http.c

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