3 * UCC (University [of WA] Computer Club) Electronic Accounting System
5 * server.c - Client Server Code
7 * This file is licenced under the 3-clause BSD Licence. See the file
8 * COPYING for full details.
13 #include <sys/socket.h>
14 #include <netinet/in.h>
15 #include <arpa/inet.h>
20 #define HACK_TPG_NOAUTH 1
21 #define HACK_ROOT_NOAUTH 1
24 #define MAX_CONNECTION_QUEUE 5
25 #define INPUT_BUFFER_SIZE 256
27 #define HASH_TYPE SHA1
28 #define HASH_LENGTH 20
30 #define MSG_STR_TOO_LONG "499 Command too long (limit "EXPSTR(INPUT_BUFFER_SIZE)")\n"
33 typedef struct sClient
37 int bIsTrusted; // Is the connection from a trusted host/port
47 void Server_Start(void);
48 void Server_Cleanup(void);
49 void Server_HandleClient(int Socket, int bTrusted);
50 char *Server_ParseClientCommand(tClient *Client, char *CommandString);
52 char *Server_Cmd_USER(tClient *Client, char *Args);
53 char *Server_Cmd_PASS(tClient *Client, char *Args);
54 char *Server_Cmd_AUTOAUTH(tClient *Client, char *Args);
55 char *Server_Cmd_ENUMITEMS(tClient *Client, char *Args);
56 char *Server_Cmd_ITEMINFO(tClient *Client, char *Args);
57 char *Server_Cmd_DISPENSE(tClient *Client, char *Args);
59 int GetUserAuth(const char *Salt, const char *Username, const uint8_t *Hash);
60 void HexBin(uint8_t *Dest, char *Src, int BufSize);
63 int giServer_Port = 1020;
64 int giServer_NextClientID = 1;
66 struct sClientCommand {
68 char *(*Function)(tClient *Client, char *Arguments);
69 } gaServer_Commands[] = {
70 {"USER", Server_Cmd_USER},
71 {"PASS", Server_Cmd_PASS},
72 {"AUTOAUTH", Server_Cmd_AUTOAUTH},
73 {"ENUM_ITEMS", Server_Cmd_ENUMITEMS},
74 {"ITEM_INFO", Server_Cmd_ITEMINFO},
75 {"DISPENSE", Server_Cmd_DISPENSE}
77 #define NUM_COMMANDS (sizeof(gaServer_Commands)/sizeof(gaServer_Commands[0]))
82 * \brief Open listenting socket and serve connections
84 void Server_Start(void)
87 struct sockaddr_in server_addr, client_addr;
89 atexit(Server_Cleanup);
92 giServer_Socket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
93 if( giServer_Socket < 0 ) {
94 fprintf(stderr, "ERROR: Unable to create server socket\n");
98 // Make listen address
99 memset(&server_addr, 0, sizeof(server_addr));
100 server_addr.sin_family = AF_INET; // Internet Socket
101 server_addr.sin_addr.s_addr = htonl(INADDR_ANY); // Listen on all interfaces
102 server_addr.sin_port = htons(giServer_Port); // Port
105 if( bind(giServer_Socket, (struct sockaddr *) &server_addr, sizeof(server_addr)) < 0 ) {
106 fprintf(stderr, "ERROR: Unable to bind to 0.0.0.0:%i\n", giServer_Port);
112 if( listen(giServer_Socket, MAX_CONNECTION_QUEUE) < 0 ) {
113 fprintf(stderr, "ERROR: Unable to listen to socket\n");
118 printf("Listening on 0.0.0.0:%i\n", giServer_Port);
122 uint len = sizeof(client_addr);
125 client_socket = accept(giServer_Socket, (struct sockaddr *) &client_addr, &len);
126 if(client_socket < 0) {
127 fprintf(stderr, "ERROR: Unable to accept client connection\n");
131 if(giDebugLevel >= 2) {
132 char ipstr[INET_ADDRSTRLEN];
133 inet_ntop(AF_INET, &client_addr.sin_addr, ipstr, INET_ADDRSTRLEN);
134 printf("Client connection from %s:%i\n",
135 ipstr, ntohs(client_addr.sin_port));
138 // Trusted Connections
139 if( ntohs(client_addr.sin_port) < 1024 )
141 // TODO: Make this runtime configurable
142 switch( ntohl( client_addr.sin_addr.s_addr ) )
144 case 0x7F000001: // 127.0.0.1 localhost
145 //case 0x825E0D00: // 130.95.13.0
146 case 0x825E0D12: // 130.95.13.18 mussel
147 case 0x825E0D17: // 130.95.13.23 martello
155 // TODO: Multithread this?
