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);
58 char *Server_Cmd_GIVE(tClient *Client, char *Args);
59 char *Server_Cmd_ADD(tClient *Client, char *Args);
60 char *Server_Cmd_USERINFO(tClient *Client, char *Args);
62 int GetUserAuth(const char *Salt, const char *Username, const uint8_t *Hash);
63 void HexBin(uint8_t *Dest, char *Src, int BufSize);
66 int giServer_Port = 1020;
67 int giServer_NextClientID = 1;
69 struct sClientCommand {
71 char *(*Function)(tClient *Client, char *Arguments);
72 } gaServer_Commands[] = {
73 {"USER", Server_Cmd_USER},
74 {"PASS", Server_Cmd_PASS},
75 {"AUTOAUTH", Server_Cmd_AUTOAUTH},
76 {"ENUM_ITEMS", Server_Cmd_ENUMITEMS},
77 {"ITEM_INFO", Server_Cmd_ITEMINFO},
78 {"DISPENSE", Server_Cmd_DISPENSE},
79 {"GIVE", Server_Cmd_GIVE},
80 {"ADD", Server_Cmd_ADD},
81 {"USER_INFO", Server_Cmd_USERINFO}
83 #define NUM_COMMANDS (sizeof(gaServer_Commands)/sizeof(gaServer_Commands[0]))
88 * \brief Open listenting socket and serve connections
90 void Server_Start(void)
93 struct sockaddr_in server_addr, client_addr;
95 atexit(Server_Cleanup);
98 giServer_Socket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
99 if( giServer_Socket < 0 ) {
100 fprintf(stderr, "ERROR: Unable to create server socket\n");
104 // Make listen address
105 memset(&server_addr, 0, sizeof(server_addr));
106 server_addr.sin_family = AF_INET; // Internet Socket
107 server_addr.sin_addr.s_addr = htonl(INADDR_ANY); // Listen on all interfaces
108 server_addr.sin_port = htons(giServer_Port); // Port
111 if( bind(giServer_Socket, (struct sockaddr *) &server_addr, sizeof(server_addr)) < 0 ) {
112 fprintf(stderr, "ERROR: Unable to bind to 0.0.0.0:%i\n", giServer_Port);
118 if( listen(giServer_Socket, MAX_CONNECTION_QUEUE) < 0 ) {
119 fprintf(stderr, "ERROR: Unable to listen to socket\n");
124 printf("Listening on 0.0.0.0:%i\n", giServer_Port);
128 uint len = sizeof(client_addr);
131 client_socket = accept(giServer_Socket, (struct sockaddr *) &client_addr, &len);
132 if(client_socket < 0) {
133 fprintf(stderr, "ERROR: Unable to accept client connection\n");
137 if(giDebugLevel >= 2) {
138 char ipstr[INET_ADDRSTRLEN];
139 inet_ntop(AF_INET, &client_addr.sin_addr, ipstr, INET_ADDRSTRLEN);
140 printf("Client connection from %s:%i\n",
141 ipstr, ntohs(client_addr.sin_port));
144 // Trusted Connections
145 if( ntohs(client_addr.sin_port) < 1024 )
147 // TODO: Make this runtime configurable
148 switch( ntohl( client_addr.sin_addr.s_addr ) )
150 case 0x7F000001: // 127.0.0.1 localhost
151 //case 0x825E0D00: // 130.95.13.0
152 case 0x825E0D12: // 130.95.13.18 mussel
153 case 0x825E0D17: // 130.95.13.23 martello
161 // TODO: Multithread this?
162 Server_HandleClient(client_socket, bTrusted);
164 close(client_socket);
168 void Server_Cleanup(void)
170 printf("Close(%i)\n", giServer_Socket);
171 close(giServer_Socket);
175 * \brief Reads from a client socket and parses the command strings
176 * \param Socket Client socket number/handle
177 * \param bTrusted Is the client trusted?
