diff options
Diffstat (limited to 'src/gsm/ipa.c')
| -rw-r--r-- | src/gsm/ipa.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/src/gsm/ipa.c b/src/gsm/ipa.c index 447e8e3d..93e34df2 100644 --- a/src/gsm/ipa.c +++ b/src/gsm/ipa.c @@ -30,6 +30,7 @@ #include <stdint.h> #include <errno.h> #include <stdlib.h> +#include <inttypes.h> #include <sys/types.h> @@ -718,4 +719,32 @@ struct msgb *ipa_msg_alloc(int headroom) return nmsg; } +/*! Segmentation callback used by libosmo-netif streaming backend + * See definition of `struct osmo_io_ops` for callback semantics + * \param[in] msg Original `struct msgb` received via osmo_io + * \returns The total packet length indicated by the first header, + * otherwise + * -EAGAIN, if the header has not been read yet, + * -ENOBUFS, if the header declares a payload too large + */ +int ipa_segmentation_cb(struct msgb *msg) +{ + const struct ipaccess_head *hh = (const struct ipaccess_head *) msg->data; + size_t payload_len, total_len; + size_t available = msgb_length(msg) + msgb_tailroom(msg); + if (msgb_length(msg) < sizeof(*hh)) { + /* Haven't even read the entire header */ + return -EAGAIN; + } + payload_len = osmo_ntohs(hh->len); + total_len = sizeof(*hh) + payload_len; + if (OSMO_UNLIKELY(available < total_len)) { + LOGP(DLINP, LOGL_ERROR, "Not enough space left in message buffer. " + "Have %zu octets, but need %zu\n", + available, total_len); + return -ENOBUFS; + } + return total_len; +} + /*! @} */ |