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authorDimitri Staessens <dimitri.staessens@ugent.be>2017-11-08 19:25:48 +0100
committerSander Vrijders <sander.vrijders@ugent.be>2017-11-08 21:40:28 +0100
commit35c43358a110758090b48dd18628bb285ffddfc6 (patch)
tree9746475ac579e516e86f720a3bcb107bf6e36784 /src/lib/frct.c
parentc59053040ce927f2926e5a569b19bdd129c354a7 (diff)
downloadouroboros-35c43358a110758090b48dd18628bb285ffddfc6.tar.gz
ouroboros-35c43358a110758090b48dd18628bb285ffddfc6.zip
lib: Use packed struct for FRCT header access
This replaces the variable FRCT header with a packed struct, which significantly simplifies the implementation. The shm_du_buff calls to release the head/tail are updated to return a pointer to the original head or the new tail (in symmetry to the alloc calls, which return a pointer to the new head and old tail), so that it immediately points to the structure that is needed. The frct_pci sources are removed and frct is now fully in the frct.c source file. Signed-off-by: Dimitri Staessens <dimitri.staessens@ugent.be> Signed-off-by: Sander Vrijders <sander.vrijders@ugent.be>
Diffstat (limited to 'src/lib/frct.c')
-rw-r--r--src/lib/frct.c177
1 files changed, 125 insertions, 52 deletions
diff --git a/src/lib/frct.c b/src/lib/frct.c
index abebb2ff..5f45f522 100644
--- a/src/lib/frct.c
+++ b/src/lib/frct.c
@@ -30,16 +30,20 @@
#define TW_ELEMENTS 6000
#define TW_RESOLUTION 1 /* ms */
+#define FRCT_PCILEN (sizeof(struct frct_pci))
+#define FRCT_CRCLEN (sizeof(uint32_t))
+
struct frct_cr {
- bool drf;
- uint64_t lwe;
- uint64_t rwe;
+ bool drf;
+ uint32_t lwe;
+ uint32_t rwe;
- bool conf;
- uint16_t cflags;
+ uint32_t seqno;
+ bool conf;
+ uint8_t cflags;
- time_t act;
- time_t inact;
+ time_t act;
+ time_t inact;
};
struct frcti {
@@ -63,6 +67,28 @@ struct {
struct timerwheel * tw;
} frct;
+enum frct_flags {
+ FRCT_DATA = 0x01, /* PDU carries data */
+ FRCT_DRF = 0x02, /* Data run flag */
+ FRCT_ACK = 0x03, /* ACK field valid */
+ FRCT_FC = 0x08, /* FC window valid */
+ FRCT_RDVZ = 0x10, /* Rendez-vous */
+ FRCT_CFG = 0x20, /* Configuration */
+ FRCT_MFGM = 0x40, /* More fragments */
+ FRCT_CRC = 0x80, /* CRC present */
+};
+
+struct frct_pci {
+ uint8_t flags;
+
+ uint8_t cflags;
+
+ uint16_t window;
+
+ uint32_t seqno;
+ uint32_t ackno;
+} __attribute__((packed));
+
static int frct_init(void)
{
frct.tw = timerwheel_create(TW_RESOLUTION, TW_RESOLUTION * TW_ELEMENTS);
@@ -104,6 +130,11 @@ static struct frcti * frcti_create(int fd)
frcti->snd_cr.drf = true;
frcti->snd_cr.conf = true;
+#ifdef OUROBOROS_CONFIG_DEBUG
+ frcti->snd_cr.seqno = 0;
+#else
+ random_buffer(&frcti->snd_cr.seqno, sizeof(frcti->snd_cr.seqno));
+#endif
frcti->snd_cr.lwe = 0;
frcti->snd_cr.rwe = 0;
frcti->snd_cr.cflags = 0;
@@ -201,44 +232,79 @@ static ssize_t __frcti_queued_pdu(struct frcti * frcti)
return idx;
}
+static int frct_chk_crc(uint8_t * head,
+ uint8_t * tail)
+{
+ uint32_t crc;
+
+ mem_hash(HASH_CRC32, &crc, head, tail - head);
+
+ return crc == *((uint32_t *) tail);
+}
+
+static void frct_add_crc(uint8_t * head,
+ uint8_t * tail)
+{
+ mem_hash(HASH_CRC32, tail, head, tail - head);
+}
+
+static struct frct_pci * frcti_alloc_head(struct shm_du_buff * sdb)
+{
+ struct frct_pci * pci = NULL;
+
+ pci = (struct frct_pci *) shm_du_buff_head_alloc(sdb, FRCT_PCILEN);
+ if (pci != NULL)
+ memset(pci, 0, sizeof(*pci));
+
+ return pci;
+}
+
static int __frcti_snd(struct frcti * frcti,
struct shm_du_buff * sdb)
{
- struct frct_pci pci;
- struct timespec now;
- struct frct_cr * snd_cr;
+ struct frct_pci * pci;
+ struct timespec now;
+ struct frct_cr * snd_cr;
- if (frcti == NULL)
- return 0;
+ assert(frcti);
snd_cr = &frcti->snd_cr;
- memset(&pci, 0, sizeof(pci));
