http.c

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