MINOR: quic: refactor qc_build_pkt() error handling

qc_build_pkt() error handling was difficult due to multiple error code
possible. Improve this by defining a proper enum to describe the various
error code. Also clean up ending labels inside qc_build_pkt().
This commit is contained in:
Amaury Denoyelle 2024-06-06 11:59:34 +02:00
parent ab37b86921
commit 88681681cc
2 changed files with 45 additions and 37 deletions

View File

@ -56,4 +56,12 @@ struct quic_tx_packet {
unsigned char type;
};
/* Return value for qc_build_pkt(). */
enum qc_build_pkt_err {
QC_BUILD_PKT_ERR_NONE = 0,
QC_BUILD_PKT_ERR_ALLOC, /* memory allocation failure */
QC_BUILD_PKT_ERR_ENCRYPT, /* error during encryption operation */
QC_BUILD_PKT_ERR_BUFROOM, /* no more room in input buf or congestion window */
};
#endif /* _HAPROXY_TX_T_H */

View File

@ -32,7 +32,8 @@ static struct quic_tx_packet *qc_build_pkt(unsigned char **pos, const unsigned c
struct quic_enc_level *qel, struct quic_tls_ctx *ctx,
struct list *frms, struct quic_conn *qc,
const struct quic_version *ver, size_t dglen, int pkt_type,
int must_ack, int padding, int probe, int cc, int *err);
int must_ack, int padding, int probe, int cc,
enum qc_build_pkt_err *err);
static void quic_packet_encrypt(unsigned char *payload, size_t payload_len,
unsigned char *aad, size_t aad_len, uint64_t pn,
@ -533,9 +534,10 @@ static int qc_prep_pkts(struct quic_conn *qc, struct buffer *buf,
* of the first packet in the datagram (QUIC_DGRAM_HEADLEN).
*/
while (b_contig_space(buf) > QUIC_DGRAM_HEADLEN || prv_pkt) {
int err, probe, must_ack;
int probe, must_ack;
enum quic_pkt_type pkt_type;
struct quic_tx_packet *cur_pkt;
enum qc_build_pkt_err err;
TRACE_PROTO("TX prep pkts", QUIC_EV_CONN_PHPKTS, qc, qel);
probe = 0;
@ -601,29 +603,34 @@ static int qc_prep_pkts(struct quic_conn *qc, struct buffer *buf,
qc, ver, dglen, pkt_type,
must_ack, padding && !next_qel,
probe, cc, &err);
switch (err) {
case -3:
if (!cur_pkt) {
switch (err) {
case QC_BUILD_PKT_ERR_ALLOC:
if (first_pkt)
qc_txb_store(buf, dglen, first_pkt);
qc_purge_tx_buf(qc, buf);
goto leave;
case -2:
break;
case QC_BUILD_PKT_ERR_ENCRYPT:
// trace already emitted by function above
goto leave;
case -1:
/* If there was already a correct packet present, set the
* current datagram as prepared into <cbuf>.
*/
if (prv_pkt)
break;
case QC_BUILD_PKT_ERR_BUFROOM:
if (first_pkt)
qc_txb_store(buf, dglen, first_pkt);
TRACE_PROTO("could not prepare anymore packet", QUIC_EV_CONN_PHPKTS, qc, qel);
goto out;
default:
break;
default:
ABORT_NOW(); /* error case not handled */
break;
}
if (err == QC_BUILD_PKT_ERR_ALLOC || err == QC_BUILD_PKT_ERR_ENCRYPT)
goto leave;
goto out;
}
/* This is to please to GCC. We cannot have (err >= 0 && !cur_pkt) */
BUG_ON(!cur_pkt);
total += cur_pkt->len;
dglen += cur_pkt->len;
@ -2051,12 +2058,8 @@ static inline void quic_tx_packet_init(struct quic_tx_packet *pkt, int type)
* the end of this buffer, with <pkt_type> as packet type for <qc> QUIC connection
