http.c

   1 #include <malloc.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <time.h>
   5
   6 #include "debug.h"
   7 #include "file.h"
   8
   9 #include "http.h"
  10
  11 #define BUFFER_SIZE 128
  12
  13 #define HTTP_VERSION "HTTP/1.0"
  14 #define SERVER_NAME "Webserver/0.0.1"
  15
  16 char *codes[15] = {
  17     "200 OK",
  18     "201 Created",
  19     "202 Accepted",
  20     "204 No Content",
  21     "301 Moved Permanently",
  22     "302 Moved Temporarily",
  23     "304 Not Modified",
  24     "400 Bad Request",
  25     "401 Unauthorized",
  26     "403 Forbidden",
  27     "404 Not Found",
  28     "500 Internal Server Error",
  29     "501 Not Implemented",
  30     "502 Bad Gateway",
  31     "503 Service Unavailable"};
  32
  33 typedef enum {
  34     c200 = 0, c201, c202, c204,
  35     c301, c302, c304, c400,
  36     c401, c403, c404, c500,
  37     c501, c502, c503
  38 } code_t;
  39
  40 typedef enum {
  41     not_supported_e = 0, get_e, head_e, post_e
  42 } method_t;
  43
  44 typedef enum {
  45     encoding_plain_e = 0, encoding_gzip_e, encoding_compress_e
  46 } encoding_t;
  47
  48 typedef struct {
  49     char *allow;
  50     char *authorization;
  51     encoding_t content_encoding;
  52     char *content_length;
  53     char *content_type;
  54     char *date;
  55     char *expires;
  56     char *from;
  57     char *if_modified_since;
  58     char *last_modified;
  59     char *location;
  60     char *pragma;
  61     char *referer;
  62     char *server;
  63     char *user_agent;
  64     char *www_authenticate;
  65 } header_t;
  66
  67 typedef struct {
  68     char *ext;
  69     char *type;
  70     char *charset;
  71 } mime_t;
  72
  73 #define NB_MIMES 8
  74
  75 mime_t mimes[NB_MIMES] = {
  76     {"js", "application/javascript", "iso-8859-1"},
  77     {"css", "text/css", "iso-8859-1"},
  78     {"htm", "text/html", "iso-8859-1"},
  79     {"html", "text/html", "iso-8859-1"},
  80     {"png", "image/png", NULL},
  81     {"jpeg", "image/jpeg", NULL},
  82     {"jpg", "image/jpeg", NULL},
  83     {"txt", "text/plain", "iso-8859-1"}
  84 };
  85
  86 /* find mime type */
  87
  88 mime_t *find_mime_type (char *filename)
  89 {
  90     /* find extention */
  91     char *ext = filename + strlen (filename);
  92     while (--ext > filename) {
  93         if (ext[-1] == '.') {
  94             break;
  95         }
  96     }
  97     if (ext == filename) {
  98         return NULL;
  99     }
 100
 101     /* find mime */
 102     int i;
 103     for (i = 0; i < NB_MIMES; i++) {
 104         if (strcmp (ext, (mimes + i)->ext) == 0) {
 105             return mimes + i;
 106         }
 107     }
 108
 109     return NULL;
 110 }
 111
 112 /* print header values */
 113
 114 void print_header_values (header_t *header)
 115 {
 116     printf ("Header values\n");
 117     if (header->allow) printf ("allow = '%s'\n", header->allow);
 118     if (header->authorization) printf ("authorization = '%s'\n", header->authorization);
 119     if (header->content_encoding) {
 120         printf ("content_encoding = ");
 121         switch (header->content_encoding) {
 122         case encoding_plain_e: printf ("plain\n"); break;
 123         case encoding_gzip_e: printf ("gzip\n"); break;
 124         case encoding_compress_e: printf ("compress\n"); break;
 125         }
 126     }
 127     if (header->content_length) printf ("content_length = '%s'\n", header->content_length);
 128     if (header->content_type) printf ("content_type = '%s'\n", header->content_type);
 129     if (header->date) printf ("date = '%s'\n", header->date);
 130     if (header->expires) printf ("expires = '%s'\n", header->expires);
 131     if (header->from) printf ("from = '%s'\n", header->from);
 132     if (header->if_modified_since) printf ("if_modified_since = '%s'\n", header->if_modified_since);
