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