Jeremy Kerr | 3d36ee2 | 2019-05-30 11:15:37 +0800 | [diff] [blame] | 1 | /* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */ |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 2 | |
| 3 | #include <assert.h> |
| 4 | #include <stdbool.h> |
| 5 | #include <stdlib.h> |
| 6 | #include <string.h> |
| 7 | #include <unistd.h> |
| 8 | |
Jeremy Kerr | c7e764a | 2019-05-28 16:49:03 +0800 | [diff] [blame] | 9 | #ifdef HAVE_CONFIG_H |
| 10 | #include "config.h" |
| 11 | #endif |
| 12 | |
| 13 | #ifdef MCTP_HAVE_FILEIO |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 14 | #include <fcntl.h> |
Jeremy Kerr | 597b369 | 2019-09-03 16:24:48 +0800 | [diff] [blame] | 15 | #else |
| 16 | static const size_t write(int fd, void *buf, size_t len) |
| 17 | { |
| 18 | return -1; |
| 19 | } |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 20 | #endif |
| 21 | |
| 22 | #define pr_fmt(x) "serial: " x |
| 23 | |
| 24 | #include "libmctp.h" |
| 25 | #include "libmctp-alloc.h" |
| 26 | #include "libmctp-log.h" |
| 27 | #include "libmctp-serial.h" |
| 28 | |
| 29 | struct mctp_binding_serial { |
| 30 | struct mctp_binding binding; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 31 | int fd; |
| 32 | unsigned long bus_id; |
| 33 | |
Jeremy Kerr | 597b369 | 2019-09-03 16:24:48 +0800 | [diff] [blame] | 34 | mctp_serial_tx_fn tx_fn; |
| 35 | void *tx_fn_data; |
| 36 | |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 37 | /* receive buffer and state */ |
| 38 | uint8_t rxbuf[1024]; |
| 39 | struct mctp_pktbuf *rx_pkt; |
| 40 | uint8_t rx_exp_len; |
| 41 | uint16_t rx_fcs; |
| 42 | enum { |
| 43 | STATE_WAIT_SYNC_START, |
| 44 | STATE_WAIT_REVISION, |
| 45 | STATE_WAIT_LEN, |
| 46 | STATE_DATA, |
| 47 | STATE_DATA_ESCAPED, |
| 48 | STATE_WAIT_FCS1, |
| 49 | STATE_WAIT_FCS2, |
| 50 | STATE_WAIT_SYNC_END, |
| 51 | } rx_state; |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 52 | |
| 53 | /* temporary transmit buffer */ |
| 54 | uint8_t txbuf[256]; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 55 | }; |
| 56 | |
| 57 | #ifndef container_of |
| 58 | #define container_of(ptr, type, member) \ |
| 59 | (type *)((char *)(ptr) - (char *)&((type *)0)->member) |
| 60 | #endif |
| 61 | |
| 62 | #define binding_to_serial(b) \ |
| 63 | container_of(b, struct mctp_binding_serial, binding) |
| 64 | |
| 65 | #define MCTP_SERIAL_REVISION 0x01 |
| 66 | #define MCTP_SERIAL_FRAMING_FLAG 0x7e |
| 67 | #define MCTP_SERIAL_ESCAPE 0x7d |
| 68 | |
| 69 | struct mctp_serial_header { |
| 70 | uint8_t flag; |
| 71 | uint8_t revision; |
| 72 | uint8_t len; |
| 73 | }; |
| 74 | |
| 75 | struct mctp_serial_trailer { |
| 76 | uint8_t fcs_msb; |
| 77 | uint8_t fcs_lsb; |
| 78 | uint8_t flag; |
| 79 | }; |
| 80 | |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 81 | static size_t mctp_serial_pkt_escape(struct mctp_pktbuf *pkt, uint8_t *buf) |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 82 | { |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 83 | uint8_t total_len; |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 84 | uint8_t *p; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 85 | int i, j; |
| 86 | |
| 87 | total_len = pkt->end - pkt->mctp_hdr_off; |
| 88 | |
| 89 | p = (void *)mctp_pktbuf_hdr(pkt); |