 133     if (header->last_modified) printf ("last_modified = '%s'\n", header->last_modified);
 134     if (header->location) printf ("location = '%s'\n", header->location);
 135     if (header->pragma) printf ("pragma = '%s'\n", header->pragma);
 136     if (header->referer) printf ("referer = '%s'\n", header->referer);
 137     if (header->server) printf ("server = '%s'\n", header->server);
 138     if (header->user_agent) printf ("user_agent = '%s'\n", header->user_agent);
 139     if (header->www_authenticate) printf ("www_authenticate = '%s'\n", header->www_authenticate);
 140 }
 141
 142 /* find sequence*/
 143
 144 char *find_sequence (char *data, int len, char *seq, char **pdata)
 145 {
 146
 147     int size = strlen (seq);
 148
 149     int i;
 150     for (i = 0; i < len - size + 1; i++) {
 151         if (strncmp (data + i, seq, size) == 0) {
 152             data[i] = 0;
 153             if (pdata != NULL) {
 154                 *pdata = data + i + size;
 155             }
 156             return data;
 157         }
 158     }
 159
 160     return NULL;
 161 }
 162
 163 /* response entity */
 164
 165 int add_line (char **buffer, char *str)
 166 {
 167     VERBOSE (DEBUG, PRINT ("add line: %s\n", str));
 168     int len = ((*buffer) ? strlen (*buffer) : 0) + strlen (str) + 3;
 169     VERBOSE (DEBUG, PRINT ("len: %d\n", len));
 170     if (*buffer) {
 171         *buffer = (char *)realloc (*buffer, len);
 172     } else {
 173         *buffer = (char *)calloc (len, 1);
 174     }
 175     strcat (*buffer, str);
 176     strcat (*buffer, "\r\n");
 177     return len;
 178 }
 179
 180 int add_status_line (char **buffer, code_t code)
 181 {
 182     char tmp[BUFFER_SIZE] = {0};
 183
 184     /* Status */
 185     sprintf (tmp, "%s %s", HTTP_VERSION, codes[code]);
 186     add_line (buffer, tmp);
 187
 188     return strlen (*buffer);
 189 }
 190
 191 int add_general_header (char **buffer)
 192 {
 193     char tmp[BUFFER_SIZE] = {0};
 194
 195     /* Date */
 196     time_t ts = time (NULL);
 197     sprintf (tmp, "Date: %s", ctime (&ts));
 198     tmp[strlen (tmp) - 1] = 0; // remove last \n
 199     add_line (buffer, tmp);
 200
 201     /* Pragma */
 202
 203     return strlen (*buffer);
 204 }
 205
 206 int add_response_header (char **buffer, char *uri)
 207 {
 208     char tmp[BUFFER_SIZE] = {0};
 209
 210     /* Location */
 211     sprintf (tmp, "Location: %s", uri);
 212     add_line (buffer, tmp);
 213
 214     /* Server */
 215     sprintf (tmp, "Server: %s", SERVER_NAME);
 216     add_line (buffer, tmp);
 217
 218     /* WWW-Authentificate */
 219
 220     return strlen (*buffer);
 221 }
 222
 223 int add_entity (char **buffer, char *entity, int size, char *type, char *encoding)
 224 {
 225     char tmp[BUFFER_SIZE] = {0};
 226     int len = strlen (*buffer);
 227
 228     /* Allow */
 229     /* Expires */
 230     /* Last-Modified */
 231
 232     if (entity != NULL) {
 233
 234         /* Content-Encoding */
 235         if (encoding != NULL) {
 236             sprintf (tmp, "Content-Encoding: %s", encoding);
 237             add_line (buffer, tmp);
 238         }
 239
 240         /* Content-Length */
 241         sprintf (tmp, "Content-Length: %d", size);
 242         add_line (buffer, tmp);
 243
 244         /* Content-Type */
 245         sprintf (tmp, "Content-Type: %s", type);
 246         add_line (buffer, tmp);
 247
 248         add_line (buffer, "");
 249
 250         /* Entity */
 251         len = strlen (*buffer);
 252         *buffer = realloc (*buffer, len + size);
 253         memcpy (*buffer + len, entity, size);
 254         len += size;
 255     }
 256
 257     return len;
 258 }
 259
 260 /* error 400 */
 261
 262 int error_400 (char **buffer)
 263 {
 264     add_status_line (buffer, c400);
 265     add_general_header (buffer);
 266     add_response_header (buffer, NULL);
 267
