Re: bin/59865: ftp should not set socket send/receive buffers unless told to

[gnats-admin%netbsd.org@localhost]

The following reply was made to PR bin/59865; it has been noted by GNATS.

From: mlelstv%serpens.de@localhost (Michael van Elst)
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: bin/59865: ftp should not set socket send/receive buffers unless told to
Date: Sat, 27 Dec 2025 13:06:32 -0000 (UTC)

 gnats-admin%netbsd.org@localhost writes:
 
 > > From: mlelstv%serpens.de@localhost (Michael van Elst)
 > >  N.B. configuring a socket buffer size and using the same value for
 > >  the size of I/O operations, as done by ftp, isn't optimal either. But
 > >  that's a different issue.
 > 
 > Yes, absolutely.
 
 
 I'm currently limiting the I/O buffer to 128kB as a compromise between
 file I/O and network buffer usage:
 
 Index: usr.bin/ftp/fetch.c
 ===================================================================
 RCS file: /cvsroot/src/usr.bin/ftp/fetch.c,v
 retrieving revision 1.242
 diff -p -u -r1.242 fetch.c
 --- usr.bin/ftp/fetch.c 29 Nov 2024 04:31:57 -0000      1.242
 +++ usr.bin/ftp/fetch.c 27 Dec 2025 13:00:19 -0000
 @@ -1697,10 +1697,12 @@ fetch_url(const char *url, const char *p
         oldint = xsignal(SIGINT, aborthttp);
  
         assert(rcvbuf_size > 0);
 -       if ((size_t)rcvbuf_size > bufsize) {
 +       if ((size_t)rcvbuf_size != bufsize) {
                 if (xferbuf)
                         (void)free(xferbuf);
                 bufsize = rcvbuf_size;
 +               if (bufsize > 128 * 1024)
 +                       bufsize = 128 * 1024;
                 xferbuf = ftp_malloc(bufsize);
         }
  
 Index: usr.bin/ftp/ftp.c
 ===================================================================
 RCS file: /cvsroot/src/usr.bin/ftp/ftp.c,v
 retrieving revision 1.179
 diff -p -u -r1.179 ftp.c
 --- usr.bin/ftp/ftp.c   6 Dec 2025 06:20:23 -0000       1.179
 +++ usr.bin/ftp/ftp.c   27 Dec 2025 13:00:19 -0000
 @@ -1085,10 +1085,12 @@ recvrequest(const char *cmd, char *volat
                 preserve = 0;
         }
         assert(rcvbuf_size > 0);
 -       if ((size_t)rcvbuf_size > bufsize) {
 +       if ((size_t)rcvbuf_size != bufsize) {
                 if (buf)
                         (void)free(buf);
                 bufsize = rcvbuf_size;
 +               if (bufsize > 128 * 1024)
 +                       bufsize = 128 * 1024;
                 buf = ftp_malloc(bufsize);
         }