| 90 | |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 91 | for (i = 0, j = 0; i < total_len; i++, j++) { |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 92 | uint8_t c = p[i]; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 93 | if (c == 0x7e || c == 0x7d) { |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 94 | if (buf) |
| 95 | buf[j] = 0x7d; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 96 | j++; |
| 97 | c ^= 0x20; |
| 98 | } |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 99 | if (buf) |
| 100 | buf[j] = c; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 101 | } |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 102 | |
| 103 | return j; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 104 | } |
| 105 | |
| 106 | static int mctp_binding_serial_tx(struct mctp_binding *b, |
| 107 | struct mctp_pktbuf *pkt) |
| 108 | { |
| 109 | struct mctp_binding_serial *serial = binding_to_serial(b); |
| 110 | struct mctp_serial_header *hdr; |
| 111 | struct mctp_serial_trailer *tlr; |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 112 | uint8_t *buf; |
| 113 | size_t len; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 114 | |
| 115 | /* the length field in the header excludes serial framing |
| 116 | * and escape sequences */ |
| 117 | len = mctp_pktbuf_size(pkt); |
| 118 | |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 119 | hdr = (void *)serial->txbuf; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 120 | hdr->flag = MCTP_SERIAL_FRAMING_FLAG; |
| 121 | hdr->revision = MCTP_SERIAL_REVISION; |
| 122 | hdr->len = len; |
| 123 | |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 124 | buf = (void *)(hdr + 1); |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 125 | |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 126 | len = mctp_serial_pkt_escape(pkt, NULL); |
| 127 | if (len + sizeof(*hdr) + sizeof(*tlr) > sizeof(serial->txbuf)) |
| 128 | return -1; |
| 129 | |
| 130 | mctp_serial_pkt_escape(pkt, buf); |
| 131 | |
| 132 | buf += len; |
| 133 | |
| 134 | tlr = (void *)buf; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 135 | tlr->flag = MCTP_SERIAL_FRAMING_FLAG; |
Jeremy Kerr | c67605b | 2019-02-07 21:52:00 +0800 | [diff] [blame] | 136 | /* todo: trailer FCS */ |
| 137 | tlr->fcs_msb = 0; |
| 138 | tlr->fcs_lsb = 0; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 139 | |
Jeremy Kerr | 597b369 | 2019-09-03 16:24:48 +0800 | [diff] [blame] | 140 | len += sizeof(*hdr) + sizeof(*tlr); |
| 141 | |
| 142 | if (serial->tx_fn) |
| 143 | serial->tx_fn(serial->tx_fn_data, serial->txbuf, len); |
| 144 | else |
| 145 | write(serial->fd, serial->txbuf, len); |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 146 | |
| 147 | return 0; |
| 148 | } |
| 149 | |
| 150 | static void mctp_serial_finish_packet(struct mctp_binding_serial *serial, |
| 151 | bool valid) |
| 152 | { |
| 153 | struct mctp_pktbuf *pkt = serial->rx_pkt; |
| 154 | assert(pkt); |
| 155 | |
| 156 | if (valid) |
Jeremy Kerr | 0a00dca | 2019-03-01 08:01:35 +0800 | [diff] [blame] | 157 | mctp_bus_rx(&serial->binding, pkt); |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 158 | |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 159 | serial->rx_pkt = NULL; |
| 160 | } |
| 161 | |
| 162 | static void mctp_serial_start_packet(struct mctp_binding_serial *serial, |
| 163 | uint8_t len) |
| 164 | { |
Jeremy Kerr | df15f7e | 2019-08-05 15:41:19 +0800 | [diff] [blame] | 165 | serial->rx_pkt = mctp_pktbuf_alloc(&serial->binding, len); |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 166 | } |
