diff options
| author | Vadim Yanitskiy <axilirator@gmail.com> | 2018-03-09 06:34:04 +0700 |
|---|---|---|
| committer | Harald Welte <laforge@gnumonks.org> | 2018-03-11 10:05:48 +0000 |
| commit | 2136891b7bbdfbd62f28f63c8a16711d9562ec1c (patch) | |
| tree | c3c07e1c856d2e506895c4388e375c38b60a2464 | |
| parent | a92fd3388cd7eac69e18938832be688c9a425613 (diff) | |
trxcon: clarify L1CTL message length field
Each L1CTL message gets its own length pushed in front before
sending. This isn't specified in the 'l1ctl_proto.h', but
assumed in the code. Let's clarify this.
Change-Id: I118d00613aeaf5ff0bad1188fa5f7450d4ca8122
| -rw-r--r-- | src/host/trxcon/l1ctl.c | 8 | ||||
| -rw-r--r-- | src/host/trxcon/l1ctl_link.c | 8 | ||||
| -rw-r--r-- | src/host/trxcon/l1ctl_link.h | 8 |
3 files changed, 19 insertions, 5 deletions
diff --git a/src/host/trxcon/l1ctl.c b/src/host/trxcon/l1ctl.c index 58b8a4ff..f138b88c 100644 --- a/src/host/trxcon/l1ctl.c +++ b/src/host/trxcon/l1ctl.c @@ -49,8 +49,14 @@ static struct msgb *l1ctl_alloc_msg(uint8_t msg_type) { struct l1ctl_hdr *l1h; - struct msgb *msg = msgb_alloc_headroom(256, 4, "l1ctl_tx_msg"); + struct msgb *msg; + /** + * Each L1CTL message gets its own length pushed in front + * before sending. This is why we need this small headroom. + */ + msg = msgb_alloc_headroom(L1CTL_LENGTH + L1CTL_MSG_LEN_FIELD, + L1CTL_MSG_LEN_FIELD, "l1ctl_tx_msg"); if (!msg) { LOGP(DL1C, LOGL_ERROR, "Failed to allocate memory\n"); return NULL; diff --git a/src/host/trxcon/l1ctl_link.c b/src/host/trxcon/l1ctl_link.c index a7277ea5..0fa3efe5 100644 --- a/src/host/trxcon/l1ctl_link.c +++ b/src/host/trxcon/l1ctl_link.c @@ -84,8 +84,8 @@ static int l1ctl_link_read_cb(struct osmo_fd *bfd) } /* Attempt to read from socket */ - rc = read(bfd->fd, &len, sizeof(len)); - if (rc < sizeof(len)) { + rc = read(bfd->fd, &len, L1CTL_MSG_LEN_FIELD); + if (rc < L1CTL_MSG_LEN_FIELD) { LOGP(DL1D, LOGL_NOTICE, "L1CTL has lost connection\n"); msgb_free(msg); if (rc >= 0) @@ -198,8 +198,8 @@ int l1ctl_link_send(struct l1ctl_link *l1l, struct msgb *msg) LOGP(DL1D, LOGL_INFO, "Message L1 header != Message Data\n"); /* Prepend 16-bit length before sending */ - len = (uint16_t *) msgb_push(msg, sizeof(*len)); - *len = htons(msg->len - sizeof(*len)); + len = (uint16_t *) msgb_push(msg, L1CTL_MSG_LEN_FIELD); + *len = htons(msg->len - L1CTL_MSG_LEN_FIELD); if (osmo_wqueue_enqueue(&l1l->wq, msg) != 0) { LOGP(DL1D, LOGL_ERROR, "Failed to enqueue msg!\n"); diff --git a/src/host/trxcon/l1ctl_link.h b/src/host/trxcon/l1ctl_link.h index f9d91f14..01103dcc 100644 --- a/src/host/trxcon/l1ctl_link.h +++ b/src/host/trxcon/l1ctl_link.h @@ -1,5 +1,7 @@ #pragma once +#include <stdint.h> + #include <osmocom/core/write_queue.h> #include <osmocom/core/select.h> #include <osmocom/core/timer.h> @@ -9,6 +11,12 @@ #define L1CTL_LENGTH 256 #define L1CTL_HEADROOM 32 +/** + * Each L1CTL message gets its own length pushed + * as two bytes in front before sending. + */ +#define L1CTL_MSG_LEN_FIELD 2 + /* Forward declaration to avoid mutual include */ struct trx_instance; |