res = pbuf_take_at(p, &testdata, sizeof(testdata), p->len - 1);
fail_unless(res == ERR_OK);
out = p->payload;
fail_unless(out[p->len - 1] == testdata[0],
"Bad data at pos %d, was %02X, expected %02X", p->len - 1, out[p->len - 1], testdata[0]);
out = q->payload;
for (i = 1; i < sizeof(testdata); i++) {
fail_unless(out[i-1] == testdata[i],
"Bad data at pos %d, was %02X, expected %02X", p->len - 1 + i, out[i-1], testdata[i]);
}
/* copy data to the beginning of second pbuf */
res = pbuf_take_at(p, &testdata, sizeof(testdata), p->len);
fail_unless(res == ERR_OK);
out = p->payload;
for (i = 0; i < sizeof(testdata); i++) {
fail_unless(out[i] == testdata[i],
"Bad data at pos %d, was %02X, expected %02X", p->len+i, out[i], testdata[i]);
}
}
END_TEST
/* Verify pbuf_put_at()/pbuf_get_at() when using
* offsets equal to beginning of new pbuf in chain
*/
START_TEST(test_pbuf_get_put_at_edge)
{
u8_t *out;
u8_t testdata = 0x01;
u8_t getdata;
struct pbuf *p = pbuf_alloc(PBUF_RAW, 1024, PBUF_POOL);
struct pbuf *q = p->next;
/* alloc big enough to get a chain of pbufs */
fail_if(p->tot_len == p->len);
memset(p->payload, 0, p->len);
memset(q->payload, 0, q->len);
/* put byte at the beginning of second pbuf */
pbuf_put_at(p, p->len, testdata);
out = q->payload;
fail_unless(*out == testdata,
"Bad data at pos %d, was %02X, expected %02X", p->len, *out, testdata);
getdata = pbuf_get_at(p, p->len);
fail_unless(*out == getdata,
"pbuf_get_at() returned bad data at pos %d, was %02X, expected %02X", p->len, getdata, *out);
}
END_TEST
/** Create the suite including all tests for this module */
Suite *
pbuf_suite(void)
@ -146,7 +226,9 @@ pbuf_suite(void)
testfunc tests[] = {
TESTFUNC(test_pbuf_copy_zero_pbuf),
TESTFUNC(test_pbuf_split_64k_on_small_pbufs),
TESTFUNC(test_pbuf_queueing_bigger_than_64k)
TESTFUNC(test_pbuf_queueing_bigger_than_64k),
TESTFUNC(test_pbuf_take_at_edge),
TESTFUNC(test_pbuf_get_put_at_edge)
};
return create_suite("PBUF", tests, sizeof(tests)/sizeof(testfunc), pbuf_setup, pbuf_teardown);
}