156 Server_HandleClient(client_socket, bTrusted);
158 close(client_socket);
162 void Server_Cleanup(void)
164 printf("Close(%i)\n", giServer_Socket);
165 close(giServer_Socket);
169 * \brief Reads from a client socket and parses the command strings
170 * \param Socket Client socket number/handle
171 * \param bTrusted Is the client trusted?
173 void Server_HandleClient(int Socket, int bTrusted)
175 char inbuf[INPUT_BUFFER_SIZE];
177 int remspace = INPUT_BUFFER_SIZE-1;
179 tClient clientInfo = {0};
181 // Initialise Client info
182 clientInfo.ID = giServer_NextClientID ++;
183 clientInfo.bIsTrusted = bTrusted;
188 * - The `buf` and `remspace` variables allow a line to span several
189 * calls to recv(), if a line is not completed in one recv() call
190 * it is saved to the beginning of `inbuf` and `buf` is updated to
193 while( (bytes = recv(Socket, buf, remspace, 0)) > 0 )
196 buf[bytes] = '\0'; // Allow us to use stdlib string functions on it
200 while( (eol = strchr(start, '\n')) )
204 ret = Server_ParseClientCommand(&clientInfo, start);
205 // `ret` is a string on the heap
206 send(Socket, ret, strlen(ret), 0);
211 // Check if there was an incomplete line
212 if( *start != '\0' ) {
213 int tailBytes = bytes - (start-buf);
214 // Roll back in buffer
215 memcpy(inbuf, start, tailBytes);
216 remspace -= tailBytes;
218 send(Socket, MSG_STR_TOO_LONG, sizeof(MSG_STR_TOO_LONG), 0);
220 remspace = INPUT_BUFFER_SIZE - 1;
225 remspace = INPUT_BUFFER_SIZE - 1;
231 fprintf(stderr, "ERROR: Unable to recieve from client on socket %i\n", Socket);
235 if(giDebugLevel >= 2) {
236 printf("Client %i: Disconnected\n", clientInfo.ID);
241 * \brief Parses a client command and calls the required helper function
242 * \param Client Pointer to client state structure
243 * \param CommandString Command from client (single line of the command)
244 * \return Heap String to return to the client
246 char *Server_ParseClientCommand(tClient *Client, char *CommandString)
251 // Split at first space
252 space = strchr(CommandString, ' ');
262 for( i = 0; i < NUM_COMMANDS; i++ )
264 if(strcmp(CommandString, gaServer_Commands[i].Name) == 0)
265 return gaServer_Commands[i].Function(Client, args);
268 return strdup("400 Unknown Command\n");
275 * \brief Set client username
277 * Usage: USER <username>
279 char *Server_Cmd_USER(tClient *Client, char *Args)
285 printf("Client %i authenticating as '%s'\n", Client->ID, Args);
289 free(Client->Username);
290 Client->Username = strdup(Args);
293 // Create a salt (that changes if the username is changed)
294 // Yes, I know, I'm a little paranoid, but who isn't?
