adamdunkels | d0791bb | 2005-02-22 22:23:07 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2004, Swedish Institute of Computer Science. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 3. Neither the name of the Institute nor the names of its contributors |
| 14 | * may be used to endorse or promote products derived from this software |
| 15 | * without specific prior written permission. |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE |
| 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. |
| 28 | * |
| 29 | * This file is part of the Contiki operating system. |
| 30 | * |
| 31 | * Author: Adam Dunkels <adam@sics.se> |
| 32 | * |
| 33 | * $Id: psock.h,v 1.1 2005/02/22 22:23:07 adamdunkels Exp $ |
| 34 | */ |
| 35 | |
| 36 | /** |
| 37 | * \defgroup psock Protosockets library |
| 38 | * @{ |
| 39 | * |
| 40 | * The protosocket library provides an interface to the uIP stack that is |
| 41 | * similar to the traditional BSD socket interface. Unlike programs |
| 42 | * written for the ordinary uIP event-driven interface, programs |
| 43 | * written with the protosocket library are executed in a sequential |
| 44 | * fashion and does not have to be implemented as explicit state |
| 45 | * machines. |
| 46 | * |
| 47 | * Protosockets only work with TCP connections. |
| 48 | * |
| 49 | * The protosocket library uses \ref pt protothreads to provide |
| 50 | * sequential control flow. This makes the protosockets lightweight in |
| 51 | * terms of memory, but also means that protosockets inherits the |
| 52 | * functional limitations of protothreads. Each protosocket lives only |
| 53 | * within a single function block. Automatic variables (stack |
| 54 | * variables) are not necessarily retained across a protosocket |
| 55 | * library function call. |
| 56 | * |
| 57 | * \note Because the protosocket library uses protothreads, local variables |
| 58 | * will not always be saved across a call to a protosocket library |
| 59 | * function. It is therefore advised that local variables are used |
| 60 | * with extreme care. |
| 61 | * |
| 62 | * The protosocket library provides functions for sending data without |
| 63 | * having to deal with retransmissions and acknowledgements, as well |
| 64 | * as functions for reading data without having to deal with data |
| 65 | * being split across more than one TCP segment. |
| 66 | * |
| 67 | * Because each protosocket runs as a protothread, the protosocket has to be |
| 68 | * started with a call to PSOCK_BEGIN() at the start of the function |
| 69 | * in which the protosocket is used. Similarly, the protosocket protothread can |
| 70 | * be terminated by a call to PSOCK_EXIT(). |
| 71 | * |
| 72 | * The example code below illustrates how to use the protosocket |
| 73 | * library. The program implements a simple SMTP client that sends a |
| 74 | * short email. The program is divided into two functions, one uIP |
| 75 | * event handler (smtp_uipcall()) and one function that runs the |
| 76 | * protosocket protothread and performs the SMTP communication |
| 77 | * (smtp_socketthread()). |
| 78 | * |
| 79 | * An SMTP connection is represented by a smtp_state structure |
| 80 | * containing a struct psock and a small input buffer. The input |
| 81 | * buffer only needs to be 3 bytes long to accomodate the 3 byte |
| 82 | * status codes used by SMTP. Connection structures can be allocated |
| 83 | * from the memory buffer called connections, which is declared with |
| 84 | * the MEMB() macro. |
| 85 | * |
| 86 | * The convenience macro SEND_STRING() is defined in order to simplify |
| 87 | * the code, as it mostly involves sending strings. |
| 88 | * |
| 89 | * The function smtp_socketthread() is declared as a protothread using |
| 90 | * the PT_THREAD() macro. The PSOCK_BEGIN() call at the first line of |