| 167 | |
| 168 | static void mctp_rx_consume_one(struct mctp_binding_serial *serial, |
| 169 | uint8_t c) |
| 170 | { |
| 171 | struct mctp_pktbuf *pkt = serial->rx_pkt; |
| 172 | |
| 173 | mctp_prdebug("state: %d, char 0x%02x", serial->rx_state, c); |
| 174 | |
| 175 | assert(!pkt == (serial->rx_state == STATE_WAIT_SYNC_START || |
| 176 | serial->rx_state == STATE_WAIT_REVISION || |
| 177 | serial->rx_state == STATE_WAIT_LEN)); |
| 178 | |
| 179 | switch (serial->rx_state) { |
| 180 | case STATE_WAIT_SYNC_START: |
| 181 | if (c != MCTP_SERIAL_FRAMING_FLAG) { |
| 182 | mctp_prdebug("lost sync, dropping packet"); |
| 183 | if (pkt) |
| 184 | mctp_serial_finish_packet(serial, false); |
| 185 | } else { |
| 186 | serial->rx_state = STATE_WAIT_REVISION; |
| 187 | } |
| 188 | break; |
| 189 | |
| 190 | case STATE_WAIT_REVISION: |
| 191 | if (c == MCTP_SERIAL_REVISION) { |
| 192 | serial->rx_state = STATE_WAIT_LEN; |
| 193 | } else { |
| 194 | mctp_prdebug("invalid revision 0x%02x", c); |
| 195 | serial->rx_state = STATE_WAIT_SYNC_START; |
| 196 | } |
| 197 | break; |
| 198 | case STATE_WAIT_LEN: |
Jeremy Kerr | df15f7e | 2019-08-05 15:41:19 +0800 | [diff] [blame] | 199 | if (c > serial->binding.pkt_size || |
| 200 | c < sizeof(struct mctp_hdr)) { |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 201 | mctp_prdebug("invalid size %d", c); |
| 202 | serial->rx_state = STATE_WAIT_SYNC_START; |
| 203 | } else { |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 204 | mctp_serial_start_packet(serial, 0); |
| 205 | pkt = serial->rx_pkt; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 206 | serial->rx_exp_len = c; |
| 207 | serial->rx_state = STATE_DATA; |
| 208 | } |
| 209 | break; |
| 210 | |
| 211 | case STATE_DATA: |
| 212 | if (c == MCTP_SERIAL_ESCAPE) { |
| 213 | serial->rx_state = STATE_DATA_ESCAPED; |
| 214 | } else { |
| 215 | mctp_pktbuf_push(pkt, &c, 1); |
| 216 | if (pkt->end - pkt->mctp_hdr_off == serial->rx_exp_len) |
| 217 | serial->rx_state = STATE_WAIT_FCS1; |
| 218 | } |
| 219 | break; |
| 220 | |
| 221 | case STATE_DATA_ESCAPED: |
| 222 | c ^= 0x20; |
| 223 | mctp_pktbuf_push(pkt, &c, 1); |
| 224 | if (pkt->end - pkt->mctp_hdr_off == serial->rx_exp_len) |
| 225 | serial->rx_state = STATE_WAIT_FCS1; |
| 226 | else |
| 227 | serial->rx_state = STATE_DATA; |
| 228 | break; |
| 229 | |
| 230 | case STATE_WAIT_FCS1: |
| 231 | serial->rx_fcs = c << 8; |
| 232 | serial->rx_state = STATE_WAIT_FCS2; |
| 233 | break; |
| 234 | case STATE_WAIT_FCS2: |
| 235 | serial->rx_fcs |= c; |
| 236 | /* todo: check fcs */ |
| 237 | serial->rx_state = STATE_WAIT_SYNC_END; |
| 238 | break; |
| 239 | |
| 240 | case STATE_WAIT_SYNC_END: |
| 241 | if (c == MCTP_SERIAL_FRAMING_FLAG) { |
| 242 | mctp_serial_finish_packet(serial, true); |
| 243 | } else { |
| 244 | mctp_prdebug("missing end frame marker"); |
| 245 | mctp_serial_finish_packet(serial, false); |
| 246 | } |
| 247 | serial->rx_state = STATE_WAIT_SYNC_START; |
| 248 | break; |
| 249 | } |
| 250 | |
| 251 | mctp_prdebug(" -> state: %d", serial->rx_state); |
| 252 | } |
Jeremy Kerr | 597b369 | 2019-09-03 16:24:48 +0800 | [diff] [blame] | 253 | static void mctp_rx_consume(struct mctp_binding_serial *serial, |
| 254 | const void *buf, size_t len) |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 255 | { |
| 256 | size_t i; |
| 257 | |
