tyler.durden
/
openssh-portable
mirror of https://github.com/PowerShell/openssh-portable.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

upstream: prepare for conversion of ssh, sshd mainloop from 

select() to poll() by moving FD_SET construction out of channel handlers into
separate functions. ok markus

OpenBSD-Commit-ID: 937fbf2a4de12b19fb9d5168424e206124807027
This commit is contained in:
djm@openbsd.org 2022-01-06 21:46:23 +00:00 committed by Damien Miller
parent 24c5187edf
commit 5c79952dfe
2 changed files with 139 additions and 83 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

210
channels.c
View File

@ -1,4 +1,4 @@
/* $OpenBSD: channels.c,v 1.409 2022/01/01 01:55:30 jsg Exp $ */
/* $OpenBSD: channels.c,v 1.410 2022/01/06 21:46:23 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -99,8 +99,7 @@
#define MAX_DISPLAYS 1000
/* Per-channel callback for pre/post select() actions */
typedef void chan_fn(struct ssh *, Channel *c,
fd_set *readset, fd_set *writeset);
typedef void chan_fn(struct ssh *, Channel *c);
/*
* Data structure for storing which hosts are permitted for forward requests.
@ -1096,33 +1095,31 @@ channel_set_fds(struct ssh *ssh, int id, int rfd, int wfd, int efd,
}
static void
channel_pre_listener(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_pre_listener(struct ssh *ssh, Channel *c)
{
FD_SET(c->sock, readset);
c->io_want = SSH_CHAN_IO_SOCK_R;
}
static void
channel_pre_connecting(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_pre_connecting(struct ssh *ssh, Channel *c)
{
debug3("channel %d: waiting for connection", c->self);
FD_SET(c->sock, writeset);
c->io_want = SSH_CHAN_IO_SOCK_W;
}
static void
channel_pre_open(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_pre_open(struct ssh *ssh, Channel *c)
{
c->io_want = 0;
if (c->istate == CHAN_INPUT_OPEN &&
c->remote_window > 0 &&
sshbuf_len(c->input) < c->remote_window &&
sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
FD_SET(c->rfd, readset);
c->io_want |= SSH_CHAN_IO_RFD;
if (c->ostate == CHAN_OUTPUT_OPEN ||
c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
if (sshbuf_len(c->output) > 0) {
FD_SET(c->wfd, writeset);
c->io_want |= SSH_CHAN_IO_WFD;
} else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
debug2("channel %d: "
@ -1137,12 +1134,12 @@ channel_pre_open(struct ssh *ssh, Channel *c,
c->ostate == CHAN_OUTPUT_CLOSED)) {
if (c->extended_usage == CHAN_EXTENDED_WRITE &&
sshbuf_len(c->extended) > 0)
FD_SET(c->efd, writeset);
c->io_want |= SSH_CHAN_IO_EFD_W;
else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
(c->extended_usage == CHAN_EXTENDED_READ ||
c->extended_usage == CHAN_EXTENDED_IGNORE) &&
sshbuf_len(c->extended) < c->remote_window)
FD_SET(c->efd, readset);
c->io_want |= SSH_CHAN_IO_EFD_R;
}
/* XXX: What about efd? races? */
}
@ -1224,8 +1221,7 @@ x11_open_helper(struct ssh *ssh, struct sshbuf *b)
}
static void
channel_pre_x11_open(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_pre_x11_open(struct ssh *ssh, Channel *c)
{
int ret = x11_open_helper(ssh, c->output);
@ -1233,7 +1229,7 @@ channel_pre_x11_open(struct ssh *ssh, Channel *c,
if (ret == 1) {
c->type = SSH_CHANNEL_OPEN;
channel_pre_open(ssh, c, readset, writeset);
channel_pre_open(ssh, c);
} else if (ret == -1) {
logit("X11 connection rejected because of wrong authentication.");
debug2("X11 rejected %d i%d/o%d",
@ -1248,12 +1244,12 @@ channel_pre_x11_open(struct ssh *ssh, Channel *c,
}
static void
channel_pre_mux_client(struct ssh *ssh,
Channel *c, fd_set *readset, fd_set *writeset)
channel_pre_mux_client(struct ssh *ssh, Channel *c)
{