 268     char *response = "<html><head><title>Error 400</title></head><body><p>Bad Request</p></body></html>";
 269     return add_entity (buffer, response, strlen (response), "text/html", "iso-8859-1");
 270 }
 271
 272 /* error 404 */
 273
 274 int error_404 (char **buffer, char *uri)
 275 {
 276     add_status_line (buffer, c404);
 277     add_general_header (buffer);
 278     add_response_header (buffer, uri);
 279
 280     char *response = "<html><head><title>Error 404</title></head><body><p>File not found</p></body></html>";
 281     return add_entity (buffer, response, strlen (response), "text/html", "iso-8859-1");
 282 }
 283
 284 /* generic response */
 285
 286 int generic_response (char **buffer, char *location, char *response, int size)
 287 {
 288     int len = 0;
 289     VERBOSE (DEBUG, PRINT ("add_status_line %d\n", len));
 290     len = add_status_line (buffer, c200);
 291     VERBOSE (DEBUG, PRINT ("add_general_header %d\n", len));
 292     len = add_general_header (buffer);
 293     VERBOSE (DEBUG, PRINT ("add_response_header %d\n", len));
 294     len = add_response_header (buffer, location);
 295     mime_t *mime = find_mime_type (location);
 296
 297     VERBOSE (DEBUG, PRINT ("add_entity %d\n", len));
 298     return add_entity (buffer, response, size, mime->type, mime->charset);
 299 }
 300
 301 /* trim string */
 302
 303 char *trim (char *str)
 304 {
 305     if (str != NULL) {
 306         while ((*str == ' ') || (*str == '\t')) {
 307             str++;
 308         }
 309     }
 310     return str;
 311 }
 312
 313 /* main HTTP processing */
 314
 315 int processing (char *data, int len, conf_t *conf, char **pdata)
 316 {
 317     char *saved_data = data;
 318     char location[BUFFER_SIZE] = {0};
 319     VERBOSE (DEBUG, PRINT ("Start processing\n"));
 320
 321     /* check method */
 322     char *line = find_sequence (data, len + data - saved_data, "\r\n", &data);
 323     if (line == NULL) {
 324         VERBOSE (WARNING, PRINT ("Unknown received data\n"));
 325         if (pdata != NULL) {
 326             *pdata = NULL;
 327         }
 328         return 0;
 329     }
 330     VERBOSE (DEBUG, PRINT ("Command line: '%s'\n", line));
 331
 332     char *method = strtok (line, " ");
 333     char *uri = strtok (NULL, " ");
 334     char *version = strtok (NULL, " ");
 335     method_t type = not_supported_e;
 336     if (strcmp (method, "GET") == 0) {
 337         type = get_e;
 338     } else if (strcmp ("HEAD", method) == 0) {
 339         type = head_e;
 340     } else if (strcmp ("POST", method) == 0) {
 341         type = post_e;
 342     } else {
 343         VERBOSE (WARNING, PRINT ("Unkown method: %s\n", method));
 344         return error_400 (pdata);
 345     }
 346     VERBOSE (INFO, PRINT ("%s %s (%s)\n", (type == get_e) ? "Get" : (type == head_e) ? "Head" : "Post", uri, version));
 347
 348     /* analyse uri */
 349     char *filename = strtok (uri, "&");
 350     char *variables = strtok (NULL, "\n");
 351     char *path = (char *) calloc (strlen (conf->root) + strlen (filename) + 2, 1);
 352     //sprintf (filename, "%s%s%s", conf->root, ((conf->root[strlen (conf->root) - 1] != '/') && (uri[0] != '/')) ? "/" : "", uri);
 353     sprintf (path, "%s/%s", conf->root, filename);
 354
 355     /* check header */
 356     header_t header = {0};
 357     while (strcmp (line = find_sequence (data, len + data - saved_data, "\r\n", &data), "") != 0) {
 358         VERBOSE (DEBUG, PRINT ("Header line: '%s'\n", line));
 359         char *field = strtok (line, ":");
 360         char *value = trim (strtok (NULL, "\r"));
 361         VERBOSE (DEBUG, PRINT ("Field: %s\nValue: %s\n", field, value));
 362         if (*line == 0) {
 363             break;
 364         }
 365
 366         VERBOSE (DEBUG, PRINT ("Analyse field\n"));
 367         if (strcmp (field, "Allow") == 0) { header.allow = value; }
 368         else if (strcmp (field, "Authorization") == 0) { header.authorization = value; }