| 258 | for (i = 0; i < len; i++) |
| 259 | mctp_rx_consume_one(serial, *(uint8_t *)(buf + i)); |
| 260 | } |
| 261 | |
Jeremy Kerr | c7e764a | 2019-05-28 16:49:03 +0800 | [diff] [blame] | 262 | #ifdef MCTP_HAVE_FILEIO |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 263 | int mctp_serial_read(struct mctp_binding_serial *serial) |
| 264 | { |
| 265 | ssize_t len; |
| 266 | |
| 267 | len = read(serial->fd, serial->rxbuf, sizeof(serial->rxbuf)); |
| 268 | if (len == 0) |
| 269 | return -1; |
| 270 | |
| 271 | if (len < 0) { |
| 272 | mctp_prerr("can't read from serial device: %m"); |
| 273 | return -1; |
| 274 | } |
| 275 | |
| 276 | mctp_rx_consume(serial, serial->rxbuf, len); |
| 277 | |
| 278 | return 0; |
| 279 | } |
| 280 | |
| 281 | int mctp_serial_get_fd(struct mctp_binding_serial *serial) |
| 282 | { |
| 283 | return serial->fd; |
| 284 | } |
| 285 | |
| 286 | int mctp_serial_open_path(struct mctp_binding_serial *serial, |
| 287 | const char *device) |
| 288 | { |
| 289 | serial->fd = open(device, O_RDWR); |
| 290 | if (serial->fd < 0) |
| 291 | mctp_prerr("can't open device %s: %m", device); |
| 292 | |
| 293 | return 0; |
| 294 | } |
| 295 | |
| 296 | void mctp_serial_open_fd(struct mctp_binding_serial *serial, int fd) |
| 297 | { |
| 298 | serial->fd = fd; |
| 299 | } |
| 300 | #endif |
| 301 | |
Jeremy Kerr | 597b369 | 2019-09-03 16:24:48 +0800 | [diff] [blame] | 302 | void mctp_serial_set_tx_fn(struct mctp_binding_serial *serial, |
| 303 | mctp_serial_tx_fn fn, void *data) |
| 304 | { |
| 305 | serial->tx_fn = fn; |
| 306 | serial->tx_fn_data = data; |
| 307 | } |
| 308 | |
| 309 | int mctp_serial_rx(struct mctp_binding_serial *serial, |
| 310 | const void *buf, size_t len) |
| 311 | { |
| 312 | mctp_rx_consume(serial, buf, len); |
| 313 | } |
| 314 | |
Jeremy Kerr | 3b36d17 | 2019-09-04 11:56:09 +0800 | [diff] [blame] | 315 | static int mctp_serial_core_start(struct mctp_binding *binding) |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 316 | { |
Jeremy Kerr | 3b36d17 | 2019-09-04 11:56:09 +0800 | [diff] [blame] | 317 | mctp_binding_set_tx_enabled(binding, true); |
| 318 | return 0; |
| 319 | } |
| 320 | |
| 321 | struct mctp_binding *mctp_binding_serial_core(struct mctp_binding_serial *b) |
| 322 | { |
| 323 | return &b->binding; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 324 | } |
| 325 | |
| 326 | struct mctp_binding_serial *mctp_serial_init(void) |
| 327 | { |
| 328 | struct mctp_binding_serial *serial; |
| 329 | |
| 330 | serial = __mctp_alloc(sizeof(*serial)); |
Jeremy Kerr | 0bead57 | 2019-09-02 16:45:33 +0800 | [diff] [blame] | 331 | memset(serial, 0, sizeof(*serial)); |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 332 | serial->fd = -1; |
| 333 | serial->rx_state = STATE_WAIT_SYNC_START; |
| 334 | serial->rx_pkt = NULL; |
| 335 | serial->binding.name = "serial"; |
| 336 | serial->binding.version = 1; |
Jeremy Kerr | df15f7e | 2019-08-05 15:41:19 +0800 | [diff] [blame] | 337 | serial->binding.pkt_size = MCTP_BMTU; |
| 338 | serial->binding.pkt_pad = 0; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 339 | |
Jeremy Kerr | 3b36d17 | 2019-09-04 11:56:09 +0800 | [diff] [blame] | 340 | serial->binding.start = mctp_serial_core_start; |
Jeremy Kerr | 4cdc200 | 2019-02-07 16:49:12 +0800 | [diff] [blame] | 341 | serial->binding.tx = mctp_binding_serial_tx; |
| 342 | |
| 343 | return serial; |
| 344 | } |
| 345 | |