c->io_want = 0;
if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
FD_SET(c->rfd, readset);
c->io_want |= SSH_CHAN_IO_RFD;
if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
/* clear buffer immediately (discard any partial packet) */
sshbuf_reset(c->input);
@ -1264,7 +1260,7 @@ channel_pre_mux_client(struct ssh *ssh,
if (c->ostate == CHAN_OUTPUT_OPEN ||
c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
if (sshbuf_len(c->output) > 0)
FD_SET(c->wfd, writeset);
c->io_want |= SSH_CHAN_IO_WFD;
else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
chan_obuf_empty(ssh, c);
}
@ -1543,20 +1539,20 @@ channel_connect_stdio_fwd(struct ssh *ssh,
/* dynamic port forwarding */
static void
channel_pre_dynamic(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_pre_dynamic(struct ssh *ssh, Channel *c)
{
const u_char *p;
u_int have;
int ret;
c->io_want = 0;
have = sshbuf_len(c->input);
debug2("channel %d: pre_dynamic: have %d", c->self, have);
/* sshbuf_dump(c->input, stderr); */
/* check if the fixed size part of the packet is in buffer. */
if (have < 3) {
/* need more */
FD_SET(c->sock, readset);
c->io_want |= SSH_CHAN_IO_RFD;
return;
}
/* try to guess the protocol */
@ -1578,9 +1574,9 @@ channel_pre_dynamic(struct ssh *ssh, Channel *c,
} else if (ret == 0) {
debug2("channel %d: pre_dynamic: need more", c->self);
/* need more */
FD_SET(c->sock, readset);
c->io_want |= SSH_CHAN_IO_RFD;
if (sshbuf_len(c->output))
FD_SET(c->sock, writeset);
c->io_want |= SSH_CHAN_IO_WFD;
} else {
/* switch to the next state */
c->type = SSH_CHANNEL_OPENING;
@ -1660,8 +1656,7 @@ channel_before_prepare_select_rdynamic(struct ssh *ssh, Channel *c)
/* This is our fake X11 server socket. */
static void
channel_post_x11_listener(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_post_x11_listener(struct ssh *ssh, Channel *c)
{
Channel *nc;
struct sockaddr_storage addr;
@ -1669,7 +1664,7 @@ channel_post_x11_listener(struct ssh *ssh, Channel *c,
socklen_t addrlen;
char buf[16384], *remote_ipaddr;
if (!FD_ISSET(c->sock, readset))
if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
return;
debug("X11 connection requested.");
@ -1778,8 +1773,7 @@ channel_set_x11_refuse_time(struct ssh *ssh, u_int refuse_time)
* This socket is listening for connections to a forwarded TCP/IP port.
*/
static void
channel_post_port_listener(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_post_port_listener(struct ssh *ssh, Channel *c)
{
Channel *nc;
struct sockaddr_storage addr;
@ -1787,7 +1781,7 @@ channel_post_port_listener(struct ssh *ssh, Channel *c,
socklen_t addrlen;
char *rtype;
if (!FD_ISSET(c->sock, readset))
if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
return;
debug("Connection to port %d forwarding to %.100s port %d requested.",
@ -1838,15 +1832,14 @@ channel_post_port_listener(struct ssh *ssh, Channel *c,
* clients.
*/
static void
channel_post_auth_listener(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_post_auth_listener(struct ssh *ssh, Channel *c)
{
Channel *nc;
int r, newsock;
struct sockaddr_storage addr;
socklen_t addrlen;
if (!FD_ISSET(c->sock, readset))
if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
return;
addrlen = sizeof(addr);
@ -1867,13 +1860,12 @@ channel_post_auth_listener(struct ssh *ssh, Channel *c,
}
static void
channel_post_connecting(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_post_connecting(struct ssh *ssh, Channel *c)
{
int err = 0, sock, isopen, r;
socklen_t sz = sizeof(err);
if (!FD_ISSET(c->sock, writeset))
if ((c->io_ready & SSH_CHAN_IO_SOCK_W) == 0)
return;
if (!c->have_remote_id)
