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Fixed framing error for resposnses received from cache with header modification #1831

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Merged
merged 11 commits into from
Jun 7, 2023
Merged

Fixed framing error for resposnses received from cache with header modification #1831

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3419a3d
Added tfw_hpack_decode_int() and tfw_hpack_find_hdr_idx()
const-t Apr 26, 2023
2a17fdd
H2 headers modification reimplemented
const-t Apr 27, 2023
5c94b97
Removed h2 related logic from `tfw_cache_h2_decode_write()`
const-t Mar 1, 2023
5e82598
Removed lambda versions macroses GET_FLEXIBLE and GET_CONTINUE
const-t May 2, 2023
83fa30c
To TfwHdrMods added bitmap with static table indexes for
const-t May 16, 2023
ff2fefc
Changed type of `sz` and `spec_num` to unsigned int
const-t May 17, 2023
31dac6a
Fixed wrong length calculation of tdb chunk
const-t May 18, 2023
69d42b4
Changed way we place headers into cache
const-t May 18, 2023
ebd42d0
`__hdr_name_cmp()` changed to function compares linear memory
const-t May 17, 2023
5b6d9ec
TfwCStr comment fixed
const-t Jun 5, 2023
4f528ae
Little code improvements
const-t Jun 5, 2023
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2 changes: 1 addition & 1 deletion db/core/main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -90,7 +90,7 @@ tdb_entry_get_room(TDB *db, TdbVRec **r, char *curr_ptr, size_t tail_len,
if (likely((*r)->data + (*r)->len - curr_ptr >= tail_len))
return curr_ptr;

(*r)->len -= curr_ptr - (*r)->data;
(*r)->len = curr_ptr - (*r)->data;

*r = tdb_htrie_extend_rec(db->hdr, *r, tot_size);
return *r ? (*r)->data : NULL;
Expand Down
131 changes: 110 additions & 21 deletions fw/cache.c
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Original file line number Diff line number Diff line change
Expand Up @@ -178,15 +178,26 @@ __tfw_dbg_dump_ce(const TfwCacheEntry *ce)
#define __tfw_dbg_dump_ce(...)
#endif

/* TfwCStr contains duplicated header. */
#define TFW_CSTR_DUPLICATE TFW_STR_DUPLICATE
/* TfwCStr contains special header and its id. */
#define TFW_CSTR_SPEC_IDX 0x2

/**
* String header for cache entries used for TfwStr serialization.
*
* @flags - only TFW_STR_DUPLICATE or zero;
* @len - string length or number of duplicates;
* @flags - TFW_CSTR_DUPLICATE and TFW_CSTR_HPACK_IDX or zero;
* @name_len - Header name length. Used for raw headers;
* @name_len_sz - HPACK int size of @name_len;
* @len - Total string length or number of duplicates;
* @idx - HPACK static index or index of special header;
*/
typedef struct {
unsigned long flags : 8,
len : 56;
name_len: 11,
name_len_sz : 2,
len : 35,
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len should be commented above

idx : 8;
} TfwCStr;

#define TFW_CSTR_MAXLEN (1UL << 56)
Expand Down Expand Up @@ -685,9 +696,7 @@ tfw_cache_h2_decode_write(TDB *db, TdbVRec **trec, TfwHttpResp *resp,
acc += m_len;
*data += m_len;
if (acc == len) {
bzero_fast(dc_iter->__off,
sizeof(*dc_iter)
- offsetof(TfwDecodeCacheIter, __off));
TFW_STR_INIT(&dc_iter->hdr_data);
break;
}

Expand Down Expand Up @@ -760,6 +769,52 @@ tfw_cache_set_status(TDB *db, TfwCacheEntry *ce, TfwHttpResp *resp,
return 0;
}

static bool
tfw_cache_skip_hdr(const TfwCStr *str, char *p, const TfwHdrMods *h_mods)
{
unsigned int i;
const TfwHdrModsDesc *desc;
/*
* Move to beggining of the header name. Skip first byte of HPACK
* string and name length size.
*/
TfwStr hdr = { .data = p + str->name_len_sz + 1,
.len = str->name_len };