179 void Server_HandleClient(int Socket, int bTrusted)
181 char inbuf[INPUT_BUFFER_SIZE];
183 int remspace = INPUT_BUFFER_SIZE-1;
185 tClient clientInfo = {0};
187 // Initialise Client info
188 clientInfo.ID = giServer_NextClientID ++;
189 clientInfo.bIsTrusted = bTrusted;
194 * - The `buf` and `remspace` variables allow a line to span several
195 * calls to recv(), if a line is not completed in one recv() call
196 * it is saved to the beginning of `inbuf` and `buf` is updated to
199 while( (bytes = recv(Socket, buf, remspace, 0)) > 0 )
202 buf[bytes] = '\0'; // Allow us to use stdlib string functions on it
206 while( (eol = strchr(start, '\n')) )
210 ret = Server_ParseClientCommand(&clientInfo, start);
211 printf("ret = %s", ret);
212 // `ret` is a string on the heap
213 send(Socket, ret, strlen(ret), 0);
218 // Check if there was an incomplete line
219 if( *start != '\0' ) {
220 int tailBytes = bytes - (start-buf);
221 // Roll back in buffer
222 memcpy(inbuf, start, tailBytes);
223 remspace -= tailBytes;
225 send(Socket, MSG_STR_TOO_LONG, sizeof(MSG_STR_TOO_LONG), 0);
227 remspace = INPUT_BUFFER_SIZE - 1;
232 remspace = INPUT_BUFFER_SIZE - 1;
238 fprintf(stderr, "ERROR: Unable to recieve from client on socket %i\n", Socket);
242 if(giDebugLevel >= 2) {
243 printf("Client %i: Disconnected\n", clientInfo.ID);
248 * \brief Parses a client command and calls the required helper function
249 * \param Client Pointer to client state structure
250 * \param CommandString Command from client (single line of the command)
251 * \return Heap String to return to the client
253 char *Server_ParseClientCommand(tClient *Client, char *CommandString)
258 // Split at first space
259 space = strchr(CommandString, ' ');
269 for( i = 0; i < NUM_COMMANDS; i++ )
271 if(strcmp(CommandString, gaServer_Commands[i].Name) == 0)
272 return gaServer_Commands[i].Function(Client, args);
275 return strdup("400 Unknown Command\n");
282 * \brief Set client username
284 * Usage: USER <username>
286 char *Server_Cmd_USER(tClient *Client, char *Args)
292 printf("Client %i authenticating as '%s'\n", Client->ID, Args);
296 free(Client->Username);
297 Client->Username = strdup(Args);
300 // Create a salt (that changes if the username is changed)
301 // Yes, I know, I'm a little paranoid, but who isn't?
302 Client->Salt[0] = 0x21 + (rand()&0x3F);
303 Client->Salt[1] = 0x21 + (rand()&0x3F);
304 Client->Salt[2] = 0x21 + (rand()&0x3F);
305 Client->Salt[3] = 0x21 + (rand()&0x3F);
306 Client->Salt[4] = 0x21 + (rand()&0x3F);
307 Client->Salt[5] = 0x21 + (rand()&0x3F);
308 Client->Salt[6] = 0x21 + (rand()&0x3F);
309 Client->Salt[7] = 0x21 + (rand()&0x3F);
311 // TODO: Also send hash type to use, (SHA1 or crypt according to [DAA])
312 ret = mkstr("100 SALT %s\n", Client->Salt);
314 ret = strdup("100 User Set\n");
320 * \brief Authenticate as a user
324 char *Server_Cmd_PASS(tClient *Client, char *Args)
326 uint8_t clienthash[HASH_LENGTH] = {0};
329 HexBin(clienthash, Args, HASH_LENGTH);
331 // TODO: Decrypt password passed
333 Client->UID = GetUserAuth(Client->Salt, Client->Username, clienthash);
335 if( Client->UID != -1 ) {
336 Client->bIsAuthed = 1;
337 return strdup("200 Auth OK\n");
342 printf("Client %i: Password hash ", Client->ID);
343 for(i=0;i<HASH_LENGTH;i++)
344 printf("%02x", clienthash[i]&0xFF);