| 91 | * the smtp_socketthread() function starts the protothread. SMTP |
| 92 | * specifies that the server will start with sending a welcome message |
| 93 | * that should include the status code 220 if the server is ready to |
| 94 | * accept messages. Therefore, the smtp_socketthread() first calls |
| 95 | * PSOCK_READTO() to read all incoming data up to the first |
| 96 | * newline. If the status code was anything else but 220, the protosocket |
| 97 | * is closed and the protosocket's protothread is terminated with the call |
| 98 | * to PSOCK_CLOSE_EXIT(). |
| 99 | * |
| 100 | * If the connection is accepted by the server, smtp_socketthread() |
| 101 | * continues with sending the HELO message. If this gets a positive |
| 102 | * reply (a status code beginning with a 2), the protothread moves on |
| 103 | * with the rest of the SMTP procedure. Finally, after all headers and |
| 104 | * data is sent, the program sends a QUIT before it finally closes the |
| 105 | * protosocket and exits the protosocket's protothread. |
| 106 | * |
| 107 | * |
| 108 | \code |
| 109 | #include <string.h> |
| 110 | |
| 111 | #include "psock.h" |
| 112 | #include "memb.h" |
| 113 | |
| 114 | struct smtp_state { |
| 115 | struct psock psock; |
| 116 | char inputbuffer[3]; |
| 117 | }; |
| 118 | |
| 119 | MEMB(connections, sizeof(struct smtp_state), 2); |
| 120 | |
| 121 | #define SEND_STRING(s, str) PSOCK_SEND(s, str, strlen(str)) |
| 122 | |
| 123 | static |
| 124 | PT_THREAD(smtp_socketthread(struct smtp_state *s)) |
| 125 | { |
| 126 | PSOCK_BEGIN(&s->psock); |
| 127 | |
| 128 | PSOCK_READTO(&s->psock, '\n'); |
| 129 | |
| 130 | if(strncmp(s->inputbuffer, "220", 3) != 0) { |
| 131 | PSOCK_CLOSE_EXIT(&s->psock); |
| 132 | } |
| 133 | |
| 134 | SEND_STRING(&s->psock, "HELO contiki.example.com\r\n"); |
| 135 | |
| 136 | PSOCK_READTO(&s->psock, '\n'); |
| 137 | if(s->inputbuffer[0] != '2') { |
| 138 | PSOCK_CLOSE_EXIT(&s->psock); |
| 139 | } |
| 140 | |
| 141 | SEND_STRING(&s->psock, "MAIL FROM: contiki@example.com\r\n"); |
| 142 | |
| 143 | PSOCK_READTO(&s->psock, '\n'); |
| 144 | if(s->inputbuffer[0] != '2') { |
| 145 | PSOCK_CLOSE_EXIT(&s->psock); |
| 146 | } |
| 147 | |
| 148 | SEND_STRING(&s->psock, "RCPT TO: contiki@example.com\r\n"); |
| 149 | |
| 150 | PSOCK_READTO(&s->psock, '\n'); |
| 151 | if(s->inputbuffer[0] != '2') { |
| 152 | PSOCK_CLOSE_EXIT(&s->psock); |
| 153 | } |
| 154 | |
| 155 | SEND_STRING(&s->psock, "DATA\r\n"); |
| 156 | |
| 157 | PSOCK_READTO(&s->psock, '\n'); |
| 158 | if(s->inputbuffer[0] != '3') { |
| 159 | PSOCK_CLOSE_EXIT(&s->psock); |
| 160 | } |
| 161 | |
| 162 | SEND_STRING(&s->psock, "To: contiki@example.com\r\n"); |
| 163 | SEND_STRING(&s->psock, "From: contiki@example.com\r\n"); |
| 164 | SEND_STRING(&s->psock, "Subject: Example\r\n"); |
| 165 | |
| 166 | SEND_STRING(&s->psock, "A test message from Contiki.\r\n"); |
| 167 | |
| 168 | SEND_STRING(&s->psock, "\r\n.\r\n"); |
| 169 | |
| 170 | PSOCK_READTO(&s->psock, '\n'); |
| 171 | if(s->inputbuffer[0] != '2') { |
| 172 | PSOCK_CLOSE_EXIT(&s->psock); |
| 173 | } |
| 174 | |
| 175 | SEND_STRING(&s->psock, "QUIT\r\n"); |
| 176 | |
| 177 | PSOCK_END(&s->psock); |
| 178 | } |
| 179 | |
| 180 | void |
| 181 | smtp_uipcall(void *state) |
| 182 | { |
| 183 | struct smtp_state *s = (struct smtp_state *)state; |
| 184 | |
| 185 | if(uip_closed() || uip_aborted() || uip_timedout()) { |
| 186 | memb_free(&connections, s); |
| 187 | } else if(uip_connected()) { |
| 188 | PSOCK_INIT(s, s->inputbuffer, sizeof(s->inputbuffer)); |
| 189 | } else { |
| 190 | smtp_socketthread(s); |
| 191 | } |
| 192 | } |
| 193 | \endcode |
| 194 | * |
| 195 | */ |
| 196 | |
| 197 | /** |
| 198 | * \file |
| 199 | * Protosocket library header file |
| 200 | * \author |
| 201 | * Adam Dunkels <adam@sics.se> |
| 202 | * |
| 203 | */ |
| 204 | |
| 205 | #ifndef __PSOCK_H__ |