 369         else if (strcmp (field, "Content-Encoding") == 0) {
 370             if (strcmp (value, "x-gzip") == 0) {
 371                 header.content_encoding = encoding_gzip_e;
 372             } else if (strcmp (value, "x-compress") == 0) {
 373                 header.content_encoding = encoding_compress_e;
 374             } else {
 375                 VERBOSE (WARNING, PRINT ("Unknown content encoding: %s\n", value));
 376             }
 377         } else if (strcmp (field, "Content-Length") == 0) { header.content_length = value; }
 378         else if (strcmp (field, "Content-Type") == 0) { header.content_type = value; }
 379         else if (strcmp (field, "Date") == 0) { header.date = value; }
 380         else if (strcmp (field, "Expires") == 0) { header.expires = value; }
 381         else if (strcmp (field, "From") == 0) { header.from = value; }
 382         else if (strcmp (field, "If-Modified-Since") == 0) { header.if_modified_since = value; }
 383         else if (strcmp (field, "Last-Modified") == 0) { header.last_modified = value; }
 384         else if (strcmp (field, "Location") == 0) { header.location = value; }
 385         else if (strcmp (field, "Pragma") == 0) { header.pragma = value; }
 386         else if (strcmp (field, "Referer") == 0) { header.referer = value; }
 387         else if (strcmp (field, "Server") == 0) { header.server = value; }
 388         else if (strcmp (field, "User-Agent") == 0) { header.user_agent = value; }
 389         else if (strcmp (field, "WWW-Authenticate") == 0) { header.www_authenticate = value; }
 390         else { VERBOSE (WARNING, PRINT ("Unknown header field: '%s'\n", field)); }
 391     }
 392     VERBOSE (DEBUG, print_header_values (&header));
 393
 394     /* body */
 395     char *body = data;
 396     len -= saved_data - data;
 397     if (len != (header.content_length ? atoi (header.content_length) : 0)) {
 398         VERBOSE (WARNING, PRINT ("Incoherent size (%d <> %s)\n", len, header.content_length));
 399     }
 400     if (len > 0) {
 401         switch (header.content_encoding) {
 402         case encoding_plain_e: break;
 403         case encoding_gzip_e: VERBOSE (WARNING, PRINT ("Gzip encoding not supported yet\n")); break;
 404         case encoding_compress_e: VERBOSE (WARNING, PRINT ("Compress encoding not supported yet\n")); break;
 405         }
 406     }
 407
 408     /* response */
 409     char *buffer = NULL;
 410     FILE *fid = NULL;
 411     switch (type) {
 412     case get_e:
 413     case post_e: /* fall through */
 414         VERBOSE (DEBUG, PRINT ("Read file %s\n", path));
 415         len = readfile (&buffer, path);
 416         if (len < 0) {
 417             sprintf (location, "http://%s/", conf->servername);
 418             len = error_404 (pdata, location);
 419         } else {
 420             sprintf (location, "http://%s%s", conf->servername, path);
 421             len = generic_response (pdata, location, buffer, len);
 422             free (buffer);
 423         }
 424         break;
 425     case head_e:
 426         VERBOSE (DEBUG, PRINT ("Test file %s\n", path));
 427         fid = fopen (path, "rb");
 428         if (fid == NULL) {
 429             sprintf (location, "http://%s/", conf->servername);
 430             len = error_404 (pdata, location);
 431         } else {
 432             fclose (fid);
 433             sprintf (location, "http://%s%s", conf->servername, path);
 434             len = generic_response (pdata, location, NULL, 0);
 435         }
 436         break;
 437     case not_supported_e:
 438         break;
 439     }
 440
 441     /* cleaning */
 442     VERBOSE (DEBUG, PRINT ("Cleaning\n"));
 443     if (path) {
 444         VERBOSE (DEBUG, PRINT ("Cleaning path\n"));
 445         free (path);
 446     }
 447
 448     return len;
 449 }
 450
 451 /* vim: set ts=4 sw=4 et: */