c - Using IPC Sys V -

i have server , client , want send file client server, using sys v ipc. problem sending of file, server creating file stops @ msgrcv_3 invalid argument (last while in server). maybe have idea.

snippet of server:

      while(1){     int ausgabe=0;   /* messageq */    if ((msqid = msgget(server_key, ipc_creat|ipc_excl|0666)) < 0){     perror("msgget_1");     exit(exit_failure);   }    /*  message empfangen */   if((msreturn = msgrcv(msqid, (void*)&name, sizeof(struct name),0,0))<0){     perror("msgrcv_1");     exit(exit_failure);   }        result.exists = fileexists(name.file_name);     printf("%d\n", result.exists);    /* message versenden*/   if((msreturn = msgsnd(msqid, (void*)&result, sizeof(struct result),0))<0){     perror("msgsnd_1");     exit(exit_failure);   }    if(result.exists == 42){     if((msreturn = msgrcv(msqid, (void*)&data, sizeof(struct data),0,0))<0){       perror("msgrcv_2");       exit(exit_failure);     }     creatfile = open(data.file_name, o_wronly | o_creat| o_excl , 0);       if(creatfile == -1){         perror("creratfile");         exit(exit_failure);       }     do{       if(msgrcv(msqid, (void*)&msg_body, sizeof(struct msg_body),0,0)<0){         perror("msgrcv_3");         exit(exit_failure);        }       buff_blub = write(creatfile, &msg_body.buffer, msg_body.bufsize);       if (buff_blub < 0){         perror("write");         exit(exit_failure);       }       ausgabe = ausgabe+msg_body.bufsize;     }     while(ausgabe != data.datasize);       chmod(data.file_name, 0644);   }   } 

snippet of client:

        strncpy(name.file_name, argv[2], sizeof(name.file_name) - 1);    /* message versenden*/     if((msreturn = msgsnd(msqid, (void*)&name, sizeof(struct name),0))<0){         perror("msgsnd");         exit(exit_failure);     }   /*  message empfangen */     if((msreturn = msgrcv(msqid, (void*)&result, sizeof(struct result),0,0))<0){         perror("msgrcv");         exit(exit_failure);     }        if(result.exists == 1){         puts("file exists");         exit(exit_failure);     }     else if(result.exists == 42){         file_read = open(argv[1], o_rdonly);         if (file_read > 0){             if (fstat(file_read, &sb)==-1){                 perror("fstat");                 return exit_failure;             }             strncpy(data.file_name, argv[2], sizeof(data.file_name) - 1);             data.datasize = sb.st_size;             data.c_pid = getpid();             if((msreturn = msgsnd(msqid, (void*)&data, sizeof(struct data),0))<0){                 perror("msgsnd");                 exit(exit_failure);             }             while((file_buffer = read (file_read, &msg_body.buffer, buf_size)) > 0){                 msg_body.bufsize = file_buffer;                 msg_body.prio = 2;                 if((msreturn = msgsnd(msqid, (void*)&msg_body, sizeof(struct msg_body),0))<0){                     perror("msgsnd");                     exit(exit_failure);                 }                }         close(file_read);         }      } return 1; } 

the structur:

#include <unistd.h> #if !defined(__msgbsp_h) #define __msgbsp_h #define buf_size 1024   struct data {   char file_name[255];   ssize_t datasize;   long c_pid; }; struct name {     char file_name[255]; }; struct result {   int exists; }; struct header {   int size; }; struct msg_body {     long prio;     ssize_t bufsize;     char buffer[buf_size]; }; #endif