| 206 | #define __PSOCK_H__ |
| 207 | |
| 208 | #include "pt.h" |
| 209 | #include "uipbuf.h" |
| 210 | #include "memb.h" |
| 211 | |
| 212 | /** |
| 213 | * The representation of a protosocket. |
| 214 | * |
| 215 | * The protosocket structrure is an opaque structure with no user-visible |
| 216 | * elements. |
| 217 | */ |
| 218 | struct psock { |
| 219 | struct pt pt, psockpt; |
| 220 | unsigned char state; |
| 221 | const u8_t *sendptr; |
| 222 | u16_t sendlen; |
| 223 | u8_t *readptr; |
| 224 | u16_t readlen; |
| 225 | |
| 226 | struct uipbuf_buffer buf; |
| 227 | char *bufptr; |
| 228 | unsigned int bufsize; |
| 229 | }; |
| 230 | |
| 231 | void psock_init(struct psock *psock, char *buffer, unsigned int buffersize); |
| 232 | /** |
| 233 | * Initialize a protosocket. |
| 234 | * |
| 235 | * This macro initializes a protosocket and must be called before the |
| 236 | * protosocket is used. The initialization also specifies the input buffer |
| 237 | * for the protosocket. |
| 238 | * |
| 239 | * \param psock (struct psock *) A pointer to the protosocket to be |
| 240 | * initialized |
| 241 | * |
| 242 | * \param buffer (char *) A pointer to the input buffer for the |
| 243 | * protosocket. |
| 244 | * |
| 245 | * \param buffersize (unsigned int) The size of the input buffer. |
| 246 | * |
| 247 | * \hideinitializer |
| 248 | */ |
| 249 | #define PSOCK_INIT(psock, buffer, buffersize) \ |
| 250 | psock_init(psock, buffer, buffersize) |
| 251 | |
| 252 | /** |
| 253 | * Start the protosocket protothread in a function. |
| 254 | * |
| 255 | * This macro starts the protothread associated with the protosocket and |
| 256 | * must come before other protosocket calls in the function it is used. |
| 257 | * |
| 258 | * \param psock (struct psock *) A pointer to the protosocket to be |
| 259 | * started. |
| 260 | * |
| 261 | * \hideinitializer |
| 262 | */ |
| 263 | #define PSOCK_BEGIN(psock) PT_BEGIN(&((psock)->pt)) |
| 264 | |
| 265 | PT_THREAD(psock_send(struct psock *psock, const char *buf, unsigned int len)); |
| 266 | /** |
| 267 | * Send data. |
| 268 | * |
| 269 | * This macro sends data over a protosocket. The protosocket protothread blocks |
| 270 | * until all data has been sent and is known to have been received by |
| 271 | * the remote end of the TCP connection. |
| 272 | * |
| 273 | * \param psock (struct psock *) A pointer to the protosocket over which |
| 274 | * data is to be sent. |
| 275 | * |
| 276 | * \param data (char *) A pointer to the data that is to be sent. |
| 277 | * |
| 278 | * \param datalen (unsigned int) The length of the data that is to be |
| 279 | * sent. |
| 280 | * |
| 281 | * \hideinitializer |
| 282 | */ |
| 283 | #define PSOCK_SEND(psock, data, datalen) \ |
| 284 | PT_WAIT_THREAD(&((psock)->pt), psock_send(psock, data, datalen)) |
| 285 | |
| 286 | PT_THREAD(psock_generator_send(struct psock *psock, |
| 287 | unsigned short (*f)(void *), void *arg)); |
| 288 | |
| 289 | #define PSOCK_GENERATOR_SEND(psock, generator, arg) \ |
| 290 | PT_WAIT_THREAD(&((psock)->pt), \ |
| 291 | psock_generator_send(psock, generator, arg)) |
| 292 | |
| 293 | |
| 294 | /*PT_THREAD(psock_closew(struct psock *psock)); |
| 295 | #define PSOCK_CLOSEW(psock) \ |
| 296 | PT_WAIT_THREAD(&(psock)->pt, psock_closew(psock)) |
| 297 | */ |
| 298 | |
| 299 | /** |
| 300 | * Close a protosocket. |
| 301 | * |
| 302 | * This macro closes a protosocket and can only be called from within the |
| 303 | * protothread in which the protosocket lives. |
| 304 | * |
| 305 | * \param psock (struct psock *) A pointer to the protosocket that is to |
| 306 | * be closed. |
| 307 | * |
| 308 | * \hideinitializer |
| 309 | */ |
| 310 | #define PSOCK_CLOSE(psock) uip_close() |
| 311 | |
| 312 | PT_THREAD(psock_readto(struct psock *psock, unsigned char c)); |
| 313 | |
| 314 | /** |