348 return strdup("401 Auth Failure\n");
352 * \brief Authenticate as a user without a password
354 * Usage: AUTOAUTH <user>
356 char *Server_Cmd_AUTOAUTH(tClient *Client, char *Args)
358 char *spos = strchr(Args, ' ');
359 if(spos) *spos = '\0'; // Remove characters after the ' '
362 if( !Client->bIsTrusted ) {
364 printf("Client %i: Untrusted client attempting to AUTOAUTH\n", Client->ID);
365 return strdup("401 Untrusted\n");
369 Client->UID = GetUserID( Args );
370 if( Client->UID < 0 ) {
372 printf("Client %i: Unknown user '%s'\n", Client->ID, Args);
373 return strdup("401 Auth Failure\n");
377 printf("Client %i: Authenticated as '%s' (%i)\n", Client->ID, Args, Client->UID);
379 return strdup("200 Auth OK\n");
383 * \brief Enumerate the items that the server knows about
385 char *Server_Cmd_ENUMITEMS(tClient *Client, char *Args)
391 retLen = snprintf(NULL, 0, "201 Items %i", giNumItems);
393 for( i = 0; i < giNumItems; i ++ )
395 retLen += snprintf(NULL, 0, " %s:%i", gaItems[i].Handler->Name, gaItems[i].ID);
398 ret = malloc(retLen+1);
400 retLen += sprintf(ret+retLen, "201 Items %i", giNumItems);
402 for( i = 0; i < giNumItems; i ++ ) {
403 retLen += sprintf(ret+retLen, " %s:%i", gaItems[i].Handler->Name, gaItems[i].ID);
411 tItem *_GetItemFromString(char *String)
415 char *colon = strchr(String, ':');
427 for( i = 0; i < giNumHandlers; i ++ )
429 if( strcmp(gaHandlers[i]->Name, type) == 0) {
430 handler = gaHandlers[i];
439 for( i = 0; i < giNumItems; i ++ )
441 if( gaItems[i].Handler != handler ) continue;
442 if( gaItems[i].ID != num ) continue;
449 * \brief Fetch information on a specific item
451 char *Server_Cmd_ITEMINFO(tClient *Client, char *Args)
455 tItem *item = _GetItemFromString(Args);
458 return strdup("406 Bad Item ID\n");
462 retLen = snprintf(NULL, 0, "202 Item %s:%i %i %s\n",
463 item->Handler->Name, item->ID, item->Price, item->Name);
464 ret = malloc(retLen+1);
465 sprintf(ret, "202 Item %s:%i %i %s\n",
466 item->Handler->Name, item->ID, item->Price, item->Name);
471 char *Server_Cmd_DISPENSE(tClient *Client, char *Args)
475 if( !Client->bIsAuthed ) return strdup("401 Not Authenticated\n");
477 item = _GetItemFromString(Args);
479 return strdup("406 Bad Item ID\n");
482 switch( ret = DispenseItem( Client->UID, item ) )
484 case 0: return strdup("200 Dispense OK\n");
485 case 1: return strdup("501 Unable to dispense\n");
486 case 2: return strdup("402 Poor You\n");
488 return strdup("500 Dispense Error\n");
492 char *Server_Cmd_GIVE(tClient *Client, char *Args)
494 char *recipient, *ammount, *reason;
497 if( !Client->bIsAuthed ) return strdup("401 Not Authenticated\n");
501 ammount = strchr(Args, ' ');
502 if( !ammount ) return strdup("407 Invalid Argument, expected 3 parameters, 1 encountered\n");
506 reason = strchr(ammount, ' ');
507 if( !reason ) return strdup("407 Invalid Argument, expected 3 parameters, 2 encountered\n");
512 uid = GetUserID(recipient);
513 if( uid == -1 ) return strdup("404 Invalid target user");
516 iAmmount = atoi(ammount);
517 if( iAmmount <= 0 ) return strdup("407 Invalid Argument, ammount must be > zero\n");
520 switch( DispenseGive(Client->UID, uid, iAmmount, reason) )
523 return strdup("200 Give OK\n");
525 return strdup("402 Poor You\n");
527 return strdup("500 Unknown error\n");
531 char *Server_Cmd_ADD(tClient *Client, char *Args)
