Two comments inline, otherwise OK.
- todd
On Thu, 09 Oct 2014 14:52:50 +1000, David Gwynne wrote:
> Index: net/rcmd.c
> ===================================================================
> RCS file: /cvs/src/lib/libc/net/rcmd.c,v
> retrieving revision 1.56
> diff -u -p -r1.56 rcmd.c
> --- net/rcmd.c 18 Nov 2009 07:43:22 -0000 1.56
> +++ net/rcmd.c 9 Oct 2014 04:49:30 -0000
> @@ -46,6 +46,7 @@
> #include <string.h>
> #include <syslog.h>
> #include <stdlib.h>
> +#include <poll.h>
>
> int
> rcmd(char **ahost, int rport, const char *locuser, const char *remuser,
> @@ -63,7 +64,6 @@ rcmd_af(char **ahost, int porta, const c
> struct addrinfo hints, *res, *r;
> int error;
> struct sockaddr_storage from;
> - fd_set *readsp = NULL;
> sigset_t oldmask, mask;
> pid_t pid;
> int s, lport, timo;
> @@ -188,18 +188,14 @@ rcmd_af(char **ahost, int porta, const c
> write(s, "", 1);
> lport = 0;
> } else {
> + struct pollfd pfd[2];
> char num[8];
> int s2 = rresvport_af(&lport, af), s3;
> socklen_t len = sizeof(from);
> - int fdssize = howmany(MAX(s, s2)+1, NFDBITS) * sizeof(fd_mask);
>
> if (s2 < 0)
> goto bad;
> - readsp = (fd_set *)malloc(fdssize);
> - if (readsp == NULL) {
> - close(s2);
> - goto bad;
> - }
> +
> listen(s2, 1);
> (void)snprintf(num, sizeof(num), "%d", lport);
> if (write(s, num, strlen(num)+1) != strlen(num)+1) {
> @@ -210,12 +206,15 @@ rcmd_af(char **ahost, int porta, const c
> goto bad;
> }
> again:
> - bzero(readsp, fdssize);
> - FD_SET(s, readsp);
> - FD_SET(s2, readsp);
> + memset(pfd, 0, sizeof(pfd));
This memset is not needed, poll(2) will zero revents as needed.
Unused poll structs just need to have their fd set to -1 (not 0).
> + pfd[0].fd = s;
> + pfd[0].events = POLLIN;
> + pfd[1].fd = s2;
> + pfd[1].events = POLLIN;
> +
> errno = 0;
> - if (select(MAX(s, s2) + 1, readsp, 0, 0, 0) < 1 ||
> - !FD_ISSET(s2, readsp)) {
> + if (poll(pfd, 2, INFTIM) < 1 ||
> + (pfd[1].revents & POLLIN) == 0) {
You need to check for POLLIN|POLLHUP for this to be equivalent to
the select version.
> if (errno != 0)
> (void)fprintf(stderr,
> "rcmd: select (setting up stderr): %s\n",
> @@ -288,14 +287,11 @@ again:
> goto bad2;
> }
> sigprocmask(SIG_SETMASK, &oldmask, NULL);
> - free(readsp);
> return (s);
> bad2:
> if (lport)
> (void)close(*fd2p);
> bad:
> - if (readsp)
> - free(readsp);
> (void)close(s);
> sigprocmask(SIG_SETMASK, &oldmask, NULL);
> return (-1);
>
