It's been so long, I don't know what I did
[tpg/opendispense2.git] / server / src / server.c
index 8c87c65..7f0debb 100644 (file)
 #include <stdlib.h>
 #include "common.h"
 #include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
 #include <string.h>
 
 #define MAX_CONNECTION_QUEUE   5
-#define INPUT_BUFFER_SIZE      128
+#define INPUT_BUFFER_SIZE      256
+
+#define HASH_TYPE      SHA512
+#define HASH_LENGTH    64
 
 #define MSG_STR_TOO_LONG       "499 Command too long (limit "EXPSTR(INPUT_BUFFER_SIZE)")\n"
 
 // === TYPES ===
 typedef struct sClient
 {
+        int    ID;     // Client ID
+        
+        int    bIsTrusted;     // Is the connection from a trusted host/port
+       
+       char    *Username;
+       char    Salt[9];
+       
         int    UID;
         int    bIsAuthed;
 }      tClient;
 
 // === PROTOTYPES ===
 void   Server_Start(void);
-void   Server_HandleClient(int Socket);
+void   Server_HandleClient(int Socket, int bTrusted);
 char   *Server_ParseClientCommand(tClient *Client, char *CommandString);
+// --- Commands ---
 char   *Server_Cmd_USER(tClient *Client, char *Args);
+char   *Server_Cmd_PASS(tClient *Client, char *Args);
+char   *Server_Cmd_AUTOAUTH(tClient *Client, char *Args);
+// --- Helpers ---
+void   HexBin(uint8_t *Dest, char *Src, int BufSize);
 
 // === GLOBALS ===
  int   giServer_Port = 1020;
@@ -39,7 +57,9 @@ struct sClientCommand {
        char    *Name;
        char    *(*Function)(tClient *Client, char *Arguments);
 }      gaServer_Commands[] = {
-       {"USER", Server_Cmd_USER}
+       {"USER", Server_Cmd_USER},
+       {"PASS", Server_Cmd_PASS},
+       {"AUTOAUTH", Server_Cmd_AUTOAUTH}
 };
 #define NUM_COMMANDS   (sizeof(gaServer_Commands)/sizeof(gaServer_Commands[0]))
 
@@ -49,21 +69,103 @@ struct sClientCommand {
  */
 void Server_Start(void)
 {
+        int    server_socket, client_socket;
+       struct sockaddr_in      server_addr, client_addr;
+
        // Create Server
+       server_socket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+       if( server_socket < 0 ) {
+               fprintf(stderr, "ERROR: Unable to create server socket\n");
+               return ;
+       }
+       
+       // Make listen address
+       memset(&server_addr, 0, sizeof(server_addr));
+       server_addr.sin_family = AF_INET;       // Internet Socket
+       server_addr.sin_addr.s_addr = htonl(INADDR_ANY);        // Listen on all interfaces
+       server_addr.sin_port = htons(giServer_Port);    // Port
+
+       // Bind
+       if( bind(server_socket, (struct sockaddr *) &server_addr, sizeof(server_addr)) < 0 ) {
+               fprintf(stderr, "ERROR: Unable to bind to 0.0.0.0:%i\n", giServer_Port);
+               return ;
+       }
+       
+       // Listen
+       if( listen(server_socket, MAX_CONNECTION_QUEUE) < 0 ) {
+               fprintf(stderr, "ERROR: Unable to listen to socket\n");
+               return ;
+       }
+       
+       printf("Listening on 0.0.0.0:%i\n", giServer_Port);
+       
+       for(;;)
+       {
+               uint    len = sizeof(client_addr);
+                int    bTrusted = 0;
+               
+               client_socket = accept(server_socket, (struct sockaddr *) &client_addr, &len);
+               if(client_socket < 0) {
+                       fprintf(stderr, "ERROR: Unable to accept client connection\n");
+                       return ;
+               }
+               
+               if(giDebugLevel >= 2) {
+                       char    ipstr[INET_ADDRSTRLEN];
+                       inet_ntop(AF_INET, &client_addr.sin_addr, ipstr, INET_ADDRSTRLEN);
+                       printf("Client connection from %s:%i\n",
+                               ipstr, ntohs(client_addr.sin_port));
+               }
+               
+               // Trusted Connections
+               if( ntohs(client_addr.sin_port) < 1024 )
+               {
+                       // TODO: Make this runtime configurable
+                       switch( ntohl( client_addr.sin_addr.s_addr ) )
+                       {
+                       case 0x7F000001:        // 127.0.0.1    localhost
+                       //case 0x825E0D00:      // 130.95.13.0
+                       case 0x825E0D12:        // 130.95.13.18 mussel
+                       case 0x825E0D17:        // 130.95.13.23 martello
+                               bTrusted = 1;
+                               break;
+                       default:
+                               break;
+                       }
+               }
+               
+               // TODO: Multithread this?
+               Server_HandleClient(client_socket, bTrusted);
+               
+               close(client_socket);
+       }
 }
 
 /**
  * \brief Reads from a client socket and parses the command strings
+ * \param Socket       Client socket number/handle
+ * \param bTrusted     Is the client trusted?
  */
-void Server_HandleClient(int Socket)
+void Server_HandleClient(int Socket, int bTrusted)
 {
        char    inbuf[INPUT_BUFFER_SIZE];
        char    *buf = inbuf;
         int    remspace = INPUT_BUFFER_SIZE-1;
         int    bytes = -1;
        tClient clientInfo = {0};
-               
+       
+       // Initialise Client info
+       clientInfo.ID = giServer_NextClientID ++;
+       clientInfo.bIsTrusted = bTrusted;
+       
        // Read from client
+       /*
+        * Notes:
+        * - The `buf` and `remspace` variables allow a line to span several
+        *   calls to recv(), if a line is not completed in one recv() call
+        *   it is saved to the beginning of `inbuf` and `buf` is updated to
+        *   the end of it.
+        */
        while( (bytes = recv(Socket, buf, remspace, 0)) > 0 )
        {
                char    *eol, *start;
@@ -105,11 +207,17 @@ void Server_HandleClient(int Socket)
                fprintf(stderr, "ERROR: Unable to recieve from client on socket %i\n", Socket);
                return ;
        }
+       
+       if(giDebugLevel >= 2) {
+               printf("Client %i: Disconnected\n", clientInfo.ID);
+       }
 }
 
 /**
  * \brief Parses a client command and calls the required helper function
  * \param Client       Pointer to client state structure
+ * \param CommandString        Command from client (single line of the command)
+ * \return Heap String to return to the client
  */
 char *Server_ParseClientCommand(tClient *Client, char *CommandString)
 {
@@ -141,23 +249,25 @@ char *Server_ParseClientCommand(tClient *Client, char *CommandString)
 // ---
 /**
  * \brief Set client username
+ * 
+ * Usage: USER <username>
  */
 char *Server_Cmd_USER(tClient *Client, char *Args)
 {
        char    *ret;
        
        // Debug!
-       if( gbDebugLevel )
-               printf("Client %i authenticating as '%s'\n", Args);
+       if( giDebugLevel )
+               printf("Client %i authenticating as '%s'\n", Client->ID, Args);
        
        // Save username
        if(Client->Username)
                free(Client->Username);
        Client->Username = strdup(Args);
        
+       #if USE_SALT
        // Create a salt (that changes if the username is changed)
-       if(!Client->Salt)
-               Client->Salt = malloc(9);
+       // Yes, I know, I'm a little paranoid, but who isn't?
        Client->Salt[0] = 0x21 + (rand()&0x3F);
        Client->Salt[1] = 0x21 + (rand()&0x3F);
        Client->Salt[2] = 0x21 + (rand()&0x3F);
@@ -170,6 +280,140 @@ char *Server_Cmd_USER(tClient *Client, char *Args)
        // "100 Salt xxxxXXXX\n"
        ret = strdup("100 SALT xxxxXXXX\n");
        sprintf(ret, "100 SALT %s\n", Client->Salt);
-       
+       #else
+       ret = strdup("100 User Set\n");
+       #endif
        return ret;
 }
+
+/**
+ * \brief Authenticate as a user
+ * 
+ * Usage: PASS <hash>
+ */
+char *Server_Cmd_PASS(tClient *Client, char *Args)
+{
+       uint8_t clienthash[HASH_LENGTH] = {0};
+       
+       // Read user's hash
+       HexBin(clienthash, Args, HASH_LENGTH);
+       
+       if( giDebugLevel ) {
+                int    i;
+               printf("Client %i: Password hash ", Client->ID);
+               for(i=0;i<HASH_LENGTH;i++)
+                       printf("%02x", clienthash[i]&0xFF);
+               printf("\n");
+       }
+       
+       return strdup("401 Auth Failure\n");
+}
+
+/**
+ * \brief Authenticate as a user without a password
+ * 
+ * Usage: AUTOAUTH <user>
+ */
+char *Server_Cmd_AUTOAUTH(tClient *Client, char *Args)
+{
+       char    *spos = strchr(Args, ' ');
+       if(spos)        *spos = '\0';   // Remove characters after the ' '
+       
+       // Check if trusted
+       if( !Client->bIsTrusted ) {
+               if(giDebugLevel)
+                       printf("Client %i: Untrusted client attempting to AUTOAUTH\n", Client->ID);
+               return strdup("401 Untrusted\n");
+       }
+       
+       // Get UID
+       Client->UID = GetUserID( Args );
+       if( Client->UID < 0 ) {
+               if(giDebugLevel)
+                       printf("Client %i: Unknown user '%s'\n", Client->ID, Args);
+               return strdup("401 Auth Failure\n");
+       }
+       
+       if(giDebugLevel)
+               printf("Client %i: Authenticated as '%s' (%i)\n", Client->ID, Args, Client->UID);
+       
+       return strdup("200 Auth OK\n");
+}
+
+// --- INTERNAL HELPERS ---
+// TODO: Move to another file
+void HexBin(uint8_t *Dest, char *Src, int BufSize)
+{
+        int    i;
+       for( i = 0; i < BufSize; i ++ )
+       {
+               uint8_t val = 0;
+               
+               if('0' <= *Src && *Src <= '9')
+                       val |= (*Src-'0') << 4;
+               else if('A' <= *Src && *Src <= 'F')
+                       val |= (*Src-'A'+10) << 4;
+               else if('a' <= *Src && *Src <= 'f')
+                       val |= (*Src-'a'+10) << 4;
+               else
+                       break;
+               Src ++;
+               
+               if('0' <= *Src && *Src <= '9')
+                       val |= (*Src-'0');
+               else if('A' <= *Src && *Src <= 'F')
+                       val |= (*Src-'A'+10);
+               else if('a' <= *Src && *Src <= 'f')
+                       val |= (*Src-'a'+10);
+               else
+                       break;
+               Src ++;
+               
+               Dest[i] = val;
+       }
+       for( ; i < BufSize; i++ )
+               Dest[i] = 0;
+}
+
+/**
+ * \brief Decode a Base64 value
+ */
+int UnBase64(uint8_t *Dest, char *Src, int BufSize)
+{
+       uint32_t        val;
+        int    i, j;
+       char    *start_src = Src;
+       
+       for( i = 0; i+2 < BufSize; i += 3 )
+       {
+               val = 0;
+               for( j = 0; j < 4; j++, Src ++ ) {
+                       if('A' <= *Src && *Src <= 'Z')
+                               val |= (*Src - 'A') << ((3-j)*6);
+                       else if('a' <= *Src && *Src <= 'z')
+                               val |= (*Src - 'a' + 26) << ((3-j)*6);
+                       else if('0' <= *Src && *Src <= '9')
+                               val |= (*Src - '0' + 52) << ((3-j)*6);
+                       else if(*Src == '+')
+                               val |= 62 << ((3-j)*6);
+                       else if(*Src == '/')
+                               val |= 63 << ((3-j)*6);
+                       else if(!*Src)
+                               break;
+                       else if(*Src != '=')
+                               j --;   // Ignore invalid characters
+               }
+               Dest[i  ] = (val >> 16) & 0xFF;
+               Dest[i+1] = (val >> 8) & 0xFF;
+               Dest[i+2] = val & 0xFF;
+               if(j != 4)      break;
+       }
+       
+       // Finish things off
+       if(i   < BufSize)
+               Dest[i] = (val >> 16) & 0xFF;
+       if(i+1 < BufSize)
+               Dest[i+1] = (val >> 8) & 0xFF;
+       
+       return Src - start_src;
+}

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