533 char *user, *ammount, *reason;
536 if( !Client->bIsAuthed ) return strdup("401 Not Authenticated\n");
540 ammount = strchr(Args, ' ');
541 if( !ammount ) return strdup("407 Invalid Argument, expected 3 parameters, 1 encountered\n");
545 reason = strchr(ammount, ' ');
546 if( !reason ) return strdup("407 Invalid Argument, expected 3 parameters, 2 encountered\n");
550 // TODO: Check if the current user is in coke/higher
553 uid = GetUserID(user);
554 if( uid == -1 ) return strdup("404 Invalid user");
557 iAmmount = atoi(ammount);
558 if( iAmmount == 0 && ammount[0] != '0' ) return strdup("407 Invalid Argument, ammount must be > zero\n");
561 switch( DispenseAdd(uid, Client->UID, iAmmount, reason) )
564 return strdup("200 Add OK\n");
566 return strdup("402 Poor Guy\n");
568 return strdup("500 Unknown error\n");
572 char *Server_Cmd_USERINFO(tClient *Client, char *Args)
578 space = strchr(user, ' ');
579 if(space) *space = '\0';
582 uid = GetUserID(user);
583 if( uid == -1 ) return strdup("404 Invalid user");
585 return mkstr("202 User %s %i user\n", user, GetBalance(uid));
589 * \brief Authenticate a user
590 * \return User ID, or -1 if authentication failed
592 int GetUserAuth(const char *Salt, const char *Username, const uint8_t *ProvidedHash)
596 int ofs = strlen(Username) + strlen(Salt);
597 char input[ ofs + 40 + 1];
598 char tmp[4 + strlen(Username) + 1]; // uid=%s
602 if( strcmp(Username, "tpg") == 0 )
603 return GetUserID("tpg");
606 if( strcmp(Username, "root") == 0 )
607 return GetUserID("root");
612 strcpy(input, Username);
614 // TODO: Get user's SHA-1 hash
615 sprintf(tmp, "uid=%s", Username);
616 ldap_search_s(ld, "", LDAP_SCOPE_BASE, tmp, "userPassword", 0, res);
618 sprintf(input+ofs, "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
619 h[ 0], h[ 1], h[ 2], h[ 3], h[ 4], h[ 5], h[ 6], h[ 7], h[ 8], h[ 9],
620 h[10], h[11], h[12], h[13], h[14], h[15], h[16], h[17], h[18], h[19]
622 // Then create the hash from the provided salt
623 // Compare that with the provided hash
629 // --- INTERNAL HELPERS ---
630 // TODO: Move to another file
631 void HexBin(uint8_t *Dest, char *Src, int BufSize)
634 for( i = 0; i < BufSize; i ++ )
638 if('0' <= *Src && *Src <= '9')
639 val |= (*Src-'0') << 4;
640 else if('A' <= *Src && *Src <= 'F')
641 val |= (*Src-'A'+10) << 4;
642 else if('a' <= *Src && *Src <= 'f')
643 val |= (*Src-'a'+10) << 4;
648 if('0' <= *Src && *Src <= '9')
650 else if('A' <= *Src && *Src <= 'F')
651 val |= (*Src-'A'+10);
652 else if('a' <= *Src && *Src <= 'f')
653 val |= (*Src-'a'+10);
660 for( ; i < BufSize; i++ )
665 * \brief Decode a Base64 value
667 int UnBase64(uint8_t *Dest, char *Src, int BufSize)
671 char *start_src = Src;
673 for( i = 0; i+2 < BufSize; i += 3 )
676 for( j = 0; j < 4; j++, Src ++ ) {
677 if('A' <= *Src && *Src <= 'Z')
678 val |= (*Src - 'A') << ((3-j)*6);
679 else if('a' <= *Src && *Src <= 'z')
680 val |= (*Src - 'a' + 26) << ((3-j)*6);
681 else if('0' <= *Src && *Src <= '9')
682 val |= (*Src - '0' + 52) << ((3-j)*6);
684 val |= 62 << ((3-j)*6);
686 val |= 63 << ((3-j)*6);
690 j --; // Ignore invalid characters
692 Dest[i ] = (val >> 16) & 0xFF;
693 Dest[i+1] = (val >> 8) & 0xFF;
694 Dest[i+2] = val & 0xFF;
700 Dest[i] = (val >> 16) & 0xFF;
702 Dest[i+1] = (val >> 8) & 0xFF;
704 return Src - start_src;