/* Fast path for special headers */
if (str->flags & TFW_CSTR_SPEC_IDX) {
desc = h_mods->spec_hdrs[str->idx];
/* Skip only resp_hdr_set headers */
return desc ? !desc->append : false;
}

if (str->idx) {
unsigned short hpack_idx = str->idx;

if (hpack_idx <= HPACK_STATIC_TABLE_REGULAR)
return false;

return test_bit(hpack_idx, h_mods->s_tbl);
}

for (i = h_mods->spec_num; i < h_mods->sz; ++i) {
char* mod_hdr_name;
size_t mod_hdr_len;

desc = &h_mods->hdrs[i];
mod_hdr_len = TFW_STR_CHUNK(desc->hdr, 0)->len;
if (desc->append || mod_hdr_len != hdr.len)
continue;

mod_hdr_name = TFW_STR_CHUNK(desc->hdr, 0)->data;

if (!tfw_cstricmp(hdr.data, mod_hdr_name, hdr.len))
return true;
}

return false;
}

/**
* Write HTTP header to skb data.
*/
Expand All @@ -769,32 +824,49 @@ tfw_cache_build_resp_hdr(TDB *db, TfwHttpResp *resp, TfwHdrMods *hmods,
bool skip)
{
tfw_cache_write_actor_t *write_actor;
TfwCStr *s = (TfwCStr *)*p;
TfwCStr *s;
TfwHttpReq *req = resp->req;
TfwDecodeCacheIter dc_iter = { .h_mods = hmods, .skip = skip};
TfwDecodeCacheIter dc_iter = { .h_mods = hmods, .skip = skip };
int d, dn, r = 0;

/* Go to the next chunk if we at the end of current. */
#define NEXT_CHUNK() \
do { \
if (*p - (*trec)->data == (*trec)->len) { \
*trec = tdb_next_rec_chunk(db, (*trec)); \
*p = (*trec)->data; \
} \
} while (0)

BUG_ON(!req);

write_actor = !TFW_MSG_H2(req) || dc_iter.h_mods
? tfw_cache_h2_decode_write
: tfw_cache_h2_write;
write_actor = !TFW_MSG_H2(req) ? tfw_cache_h2_decode_write
: tfw_cache_h2_write;

NEXT_CHUNK();
s = (TfwCStr *)*p;
*p += TFW_CSTR_HDRLEN;
BUG_ON(*p > (*trec)->data + (*trec)->len);

if (likely(!(s->flags & TFW_STR_DUPLICATE))) {
if (likely(!(s->flags & TFW_CSTR_DUPLICATE))) {
if (!skip && dc_iter.h_mods)
dc_iter.skip = tfw_cache_skip_hdr(s, *p, hmods);
r = write_actor(db, trec, resp, p, s->len, &dc_iter);
if (likely(!r))
*acc_len += dc_iter.acc_len;
return r;
}

if (!skip && dc_iter.h_mods)
dc_iter.skip = tfw_cache_skip_hdr((TfwCStr *)*p,
*p + TFW_CSTR_HDRLEN, hmods);

/* Process duplicated headers. */
dn = s->len;
for (d = 0; d < dn; ++d) {
NEXT_CHUNK();
s = (TfwCStr *)*p;
BUG_ON(s->flags);
BUG_ON(s->flags & TFW_CSTR_DUPLICATE);
*p += TFW_CSTR_HDRLEN;
r = write_actor(db, trec, resp, p, s->len, &dc_iter);
if (unlikely(r))
Expand Down Expand Up @@ -1152,10 +1224,13 @@ do { \
ce->hdr_len += TFW_CSTR_HDRLEN; \
} while (0)