+ pci = frcti_alloc_head(sdb);
+ if (pci == NULL)
+ return -1;
clock_gettime(CLOCK_REALTIME_COARSE, &now);
- pci.type |= PDU_TYPE_DATA;
-
pthread_rwlock_wrlock(&frcti->lock);
/* Check if sender is inactive. */
if (!snd_cr->drf && now.tv_sec - snd_cr->act > snd_cr->inact)
snd_cr->drf = true;
+ pci->flags |= FRCT_DATA;
+
/* Set the DRF in the first packet of a new run of SDUs. */
if (snd_cr->drf) {
- pci.flags |= FLAG_DATA_RUN;
+ pci->flags |= FRCT_DRF;
if (snd_cr->conf) {
- pci.type |= PDU_TYPE_CONFIG;
- pci.cflags = snd_cr->cflags;
+ pci->flags |= FRCT_CFG;
+ pci->cflags = snd_cr->cflags;
}
}
- pci.seqno = snd_cr->lwe++;
+ pci->seqno = snd_cr->seqno++;
- if (frct_pci_ser(sdb, &pci, snd_cr->cflags & FRCTFERRCHCK)) {
- pthread_rwlock_unlock(&frcti->lock);
- return -1;
+ if (snd_cr->cflags & FRCTFERRCHCK) {
+ uint8_t * tail = shm_du_buff_tail_alloc(sdb, FRCT_CRCLEN);
+ if (tail == NULL) {
+ pthread_rwlock_unlock(&frcti->lock);
+ return -1;
+ }
+
+ frct_add_crc((uint8_t *) pci, tail);
+
+ pci->flags |= FRCT_CRC;
}
snd_cr->act = now.tv_sec;
@@ -255,44 +321,55 @@ static int __frcti_snd(struct frcti * frcti,
static int __frcti_rcv(struct frcti * frcti,
struct shm_du_buff * sdb)
{
- ssize_t idx;
- struct frct_pci pci;
- struct timespec now;
- struct frct_cr * rcv_cr;
+ ssize_t idx;
+ struct frct_pci * pci;
+ struct timespec now;
+ struct frct_cr * rcv_cr;
assert(frcti);
rcv_cr = &frcti->rcv_cr;
+ pci = (struct frct_pci *) shm_du_buff_head_release(sdb, FRCT_PCILEN);
+
clock_gettime(CLOCK_REALTIME_COARSE, &now);
pthread_rwlock_wrlock(&frcti->lock);
idx = shm_du_buff_get_idx(sdb);
- /* SDU may be corrupted. */
- if (frct_pci_des(sdb, &pci, rcv_cr->cflags & FRCTFERRCHCK)) {
- pthread_rwlock_unlock(&frcti->lock);
- shm_rdrbuff_remove(ai.rdrb, idx);
- return -EAGAIN;
+ /* PDU may be corrupted. */
+ if (pci->flags & FRCT_CRC) {
+ uint8_t * tail = shm_du_buff_tail_release(sdb, FRCT_CRCLEN);
+ if (frct_chk_crc((uint8_t *) pci, tail))
+ goto fail_clean;
}
/* Check if receiver inactivity is true. */
if (!rcv_cr->drf && now.tv_sec - rcv_cr->act > rcv_cr->inact)
rcv_cr->drf = true;
- /* When there is receiver inactivity and no DRF, drop the SDU. */
- if (rcv_cr->drf && !(pci.flags & FLAG_DATA_RUN)) {
- pthread_rwlock_unlock(&frcti->lock);
- shm_rdrbuff_remove(ai.rdrb, idx);
- return -EAGAIN;
+ /* When there is receiver inactivity and no DRF, drop the PDU. */
+ if (rcv_cr->drf && !(pci->flags & FRCT_DRF))
+ goto fail_clean;
+
+ /* Queue the PDU if needed. */
+ if (rcv_cr->cflags & FRCTFORDERING) {
+ if (pci->seqno != frcti->rcv_cr.lwe) {
+ /* NOTE: queued PDUs head/tail without PCI. */
+ if (rq_push(frcti->rq, pci->seqno, idx))
+ shm_rdrbuff_remove(ai.rdrb, idx);
+ goto fail;
+ } else {
+ ++rcv_cr->lwe;
+ }
}
/* If the DRF is set, reset the state of the connection. */
- if (pci.flags & FLAG_DATA_RUN) {
- rcv_cr->lwe = pci.seqno;
- if (pci.type & PDU_TYPE_CONFIG)
- rcv_cr->cflags = pci.cflags;
+ if (pci->flags & FRCT_DRF) {
+ rcv_cr->lwe = pci->seqno;
+ if (pci->flags & FRCT_CFG)
+ rcv_cr->cflags = pci->cflags;
}
if (rcv_cr->drf)
@@ -300,21 +377,17 @@ static int __frcti_rcv(struct frcti * frcti,
rcv_cr->act = now.tv_sec;
- if (!(pci.type & PDU_TYPE_DATA))
+ if (!(pci->flags & FRCT_DATA))
shm_rdrbuff_remove(ai.rdrb, idx);
- if (rcv_cr->cflags & FRCTFORDERING) {
- if (pci.seqno != frcti->rcv_cr.lwe) {
- if (rq_push(frcti->rq, pci.seqno, idx))
- shm_rdrbuff_remove(ai.rdrb, idx);
- pthread_rwlock_unlock(&frcti->lock);
- return -EAGAIN;
- } else {
- ++rcv_cr->lwe;
- }
- }
-
pthread_rwlock_unlock(&frcti->lock);
return 0;
+
+ fail_clean:
+ if (!(pci->flags & FRCT_DATA))
+ shm_rdrbuff_remove(ai.rdrb, idx);
+ fail:
+ pthread_rwlock_unlock(&frcti->lock);
+ return -EAGAIN;
}