diff options
| -rw-r--r-- | include/linux/ipc_router.h | 4 | ||||
| -rw-r--r-- | net/ipc_router/ipc_router_core.c | 71 | ||||
| -rw-r--r-- | net/ipc_router/ipc_router_private.h | 3 |
3 files changed, 75 insertions, 3 deletions
diff --git a/include/linux/ipc_router.h b/include/linux/ipc_router.h index c89b972a91bd..ad2192d89e0d 100644 --- a/include/linux/ipc_router.h +++ b/include/linux/ipc_router.h @@ -53,8 +53,10 @@ union rr_control_msg { uint32_t cmd; struct { uint32_t cmd; - uint32_t magic; + uint32_t checksum; + uint32_t versions; uint32_t capability; + uint32_t reserved; } hello; struct { uint32_t cmd; diff --git a/net/ipc_router/ipc_router_core.c b/net/ipc_router/ipc_router_core.c index 2e884aa9fb8c..99486e9ac703 100644 --- a/net/ipc_router/ipc_router_core.c +++ b/net/ipc_router/ipc_router_core.c @@ -217,6 +217,40 @@ static void init_routing_table(void) } /** + * ipc_router_calc_checksum() - compute the checksum for extended HELLO message + * @msg: Reference to the IPC Router HELLO message. + * + * Return: Computed checksum value, 0 if msg is NULL. + */ +static uint32_t ipc_router_calc_checksum(union rr_control_msg *msg) +{ + uint32_t checksum = 0; + int i, len; + uint16_t upper_nb; + uint16_t lower_nb; + void *hello; + + if (!msg) + return checksum; + hello = msg; + len = sizeof(*msg); + + for (i = 0; i < len/IPCR_WORD_SIZE; i++) { + lower_nb = (*((uint32_t *)hello)) & IPC_ROUTER_CHECKSUM_MASK; + upper_nb = ((*((uint32_t *)hello)) >> 16) & + IPC_ROUTER_CHECKSUM_MASK; + checksum = checksum + upper_nb + lower_nb; + hello = ((uint32_t *)hello) + 1; + } + while (checksum > 0xFFFF) + checksum = (checksum & IPC_ROUTER_CHECKSUM_MASK) + + ((checksum >> 16) & IPC_ROUTER_CHECKSUM_MASK); + + checksum = ~checksum & IPC_ROUTER_CHECKSUM_MASK; + return checksum; +} + +/** * skb_copy_to_log_buf() - copies the required number bytes from the skb_queue * @skb_head: skb_queue head that contains the data. * @pl_len: length of payload need to be copied. @@ -2379,8 +2413,37 @@ int ipc_router_set_conn(struct msm_ipc_port *port_ptr, return 0; } +/** + * do_version_negotiation() - perform a version negotiation and set the version + * @xprt_info: Pointer to the IPC Router transport info structure. + * @msg: Pointer to the IPC Router HELLO message. + * + * This function performs the version negotiation by verifying the computed + * checksum first. If the checksum matches with the magic number, it sets the + * negotiated IPC Router version in transport. + */ +static void do_version_negotiation(struct msm_ipc_router_xprt_info *xprt_info, + union rr_control_msg *msg) +{ + uint32_t magic; + unsigned version; + + if (!xprt_info) + return; + magic = ipc_router_calc_checksum(msg); + if (magic == IPC_ROUTER_HELLO_MAGIC) { + version = fls(msg->hello.versions & IPC_ROUTER_VER_BITMASK) - 1; + /*Bit 0 & 31 are reserved for future usage*/ + if ((version > 0) && + (version != (sizeof(version) * BITS_PER_BYTE - 1)) && + xprt_info->xprt->set_version) + xprt_info->xprt->set_version(xprt_info->xprt, version); + } +} + static int process_hello_msg(struct msm_ipc_router_xprt_info *xprt_info, - struct rr_header_v1 *hdr) + union rr_control_msg *msg, + struct rr_header_v1 *hdr) { int i, rc = 0; union rr_control_msg ctl; @@ -2397,9 +2460,13 @@ static int process_hello_msg(struct msm_ipc_router_xprt_info *xprt_info, } kref_put(&rt_entry->ref, ipc_router_release_rtentry); + do_version_negotiation(xprt_info, msg); /* Send a reply HELLO message */ memset(&ctl, 0, sizeof(ctl)); ctl.hello.cmd = IPC_ROUTER_CTRL_CMD_HELLO; + ctl.hello.checksum = IPC_ROUTER_HELLO_MAGIC; + ctl.hello.versions = (uint32_t)IPC_ROUTER_VER_BITMASK; + ctl.hello.checksum = ipc_router_calc_checksum(&ctl); rc = ipc_router_send_ctl_msg(xprt_info, &ctl, IPC_ROUTER_DUMMY_DEST_NODE); if (rc < 0) { @@ -2599,7 +2666,7 @@ static int process_control_msg(struct msm_ipc_router_xprt_info *xprt_info, switch (msg->cmd) { case IPC_ROUTER_CTRL_CMD_HELLO: - rc = process_hello_msg(xprt_info, hdr); + rc = process_hello_msg(xprt_info, msg, hdr); break; case IPC_ROUTER_CTRL_CMD_RESUME_TX: rc = process_resume_tx_msg(msg, pkt); diff --git a/net/ipc_router/ipc_router_private.h b/net/ipc_router/ipc_router_private.h index 465bf4149f1b..2dc0a0ff5fdb 100644 --- a/net/ipc_router/ipc_router_private.h +++ b/net/ipc_router/ipc_router_private.h @@ -32,6 +32,9 @@ * with an existing alternate transport in user-space, if needed. */ #define IPC_ROUTER_V2 3 +#define IPC_ROUTER_VER_BITMASK ((BIT(IPC_ROUTER_V1)) | (BIT(IPC_ROUTER_V2))) +#define IPC_ROUTER_HELLO_MAGIC 0xE110 +#define IPC_ROUTER_CHECKSUM_MASK 0xFFFF #define IPC_ROUTER_ADDRESS 0x0000FFFF |