* at <qel> encryption level with <frms> list of prebuilt frames.
*
* Return -3 if the packet could not be allocated, -2 if could not be encrypted for
* any reason, -1 if there was not enough room to build a packet.
* XXX NOTE XXX
* If you provide provide qc_build_pkt() with a big enough buffer to build a packet as big as
* possible (to fill an MTU), the unique reason why this function may fail is the congestion
* control window limitation.
* Return built packet instance or NULL on error. <err> will be set to the
* specific error encountered.
*/
static struct quic_tx_packet *qc_build_pkt(unsigned char **pos,
const unsigned char *end,
@ -2064,9 +2067,9 @@ static struct quic_tx_packet *qc_build_pkt(unsigned char **pos,
struct quic_tls_ctx *tls_ctx, struct list *frms,
struct quic_conn *qc, const struct quic_version *ver,
size_t dglen, int pkt_type, int must_ack,
int padding, int probe, int cc, int *err)
int padding, int probe, int cc,
enum qc_build_pkt_err *err)
{
struct quic_tx_packet *ret_pkt = NULL;
/* The pointer to the packet number field. */
unsigned char *buf_pn;
unsigned char *first_byte, *last_byte, *payload;
@ -2077,11 +2080,11 @@ static struct quic_tx_packet *qc_build_pkt(unsigned char **pos,
TRACE_ENTER(QUIC_EV_CONN_TXPKT, qc);
TRACE_PROTO("TX pkt build", QUIC_EV_CONN_TXPKT, qc, NULL, qel);
*err = 0;
*err = QC_BUILD_PKT_ERR_NONE;
pkt = pool_alloc(pool_head_quic_tx_packet);
if (!pkt) {
TRACE_DEVEL("Not enough memory for a new packet", QUIC_EV_CONN_TXPKT, qc);
*err = -3;
*err = QC_BUILD_PKT_ERR_ALLOC;
goto err;
}
@ -2094,7 +2097,7 @@ static struct quic_tx_packet *qc_build_pkt(unsigned char **pos,
if (!qc_do_build_pkt(*pos, end, dglen, pkt, pn, &pn_len, &buf_pn,
must_ack, padding, cc, probe, qel, qc, ver, frms)) {
// trace already emitted by function above
*err = -1;
*err = QC_BUILD_PKT_ERR_BUFROOM;
goto err;
}
@ -2107,7 +2110,7 @@ static struct quic_tx_packet *qc_build_pkt(unsigned char **pos,
if (encrypt_failure) {
/* TODO Unrecoverable failure, unencrypted data should be returned to the caller. */
WARN_ON("quic_packet_encrypt failure");
*err = -2;
*err = QC_BUILD_PKT_ERR_ENCRYPT;
goto err;
}
@ -2117,7 +2120,7 @@ static struct quic_tx_packet *qc_build_pkt(unsigned char **pos,
if (encrypt_failure) {
/* TODO Unrecoverable failure, unencrypted data should be returned to the caller. */
WARN_ON("quic_apply_header_protection failure");
*err = -2;
*err = QC_BUILD_PKT_ERR_ENCRYPT;
goto err;
}
@ -2154,18 +2157,15 @@ static struct quic_tx_packet *qc_build_pkt(unsigned char **pos,
pkt->pktns = qel->pktns;
ret_pkt = pkt;
leave:
TRACE_PROTO("TX pkt built", QUIC_EV_CONN_TXPKT, qc, ret_pkt);
TRACE_PROTO("TX pkt built", QUIC_EV_CONN_TXPKT, qc, pkt);
TRACE_LEAVE(QUIC_EV_CONN_TXPKT, qc);
return ret_pkt;
return pkt;
err:
/* TODO: what about the frames which have been built
* for this packet.
*/
/* TODO What about the frames which have been built for this packet? */
free_quic_tx_packet(qc, pkt);
goto leave;
TRACE_DEVEL("leaving on error", QUIC_EV_CONN_TXPKT, qc);
return NULL;
}
/*
* Local variables: