sevprog.c

用Ｃ语言编的邮件系统（毕业论文）

#include<stdio.h>
#include<stdlib.h>
#include<errno.h>
#include<string.h>
#include<sys/types.h>
#include<netinet/in.h>
#include<sys/socket.h>
#include<sys/wait.h>

#include "mail.h"
#include "usrpass.h"

#define MAXSIZE 500
#define MYPORT 5500 
#define BACKLOG 10
define OK 1

typedef struct{
           int  mail_num;
           char to[MAXSIZE];
           char from[MAXSIZE];
           char subject[MAXSIZE];
           char content[MAXSIZE];
           time_t recvtime;
}MailStruct;

int ServerMain(int);

char GetSockChar(int); 
int SendSockChar(int,char);
int readline(int,void*,int);
int sockendline(int );
void CutEndl(char* str);

int RegisterSev(int );
int RecvUsrPswd(int,char* ,char* );
int  LoginSev(int );

int MailService(int,char*);
int SendMailList(int,char*);

int ReadMailSev(int sockfd);
int DelMailSev(int sockfd,char*Usr);
int SendMailSev(int sockfd,char*Usr);

int main()
{  
    int sockfd,new_fd;
    struct sockaddr_in their_addr;
    int sin_size;
 
    sockfd=StartListening();
   
    while(1)
    {
        sin_size=sizeof(struct sockaddr_in);
        new_fd=accept(sockfd,(struct sockaddr*)&their_addr,&sin_size);
        if (new_fd==-1) {
                   perror("accept"); 
                   continue;
         }
        printf("server:got connection from %s",inet_ntoa(their_addr.sin_addr));
        if (!fork())  {           
                                ServerMain(new_fd); 
                close(new_fd);
        }    
        close(new_fd);
     }
    while(waitpid(-1,NULL,WNOHANG)>0);
}


int             /* read a text line from a descriptor */
readline (int fd,void *vptr,int maxlen)
{
    int n,rc;
    char c,*ptr;
    
    ptr = vptr;
    for (n=1;n<maxlen;n++) {
      again:
        if ( (rc =read(fd,&c,1)) ==1) {
            *ptr++=c;
            if (c=='\n')
                break;         /* newline is stored,like fgets() */
        }else if (rc ==0) {
            if (n==1)
                return (0);   /* EOF,no data read */
            else
               break;
       }else{
            if (errno == EINTR)
                goto again;
            return(-1);     /* error,errno set by read() */
       }
    }
    *ptr=0;                /* null terminate like fgets() */
    return(n);
}
int sockendline(int sockfd)   /*ok*/
{
    const char ch='\n';
    if (write(sockfd,&ch,1)==1) 
        return 0;
    else -1;
}
void  CutEndl(char* str)
{
    int len;
    len=strlen(str);
    if (str[len-1]=='\n') 
                str[len-1]='\0';
}



int StartListening()     /*ok*/
{
   int sockfd;
   struct sockaddr_in my_addr;
   int sin_size;
 
   if ((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){
        perror("socket");
        exit(1);
    }
   
    my_addr.sin_family=AF_INET;
    my_addr.sin_port=htons(MYPORT);
    my_addr.sin_addr.s_addr=INADDR_ANY;
    bzero(&(my_addr.sin_zero),8);

    if (bind(sockfd,(struct sockaddr*) &my_addr,sizeof(struct sockaddr))==-1)
    {       
          perror("bindB");
          exit(1);
    }
 
    if  (listen(sockfd,BACKLOG)==-1) 
    {
             perror("listen");
             exit(1);
    }
    else printf("start listening the clients' connect request......\n");
    printf("\nserver state:waiting for a user's sevice request \n");
    return sockfd;
}


int ServerMain(int sockfd)     /*ok*/
{
    char Comch,Inforch;
    char recvbuf[MAXSIZE],sendbuf[MAXSIZE];
    char Username[MAXSIZE],Password[MAXSIZE];
    printf("\n\nserver state:waiting for client's command\n");
    Comch=GetSockChar(sockfd);
    printf("\nreceived command character:  %c\n",Comch);
    switch (Comch) {
              case 'R':RegisterSev(sockfd);
                                 break;
              case 'L': LoginSev(sockfd);
                                 break;
      }  
    return OK;
}
char GetSockChar(int sockfd)   
/*get a command char  or a signal char from socket*/
{
    char ch;
    do {
        read(sockfd,&ch,1);
     }while (!isalnum(ch));
    return ch;
} 
int  SendSockChar(int sockfd,char ch)     /*ok*/
/*send a signal char to client through socket*/
{
    return write(sockfd,&ch,1);
}

int RegisterSev(int sockfd)   /*ok*/
{      
      char Usr[MAXSIZE],Pswd[MAXSIZE];  
      char ch;
      RecvUsrPswd(sockfd,Usr,Pswd);       
      printf("received username:%s\n",Usr);
      printf("received password:%s\n",Pswd);
      UsrStore(Usr,Pswd);      /* to be written by TZJ*/
       SendSockChar(sockfd,'D');     
}

int  LoginSev(int sockfd)
{
        int ret;
        const char infch[2]={'F','T'};
        char Usr[MAXSIZE],Pswd[MAXSIZE];
        do {  
               RecvUsrPswd(sockfd,Usr,Pswd);         
                   
               printf("usrname=%s\n",Usr);
               printf("password=%s\n",Pswd); 
              
               ret=TestPasd(Usr,Pswd);      /* to be written by TZJ */
               printf("return is %d \n",ret);
          
               if (ret==1)  {         
                             SendSockChar(sockfd,infch[1]);
                             MailSevice(sockfd,Usr);
               }                 
               else SendSockChar(sockfd,infch[0]);
        }while (ret!=OK);
        return OK;
}
int RecvUsrPswd(int sockfd,char *Usr,char* Pswd)   /*ok*/
{
      char ch;
      ch=GetSockChar(sockfd);
      if (ch='B') {
          readline(sockfd,Usr,MAXSIZE);
          CutEndl(Usr);
          readline(sockfd,Pswd,MAXSIZE);
          CutEndl(Pswd);
      }
}

int MailSevice(int sockfd,char*Usr)
{
   char ch; 
   printf("start mail sevice\n");
         
   SendMailList(sockfd,Usr);
   
   for (; ;) {
             printf("\nserver:waiting for client's command\n");
             ch=GetSockChar(sockfd);
             printf("received command char:%c",ch);
             switch(ch){
                    case 'R':ReadMailSev(sockfd);
                               break;
                    case 'D':DelMailSev(sockfd,Usr);
                               break;
                    case 'S': SendMailSev(sockfd,Usr);
                              break;
                    case 'E': printf("sevice for one client completed\n");
                                      return OK;
                   default:  break;
              }
   }
   return OK;
}  

int SendMailList(int sockfd,char*Usr)
{
    FILE *stream;
    char c,buf[MAXSIZE],*ptr;

    getmsgfrmdb(Usr);
    printf("after getmsgfrmdb() \n");   
 
    stream = fopen(TMPMSGFILE,"r");
    ptr=buf;
    while ((c=fgetc(stream))!=EOF)
           *ptr++=c;
    *ptr='\0';
    fclose(stream);
    putchar('\n');
    puts(buf);
    printf("start sending mail list for %s......",Usr);
    write(sockfd,buf,strlen(buf));
    printf("%d bytes been sent\n",strlen(buf));
    SendSockChar(sockfd,'\0');   
    printf("sending maillist [OK!]");
    return OK;
}

int ReadMailSev(int sockfd)
{
    char ch, buf[MAXSIZE],MailNum[4],*ptr;
    MailStruct  *TempMail;
    int mail_id,i; 
    TempMail=(MailStruct*)malloc(sizeof(MailStruct));
    ch=GetSockChar(sockfd);
    readline(sockfd,MailNum,MAXSIZE);
    CutEndl(MailNum);
    mail_id=atoi(MailNum);
    printf("Received Mail id: %d\n ",mail_id);
    GetMail(mail_id,buf);   /*to be written by TZJ*/
         
    SendSockChar(sockfd,'B');
    write(sockfd,buf,strlen(buf));
      
    SendSockChar(sockfd,'\0');
    ch=GetSockChar(sockfd);
    if (ch=='D') 
          return OK;
    else return -1;
}

int DelMailSev(int sockfd,char*Usr)
{
    char ch,MailNum[4];
    int mail_id;
    ch=GetSockChar(sockfd);
    readline(sockfd,MailNum,MAXSIZE);
    CutEndl(MailNum);
    mail_id=atoi(MailNum);
    DelMail(mail_id,Usr);   /*to be written by TZJ*/
    SendSockChar(sockfd,'D');
    ch=GetSockChar(sockfd);
    if (ch=='D')
       return OK;
    else return -1;
}
    
int SendMailSev(int sockfd,char* Usr)
{
    MailStruct *TempMail;
    struct message *MailToStore;

    char ch,buf[MAXSIZE];
    int i;
    printf("\nSendMailSev\n");
    TempMail=(MailStruct*)malloc(sizeof(MailStruct));
    strcpy(TempMail->from,Usr);
    strcpy(TempMail->content,Usr);
    strcat(TempMail->content,"\n");

    ch=GetSockChar(sockfd);

    readline(sockfd,buf,MAXSIZE);
    CutEndl(buf);
    strcpy(TempMail->to,buf); 
    strcat(TempMail->content,buf);
    strcat(TempMail->content,"\n");
    
    readline(sockfd,buf,MAXSIZE);
    CutEndl(buf);
    strcpy(TempMail->subject,buf);
    strcat(TempMail->content,buf);
    strcat(TempMail->content,"\n");

    read(sockfd,&ch,1);
    i=0;
    while(ch!=0) {
         buf[i++]=ch;
         read(sockfd,&ch,1);
     }
    buf[i]='\0'; 
    strcat(TempMail->content,buf);
    strcat(TempMail->content,"\n");
   
    TempMail->recvtime=time((time_t*)NULL);
  
    MailToStore=(struct message*)malloc(sizeof(struct message));
    MailToStore->to=TempMail->to;
    MailToStore->from=TempMail->from;
    MailToStore->recvtime=TempMail->recvtime;
    MailToStore->sendtime=TempMail->recvtime;
    MailToStore->subject=TempMail->subject;
    MailToStore->content=TempMail->content;
    sprintf(buf,"%d",(int)MailToStore->recvtime);
    MailToStore->messageid=buf;
     
    printf("MailToStore-> content=\n%s\n",MailToStore->content);
                     
    StoreMail(MailToStore);         /* to be written by TZJ */
    SendSockChar(sockfd,'D');
    ch=GetSockChar(sockfd);
    if (ch=='D')  
          return OK;
    else return -1;
}