Convert from select() to ppoll(). Along the way, I observed that the

select() code was using exceptfds incorrectly..
ok millert

diff --git a/usr.bin/ssh/ssh-keyscan.c b/usr.bin/ssh/ssh-keyscan.c
index 222dbdf..19e267b 100644 (file)
--- a/usr.bin/ssh/ssh-keyscan.c
+++ b/usr.bin/ssh/ssh-keyscan.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keyscan.c,v 1.140 2021/10/02 03:17:01 dtucker Exp $ */
+/* $OpenBSD: ssh-keyscan.c,v 1.141 2021/11/11 15:32:32 deraadt Exp $ */
 /*
  * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
  *
@@ -22,6 +22,7 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <poll.h>
 #include <signal.h>
 #include <string.h>
 #include <unistd.h>
@@ -79,8 +80,7 @@ int maxfd;
 #define MAXCON (maxfd - 10)
 
 extern char *__progname;
-fd_set *read_wait;
-size_t read_wait_nfdset;
+struct pollfd *read_wait;
 int ncon;
 
 /*
@@ -105,7 +105,7 @@ typedef struct Connection {
        char *c_output_name;    /* Hostname of connection for output */
        char *c_data;           /* Data read from this fd */
        struct ssh *c_ssh;      /* SSH-connection */
-       struct timeval c_tv;    /* Time at which connection gets aborted */
+       struct timespec c_ts;   /* Time at which connection gets aborted */
        TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
 } con;
 
@@ -395,10 +395,11 @@ conalloc(char *iname, char *oname, int keytype)
        fdcon[s].c_len = 4;
        fdcon[s].c_off = 0;
        fdcon[s].c_keytype = keytype;
-       monotime_tv(&fdcon[s].c_tv);
-       fdcon[s].c_tv.tv_sec += timeout;
+       monotime_ts(&fdcon[s].c_ts);
+       fdcon[s].c_ts.tv_sec += timeout;
        TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
-       FD_SET(s, read_wait);
+       read_wait[s].fd = s;
+       read_wait[s].events = POLLIN;
        ncon++;
        return (s);
 }
@@ -421,7 +422,8 @@ confree(int s)
        } else
                close(s);
        TAILQ_REMOVE(&tq, &fdcon[s], c_link);
-       FD_CLR(s, read_wait);
+       read_wait[s].fd = -1;
+       read_wait[s].events = 0;
        ncon--;
 }
 
@@ -429,8 +431,8 @@ static void
 contouch(int s)
 {
        TAILQ_REMOVE(&tq, &fdcon[s], c_link);
-       monotime_tv(&fdcon[s].c_tv);
-       fdcon[s].c_tv.tv_sec += timeout;
+       monotime_ts(&fdcon[s].c_ts);
+       fdcon[s].c_ts.tv_sec += timeout;
        TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 }
 
@@ -558,40 +560,31 @@ conread(int s)
 static void
 conloop(void)
 {
-       struct timeval seltime, now;
-       fd_set *r, *e;
+       struct timespec seltime, now;
        con *c;
        int i;
 
-       monotime_tv(&now);
+       monotime_ts(&now);
        c = TAILQ_FIRST(&tq);
 
-       if (c && timercmp(&c->c_tv, &now, >))
-               timersub(&c->c_tv, &now, &seltime);
+       if (c && timespeccmp(&c->c_ts, &now, >))
+               timespecsub(&c->c_ts, &now, &seltime);
        else
-               timerclear(&seltime);
+               timespecclear(&seltime);
 
-       r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
-       e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
-       memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
-       memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
-
-       while (select(maxfd, r, NULL, e, &seltime) == -1 &&
+       while (ppoll(read_wait, maxfd, &seltime, NULL) == -1 &&
            (errno == EAGAIN || errno == EINTR))
                ;
 
        for (i = 0; i < maxfd; i++) {
-               if (FD_ISSET(i, e)) {
-                       error("%s: exception!", fdcon[i].c_name);
+               if (read_wait[i].revents & (POLLHUP|POLLERR|POLLNVAL))
                        confree(i);
-               } else if (FD_ISSET(i, r))
+               else if (read_wait[i].revents & POLLIN)
                        conread(i);
        }
-       free(r);
-       free(e);
 
        c = TAILQ_FIRST(&tq);
-       while (c && timercmp(&c->c_tv, &now, <)) {
+       while (c && timespeccmp(&c->c_ts, &now, <)) {
                int s = c->c_fd;
 
                c = TAILQ_NEXT(c, c_link);
@@ -759,9 +752,7 @@ main(int argc, char **argv)
        if (maxfd > fdlim_get(0))
                fdlim_set(maxfd);
        fdcon = xcalloc(maxfd, sizeof(con));
-
-       read_wait_nfdset = howmany(maxfd, NFDBITS);
-       read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
+       read_wait = xcalloc(maxfd, sizeof(struct pollfd));
 
        for (j = 0; j < fopt_count; j++) {
                if (argv[j] == NULL)