Harald Welte | bd44858 | 2016-12-23 23:41:14 +0100 | [diff] [blame] | 1 | |
| 2 | #include <stdint.h> |
| 3 | #include <stdio.h> |
| 4 | #include <errno.h> |
| 5 | #include <string.h> |
| 6 | #include <unistd.h> |
| 7 | |
| 8 | #include "protocol.h" |
| 9 | #include "diag_io.h" |
| 10 | #include "diagchar_hdlc.h" |
| 11 | |
| 12 | /* transmit a msgb containing a DIAG message over the given fd */ |
| 13 | int diag_transmit_msgb(struct diag_instance *di, struct msgb *msg) |
| 14 | { |
| 15 | int out_len, rc; |
| 16 | uint8_t packet[DIAG_MAX_HDLC_BUF_SIZE]; |
| 17 | struct diag_send_desc_type send; |
| 18 | struct diag_hdlc_dest_type enc = { NULL, NULL, 0 }; |
| 19 | |
| 20 | send.state = DIAG_STATE_START; |
| 21 | send.pkt = msgb_data(msg); |
| 22 | send.last = msgb_data(msg) + msgb_length(msg) - 1; |
| 23 | send.terminate = 1; |
| 24 | |
| 25 | enc.dest = packet; |
| 26 | enc.dest_last = packet + sizeof(packet) - 1; |
| 27 | |
| 28 | diag_hdlc_encode(&send, &enc); |
| 29 | |
| 30 | out_len = (enc.dest - (void *)packet); |
| 31 | |
| 32 | rc = write(di->fd, packet, out_len); |
| 33 | if (rc != out_len) { |
Harald Welte | 98f6fad | 2016-12-24 01:27:49 +0100 | [diff] [blame] | 34 | fprintf(stderr, "Short write on packet.\n"); |
Harald Welte | bd44858 | 2016-12-23 23:41:14 +0100 | [diff] [blame] | 35 | return -1; |
| 36 | } |
| 37 | |
| 38 | msgb_free(msg); |
| 39 | |
| 40 | return 0; |
| 41 | } |
| 42 | |
| 43 | /* transmit a message from a buffer (nto msgb) as DIAG over the given fd */ |
| 44 | int diag_transmit_buf(struct diag_instance *di, const uint8_t *data, size_t data_len) |
| 45 | { |
| 46 | struct msgb *msg = msgb_alloc(DIAG_MAX_REQ_SIZE, "DIAG Tx"); |
| 47 | |
| 48 | memcpy(msg->tail, data, data_len); |
| 49 | msgb_put(msg, data_len); |
| 50 | |
| 51 | return diag_transmit_msgb(di, msg); |
| 52 | } |
| 53 | |
| 54 | int diag_read(struct diag_instance *di) |
| 55 | { |
| 56 | uint8_t buf[DIAG_MAX_HDLC_BUF_SIZE]; |
| 57 | struct diag_hdlc_decode_type hdlc_decode; |
| 58 | struct msgb *msg; |
| 59 | int rc; |
| 60 | |
| 61 | /* read raw data into buffer */ |
| 62 | rc = read(di->fd, buf, sizeof(buf)); |
| 63 | if (rc <= 0 ) { |
| 64 | fprintf(stderr, "Short read!\n"); |
| 65 | return -EIO; |
| 66 | } |
| 67 | |
| 68 | if (!di->rx.msg) { |
| 69 | di->rx.msg = msgb_alloc(DIAG_MAX_REQ_SIZE, "DIAG Rx"); |
| 70 | di->rx.msg->l2h = di->rx.msg->tail; |
| 71 | } |
| 72 | msg = di->rx.msg; |
| 73 | |
| 74 | hdlc_decode.dest_ptr = msg->tail; |
| 75 | hdlc_decode.dest_size = msgb_tailroom(msg); |
| 76 | hdlc_decode.src_ptr = buf; |
| 77 | hdlc_decode.src_size = rc; |
| 78 | hdlc_decode.src_idx = 0; |
| 79 | hdlc_decode.dest_idx = 0; |
| 80 | |
| 81 | rc = diag_hdlc_decode(&hdlc_decode); |
| 82 | |
| 83 | if (msgb_length(msg) + hdlc_decode.dest_idx > DIAG_MAX_REQ_SIZE) { |
| 84 | fprintf(stderr, "Dropping packet. pkt_size: %d, max: %d\n", |
| 85 | msgb_length(msg) + hdlc_decode.dest_idx, |
| 86 | DIAG_MAX_REQ_SIZE); |
| 87 | return -EIO; |
| 88 | } |
| 89 | |
| 90 | msgb_put(msg, hdlc_decode.dest_idx); |
| 91 | |
| 92 | if (rc == HDLC_COMPLETE) { |
| 93 | di->rx.msg = NULL; |
| 94 | rc = crc_check(msgb_data(msg), msgb_length(msg)); |
| 95 | if (rc) { |
| 96 | fprintf(stderr, "Bad CRC, dropping packet\n"); |
| 97 | msgb_free(msg); |
| 98 | return -EINVAL; |
| 99 | } |
| 100 | msgb_get(msg, HDLC_FOOTER_LEN); |
| 101 | |
| 102 | if (msgb_length(msg) < 1) { |
| 103 | fprintf(stderr, "Message too short, len: %u\n", msgb_length(msg)); |
| 104 | msgb_free(msg); |
| 105 | return -EINVAL; |
| 106 | } |
| 107 | |
| 108 | if (di->rx.rcvmsg) |
| 109 | (di->rx.rcvmsg)(di, msg); |
| 110 | else |
| 111 | msgb_free(msg); |
| 112 | } |
| 113 | |
| 114 | return 0; |
| 115 | }; |