295 Client->Salt[0] = 0x21 + (rand()&0x3F);
296 Client->Salt[1] = 0x21 + (rand()&0x3F);
297 Client->Salt[2] = 0x21 + (rand()&0x3F);
298 Client->Salt[3] = 0x21 + (rand()&0x3F);
299 Client->Salt[4] = 0x21 + (rand()&0x3F);
300 Client->Salt[5] = 0x21 + (rand()&0x3F);
301 Client->Salt[6] = 0x21 + (rand()&0x3F);
302 Client->Salt[7] = 0x21 + (rand()&0x3F);
304 // TODO: Also send hash type to use, (SHA1 or crypt according to [DAA])
305 // "100 Salt xxxxXXXX\n"
306 ret = strdup("100 SALT xxxxXXXX\n");
307 sprintf(ret, "100 SALT %s\n", Client->Salt);
309 ret = strdup("100 User Set\n");
315 * \brief Authenticate as a user
319 char *Server_Cmd_PASS(tClient *Client, char *Args)
321 uint8_t clienthash[HASH_LENGTH] = {0};
324 HexBin(clienthash, Args, HASH_LENGTH);
326 // TODO: Decrypt password passed
328 Client->UID = GetUserAuth(Client->Salt, Client->Username, clienthash);
330 if( Client->UID != -1 ) {
331 Client->bIsAuthed = 1;
332 return strdup("200 Auth OK\n");
337 printf("Client %i: Password hash ", Client->ID);
338 for(i=0;i<HASH_LENGTH;i++)
339 printf("%02x", clienthash[i]&0xFF);
343 return strdup("401 Auth Failure\n");
347 * \brief Authenticate as a user without a password
349 * Usage: AUTOAUTH <user>
351 char *Server_Cmd_AUTOAUTH(tClient *Client, char *Args)
353 char *spos = strchr(Args, ' ');
354 if(spos) *spos = '\0'; // Remove characters after the ' '
357 if( !Client->bIsTrusted ) {
359 printf("Client %i: Untrusted client attempting to AUTOAUTH\n", Client->ID);
360 return strdup("401 Untrusted\n");
364 Client->UID = GetUserID( Args );
365 if( Client->UID < 0 ) {
367 printf("Client %i: Unknown user '%s'\n", Client->ID, Args);
368 return strdup("401 Auth Failure\n");
372 printf("Client %i: Authenticated as '%s' (%i)\n", Client->ID, Args, Client->UID);
374 return strdup("200 Auth OK\n");
378 * \brief Enumerate the items that the server knows about
380 char *Server_Cmd_ENUMITEMS(tClient *Client, char *Args)
382 // int nItems = giNumItems;
387 retLen = snprintf(NULL, 0, "201 Items %i", giNumItems);
389 for( i = 0; i < giNumItems; i ++ )
391 retLen += snprintf(NULL, 0, " %s:%i", gaItems[i].Handler->Name, gaItems[i].ID);
394 ret = malloc(retLen+1);
396 retLen += sprintf(ret+retLen, "201 Items %i", giNumItems);
398 for( i = 0; i < giNumItems; i ++ ) {
399 retLen += sprintf(ret+retLen, " %s:%i", gaItems[i].Handler->Name, gaItems[i].ID);
407 tItem *_GetItemFromString(char *String)
411 char *colon = strchr(String, ':');
423 for( i = 0; i < giNumHandlers; i ++ )
425 if( strcmp(gaHandlers[i]->Name, type) == 0) {
426 handler = gaHandlers[i];
435 for( i = 0; i < giNumItems; i ++ )
437 if( gaItems[i].Handler != handler ) continue;
438 if( gaItems[i].ID != num ) continue;
445 * \brief Fetch information on a specific item
447 char *Server_Cmd_ITEMINFO(tClient *Client, char *Args)
451 tItem *item = _GetItemFromString(Args);
454 return strdup("406 Bad Item ID\n");
458 retLen = snprintf(NULL, 0, "202 Item %s:%i %i %s\n",
459 item->Handler->Name, item->ID, item->Price, item->Name);
460 ret = malloc(retLen+1);
461 sprintf(ret, "202 Item %s:%i %i %s\n",
462 item->Handler->Name, item->ID, item->Price, item->Name);
467 char *Server_Cmd_DISPENSE(tClient *Client, char *Args)
471 if( !Client->bIsAuthed ) return strdup("401 Not Authenticated\n");
473 item = _GetItemFromString(Args);