| 315 | * Read data up to a specified character. |
| 316 | * |
| 317 | * This macro will block waiting for data and read the data into the |
| 318 | * input buffer specified with the call to PSOCK_INIT(). Data is only |
| 319 | * read until the specifieed character appears in the data stream. |
| 320 | * |
| 321 | * \param psock (struct psock *) A pointer to the protosocket from which |
| 322 | * data should be read. |
| 323 | * |
| 324 | * \param c (char) The character at which to stop reading. |
| 325 | * |
| 326 | * \hideinitializer |
| 327 | */ |
| 328 | #define PSOCK_READTO(psock, c) \ |
| 329 | PT_WAIT_THREAD(&((psock)->pt), psock_readto(psock, c)) |
| 330 | |
| 331 | /** |
| 332 | * The length of the data that was previously read. |
| 333 | * |
| 334 | * This macro returns the length of the data that was previously read |
| 335 | * using PSOCK_READTO() or PSOCK_READ(). |
| 336 | * |
| 337 | * \param psock (struct psock *) A pointer to the protosocket holding the data. |
| 338 | * |
| 339 | * \hideinitializer |
| 340 | */ |
| 341 | #define PSOCK_DATALEN(psock) uipbuf_len(&(psock)->buf) |
| 342 | |
| 343 | /** |
| 344 | * Exit the protosocket's protothread. |
| 345 | * |
| 346 | * This macro terminates the protothread of the protosocket and should |
| 347 | * almost always be used in conjunction with PSOCK_CLOSE(). |
| 348 | * |
| 349 | * \sa PSOCK_CLOSE_EXIT() |
| 350 | * |
| 351 | * \param psock (struct psock *) A pointer to the protosocket. |
| 352 | * |
| 353 | * \hideinitializer |
| 354 | */ |
| 355 | #define PSOCK_EXIT(psock) PT_EXIT(&((psock)->pt)) |
| 356 | |
| 357 | /** |
| 358 | * Close a protosocket and exit the protosocket's protothread. |
| 359 | * |
| 360 | * This macro closes a protosocket and exits the protosocket's protothread. |
| 361 | * |
| 362 | * \param psock (struct psock *) A pointer to the protosocket. |
| 363 | * |
| 364 | * \hideinitializer |
| 365 | */ |
| 366 | #define PSOCK_CLOSE_EXIT(psock) \ |
| 367 | do { \ |
| 368 | PSOCK_CLOSE(psock); \ |
| 369 | PSOCK_EXIT(psock); \ |
| 370 | } while(0) |
| 371 | |
| 372 | #define PSOCK_END(psock) PT_END(&((psock)->pt)) |
| 373 | |
| 374 | char psock_newdata(struct psock *s); |
| 375 | |
| 376 | /** |
| 377 | * Check if new data has arrived on a protosocket. |
| 378 | * |
| 379 | * This macro is used in conjunction with the PSOCK_WAIT_UNTIL() |
| 380 | * macro to check if data has arrived on a protosocket. |
| 381 | * |
| 382 | * \param psock (struct psock *) A pointer to the protosocket. |
| 383 | * |
| 384 | * \hideinitializer |
| 385 | */ |
| 386 | #define PSOCK_NEWDATA(psock) psock_newdata(psock) |
| 387 | |
| 388 | /** |
| 389 | * Wait until a condition is true. |
| 390 | * |
| 391 | * This macro blocks the protothread until the specified condition is |
| 392 | * true. The macro PSOCK_NEWDATA() can be used to check if new data |
| 393 | * arrives when the protosocket is waiting. |
| 394 | * |
| 395 | * Typically, this macro is used as follows: |
| 396 | * |
| 397 | \code |
| 398 | PT_THREAD(thread(struct psock *s, struct timer *t)) |
| 399 | { |
| 400 | PSOCK_BEGIN(s); |
| 401 | |
| 402 | PSOCK_WAIT_UNTIL(s, PSOCK_NEWADATA(s) || timer_expired(t)); |
| 403 | |
| 404 | if(PSOCK_NEWDATA(s)) { |
| 405 | PSOCK_READTO(s, '\n'); |
| 406 | } else { |
| 407 | handle_timed_out(s); |
| 408 | } |
| 409 | |
| 410 | PSOCK_END(s); |
| 411 | } |
| 412 | \endcode |
| 413 | * |
| 414 | * \param psock (struct psock *) A pointer to the protosocket. |
| 415 | * \param condition The condition to wait for. |
| 416 | * |
| 417 | * \hideinitializer |
| 418 | */ |
| 419 | #define PSOCK_WAIT_UNTIL(psock, condition) \ |
| 420 | PT_WAIT_UNTIL(&((psock)->pt), (condition)); |
| 421 | |
| 422 | #define PSOCK_WAIT_THREAD(psock, condition) \ |
| 423 | PT_WAIT_THREAD(&((psock)->pt), (condition)) |
| 424 | |
| 425 | #endif /* __PSOCK_H__ */ |