#define CSTR_WRITE_HDR(f, l) \
do { \
cs->flags = f; \
cs->len = l; \
#define CSTR_WRITE_HDR(f, l, nl, i) \
do { \
cs->flags = f; \
cs->len = l; \
cs->name_len = nl; \
cs->name_len_sz = tfw_hpack_int_size(nl, 0x7f); \
cs->idx = i; \
} while (0)

/**
Expand Down Expand Up @@ -1474,9 +1549,11 @@ tfw_cache_h2_copy_hdr(TfwCacheEntry *ce, TfwHttpResp *resp, int hid, char **p,
h_len = tfw_h2_hdr_size(s_nm.len, s_val.len, st_index) +
2 * need_extra_quotes;

/* Don't split short strings. */
/* Don't split short strings and header name. */
if (sizeof(TfwCStr) + h_len <= L1_CACHE_BYTES)
n += h_len;
else
n += s_nm.len;
}

*p = tdb_entry_get_room(node_db(), trec, *p, n, *tot_len);
Expand All @@ -1487,7 +1564,12 @@ tfw_cache_h2_copy_hdr(TfwCacheEntry *ce, TfwHttpResp *resp, int hid, char **p,

if (TFW_STR_DUP(hdr)) {
CSTR_MOVE_HDR();
CSTR_WRITE_HDR(TFW_STR_DUPLICATE, hdr->nchunks);
if (hid >= TFW_HTTP_HDR_REGULAR && hid < TFW_HTTP_HDR_RAW)
CSTR_WRITE_HDR(TFW_CSTR_SPEC_IDX | TFW_CSTR_DUPLICATE,
hdr->nchunks, 0, hid);
else
CSTR_WRITE_HDR(TFW_CSTR_DUPLICATE, hdr->nchunks, 0,
st_index);
}

TFW_STR_FOR_EACH_DUP(dup, hdr, dup_end) {
Expand All @@ -1498,6 +1580,8 @@ tfw_cache_h2_copy_hdr(TfwCacheEntry *ce, TfwHttpResp *resp, int hid, char **p,
TFW_STR_INIT(&s_val);
tfw_http_hdr_split(dup, &s_nm, &s_val, true);
st_index = dup->hpack_idx;
*p = tdb_entry_get_room(node_db(), trec, *p,
n + s_nm.len, *tot_len);
}
CSTR_MOVE_HDR();
prev_len = ce->hdr_len;
Expand Down Expand Up @@ -1525,7 +1609,12 @@ tfw_cache_h2_copy_hdr(TfwCacheEntry *ce, TfwHttpResp *resp, int hid, char **p,
need_extra_quotes))
return -ENOMEM;

CSTR_WRITE_HDR(0, ce->hdr_len - prev_len);
if (hid >= TFW_HTTP_HDR_REGULAR && hid < TFW_HTTP_HDR_RAW)
CSTR_WRITE_HDR(TFW_CSTR_SPEC_IDX,
ce->hdr_len - prev_len, 0, hid);
else
CSTR_WRITE_HDR(0, ce->hdr_len - prev_len, s_nm.len,
st_index);
}

T_DBG3("%s: p=[%p], trec=[%p], ce->hdr_len='%u', tot_len='%zu'\n",
Expand Down Expand Up @@ -1576,7 +1665,7 @@ tfw_cache_h2_add_hdr(TfwCacheEntry *ce, char **p, TdbVRec **trec,
if (tfw_cache_h2_copy_str(&ce->hdr_len, p, trec, val, tot_len))
return -ENOMEM;

CSTR_WRITE_HDR(0, ce->hdr_len - prev_len - TFW_CSTR_HDRLEN);
CSTR_WRITE_HDR(0, ce->hdr_len - prev_len - TFW_CSTR_HDRLEN, 0, st_idx);

return ce->hdr_len - prev_len;
}
Expand Down
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