475 return strdup("406 Bad Item ID\n");
478 switch( ret = DispenseItem( Client->UID, item ) )
480 case 0: return strdup("200 Dispense OK\n");
481 case 1: return strdup("501 Unable to dispense\n");
482 case 2: return strdup("402 Poor You\n");
484 return strdup("500 Dispense Error\n");
488 char *Server_Cmd_GIVE(tClient *Client, char *Args)
490 char *recipient, *ammount, *reason;
493 if( !Client->bIsAuthed ) return strdup("401 Not Authenticated\n");
497 ammount = strchr(Args, ' ');
498 if( !ammount ) return strdup("407 Invalid Argument, expected 3 parameters, 1 encountered\n");
502 reason = strchr(ammount, ' ');
503 if( !reason ) return strdup("407 Invalid Argument, expected 3 parameters, 2 encountered\n");
508 uid = GetUserID(recipient);
509 if( uid == -1 ) return strdup("404 Invalid target user");
512 iAmmount = atoi(ammount);
513 if( iAmmount <= 0 ) return strdup("407 Invalid Argument, ammount must be > zero\n");
516 switch( Transfer(Client->UID, uid, iAmmount, reason) )
519 return strdup("200 Give OK\n");
521 return strdup("402 Poor You\n");
526 * \brief Authenticate a user
527 * \return User ID, or -1 if authentication failed
529 int GetUserAuth(const char *Salt, const char *Username, const uint8_t *ProvidedHash)
533 int ofs = strlen(Username) + strlen(Salt);
534 char input[ ofs + 40 + 1];
535 char tmp[4 + strlen(Username) + 1]; // uid=%s
539 if( strcmp(Username, "tpg") == 0 )
540 return GetUserID("tpg");
543 if( strcmp(Username, "root") == 0 )
544 return GetUserID("root");
549 strcpy(input, Username);
551 // TODO: Get user's SHA-1 hash
552 sprintf(tmp, "uid=%s", Username);
553 ldap_search_s(ld, "", LDAP_SCOPE_BASE, tmp, "userPassword", 0, res);
555 sprintf(input+ofs, "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
556 h[ 0], h[ 1], h[ 2], h[ 3], h[ 4], h[ 5], h[ 6], h[ 7], h[ 8], h[ 9],
557 h[10], h[11], h[12], h[13], h[14], h[15], h[16], h[17], h[18], h[19]
559 // Then create the hash from the provided salt
560 // Compare that with the provided hash
566 // --- INTERNAL HELPERS ---
567 // TODO: Move to another file
568 void HexBin(uint8_t *Dest, char *Src, int BufSize)
571 for( i = 0; i < BufSize; i ++ )
575 if('0' <= *Src && *Src <= '9')
576 val |= (*Src-'0') << 4;
577 else if('A' <= *Src && *Src <= 'F')
578 val |= (*Src-'A'+10) << 4;
579 else if('a' <= *Src && *Src <= 'f')
580 val |= (*Src-'a'+10) << 4;
585 if('0' <= *Src && *Src <= '9')
587 else if('A' <= *Src && *Src <= 'F')
588 val |= (*Src-'A'+10);
589 else if('a' <= *Src && *Src <= 'f')
590 val |= (*Src-'a'+10);
597 for( ; i < BufSize; i++ )
602 * \brief Decode a Base64 value
604 int UnBase64(uint8_t *Dest, char *Src, int BufSize)
608 char *start_src = Src;
610 for( i = 0; i+2 < BufSize; i += 3 )
613 for( j = 0; j < 4; j++, Src ++ ) {
614 if('A' <= *Src && *Src <= 'Z')
615 val |= (*Src - 'A') << ((3-j)*6);
616 else if('a' <= *Src && *Src <= 'z')
617 val |= (*Src - 'a' + 26) << ((3-j)*6);
618 else if('0' <= *Src && *Src <= '9')
619 val |= (*Src - '0' + 52) << ((3-j)*6);
621 val |= 62 << ((3-j)*6);
623 val |= 63 << ((3-j)*6);
627 j --; // Ignore invalid characters
629 Dest[i ] = (val >> 16) & 0xFF;
630 Dest[i+1] = (val >> 8) & 0xFF;
631 Dest[i+2] = val & 0xFF;
637 Dest[i] = (val >> 16) & 0xFF;
639 Dest[i+1] = (val >> 8) & 0xFF;
641 return Src - start_src;