c sendfile doesn't works the 2nd time

This is the part of the ftp cmd "LIST" :

Code:

---

    if(recv(newsockd, buffer, 5, 0) < 0){
            perror("Errore nella ricezione comando LIST");
            onexit(newsockd, sockd, 0, 2);
    }
    other = strtok(buffer, "\n");
    if(strcmp(other, "LIST") == 0){
            printf("Ricevuta richiesta LIST\n");
    } else onexit(newsockd, sockd, 0, 2);


    count = file_list("./", &files);
    if((fp_list = fopen("listfiles.txt", "w")) == NULL){
      perror("Impossibile aprire il file per la scrittura LIST");
      onexit(newsockd, sockd, 0, 2);
    }
    for(i=0; i < count; i++){
      if(strcmp(files[i], "DIR ..") == 0 || strcmp(files[i], "DIR .") == 0) continue;
      else{
        fprintf(fp_list, "%s\n", files[i]);
      }
    }
    fclose(fp_list);
    if((fpl = open("listfiles.txt", O_RDONLY)) < 0){
      perror("open file with open");
      onexit(newsockd, sockd, 0, 2);
      exit(1);
    }
    if(fstat(fpl, &fileStat) < 0){
      perror("Errore fstat");
      onexit(newsockd, sockd, fpl, 3);
    }
    fsize = fileStat.st_size;
    if(send(newsockd, &fsize, sizeof(fsize), 0) < 0){
      perror("Errore durante l'invio grande file list");
      onexit(newsockd, sockd, fpl, 3);
    }
    rc_list = sendfile(newsockd, fpl, &offset_list, fileStat.st_size);
    if(rc_list == -1){
      perror("Invio file list non riuscito");
      onexit(newsockd, sockd, fpl, 3);
    }
    if((uint32_t)rc_list != fsize){
      fprintf(stderr, "Trasferimento incompleto: %d di %d bytes inviati\n", rc_list, (int)fileStat.st_size);
      onexit(newsockd, sockd, fpl, 3);
    }
    close(fpl);
    if(remove( "listfiles.txt" ) == -1 ){
      perror("errore cancellazione file");
      onexit(newsockd, sockd, 0, 2);
    }
                memset(buffer, 0, sizeof(buffer));

---

this is the function file_list:

Code:

---

#include "prototypes.h"


uint32_t file_list(char *path, char ***ls){
        DIR *dp;
  struct stat fileStat;
  struct dirent *ep = NULL;
  uint32_t len, count = 0;
  int file = 0;
  *ls = NULL;
  dp = opendir (path);
  if(dp == NULL){
    fprintf(stderr, "Non esiste la directory: %s\n", path);
    exit(1);
  }


  ep = readdir(dp);
  while(NULL != ep){
    count++;
    ep = readdir(dp);
  }
  rewinddir(dp);


  *ls = calloc(count, sizeof(char *));
  count = 0;
  ep = readdir(dp);
  while(ep != NULL){
    if((file = open(ep->d_name, O_RDONLY)) < 0){
      perror("apertura file");
      exit(1);
    }
    if(fstat(file, &fileStat) != 0){
      perror("filestat");
      free(*ls);
      close(file);
      exit(EXIT_FAILURE);
    }
    close(file);
    if(S_ISDIR(fileStat.st_mode)){
      len = strlen(ep->d_name);
      (*ls)[count] = malloc(len+5); /* lunghezza stringa + "DIR \n" */
      strcpy((*ls)[count], "DIR "); /* copio DIR */
      strcat((*ls)[count++], ep->d_name); /* concateno la stringa DIR con il nome della dir */
      ep = readdir(dp);
    }
    else{
      (*ls)[count++] = strdup(ep->d_name);
      ep = readdir(dp);
    }
  }
  (void)closedir(dp);
  return count;
}

---

What is the problem?
When i call the LIST cmd the 1st time it is all ok but when i call it the 2nd time the files is partially sent and i don't know why O.o

Why do you think a short write is a fatal error? Why aren't you trying to resend the unsent portion?

With this it doesn't works :(

Code:

---

send_again:
    rc_list = sendfile(newsockd, fpl, &offset_list, fileStat.st_size);
    if(rc_list == -1){
      perror("Invio file list non riuscito");
      onexit(newsockd, sockd, fpl, 3);
    }
    if((uint32_t)rc_list != fsize){
      fprintf(stderr, "Trasferimento incompleto: %d di %d bytes inviati\n", rc_list, (int)fileStat.st_size);
      goto send_again;
      //onexit(newsockd, sockd, fpl, 3);
    }

---

If send() doesn't send all your data then you are not supposed to resend everything.
You are supposed to keep sending until all your data is transmitted.
Meaning after a part of your data was sent, send the data from the offset that send has returned.
Kurt

It should be something like this

Code:

---

do {
  n = send(sock,buff,remainder);
  if ( n > 0 ) {
    buff  += n;
    remainder -= n;
  } else
  if ( n == 0 ) {
    // remote disconnected
  } else {
    // some error
    // EAGAIN isn't fatal if the socket is non-blocking
  }
} while ( remainder > 0 );

---

It advances through the buffer until it has been consumed, or something went wrong.

i've solved :D
the problem was that i have to put offset_list = 0; BEFORE every call to sendfile :)