fatal_f("channel %d: no remote id", c->self);
@ -1932,8 +1924,7 @@ channel_post_connecting(struct ssh *ssh, Channel *c,
}
static int
channel_handle_rfd(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_handle_rfd(struct ssh *ssh, Channel *c)
{
char buf[CHAN_RBUF];
ssize_t len;
@ -1941,7 +1932,7 @@ channel_handle_rfd(struct ssh *ssh, Channel *c,
force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
if (c->rfd == -1 || (!force && !FD_ISSET(c->rfd, readset)))
if ((c->io_ready & SSH_CHAN_IO_RFD) == 0)
return 1;
errno = 0;
@ -1980,16 +1971,16 @@ channel_handle_rfd(struct ssh *ssh, Channel *c,
}
static int
channel_handle_wfd(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_handle_wfd(struct ssh *ssh, Channel *c)
{
struct termios tio;
u_char *data = NULL, *buf; /* XXX const; need filter API change */
size_t dlen, olen = 0;
int r, len;
if (c->wfd == -1 || !FD_ISSET(c->wfd, writeset) ||
sshbuf_len(c->output) == 0)
if ((c->io_ready & SSH_CHAN_IO_WFD) == 0)
return 1;
if (sshbuf_len(c->output) == 0)
return 1;
/* Send buffered output data to the socket. */
@ -2070,13 +2061,14 @@ channel_handle_wfd(struct ssh *ssh, Channel *c,
}
static int
channel_handle_efd_write(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_handle_efd_write(struct ssh *ssh, Channel *c)
{
int r;
ssize_t len;
if (!FD_ISSET(c->efd, writeset) || sshbuf_len(c->extended) == 0)
if ((c->io_ready & SSH_CHAN_IO_EFD_W) == 0)
return 1;
if (sshbuf_len(c->extended) == 0)
return 1;
len = write(c->efd, sshbuf_ptr(c->extended),
@ -2097,8 +2089,7 @@ channel_handle_efd_write(struct ssh *ssh, Channel *c,
}
static int
channel_handle_efd_read(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_handle_efd_read(struct ssh *ssh, Channel *c)
{
char buf[CHAN_RBUF];
ssize_t len;
@ -2106,7 +2097,7 @@ channel_handle_efd_read(struct ssh *ssh, Channel *c,
force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
if (c->efd == -1 || (!force && !FD_ISSET(c->efd, readset)))
if ((c->io_ready & SSH_CHAN_IO_EFD_R) == 0)
return 1;
len = read(c->efd, buf, sizeof(buf));
@ -2125,8 +2116,7 @@ channel_handle_efd_read(struct ssh *ssh, Channel *c,
}
static int
channel_handle_efd(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_handle_efd(struct ssh *ssh, Channel *c)
{
if (c->efd == -1)
return 1;
@ -2134,10 +2124,10 @@ channel_handle_efd(struct ssh *ssh, Channel *c,
/** XXX handle drain efd, too */
if (c->extended_usage == CHAN_EXTENDED_WRITE)
return channel_handle_efd_write(ssh, c, readset, writeset);
return channel_handle_efd_write(ssh, c);
else if (c->extended_usage == CHAN_EXTENDED_READ ||
c->extended_usage == CHAN_EXTENDED_IGNORE)
return channel_handle_efd_read(ssh, c, readset, writeset);
return channel_handle_efd_read(ssh, c);
return 1;
}
@ -2171,12 +2161,11 @@ channel_check_window(struct ssh *ssh, Channel *c)
}
static void
channel_post_open(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_post_open(struct ssh *ssh, Channel *c)
{
channel_handle_rfd(ssh, c, readset, writeset);
channel_handle_wfd(ssh, c, readset, writeset);
channel_handle_efd(ssh, c, readset, writeset);
channel_handle_rfd(ssh, c);
channel_handle_wfd(ssh, c);
channel_handle_efd(ssh, c);
channel_check_window(ssh, c);
}
@ -2205,12 +2194,11 @@ read_mux(struct ssh *ssh, Channel *c, u_int need)
}
static void
channel_post_mux_client_read(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_post_mux_client_read(struct ssh *ssh, Channel *c)
{
u_int need;
if (c->rfd == -1 || !FD_ISSET(c->rfd, readset))
if ((c->io_ready & SSH_CHAN_IO_RFD) == 0)
return;
if (c->istate != CHAN_INPUT_OPEN && c->istate != CHAN_INPUT_WAIT_DRAIN)
return;
@ -2242,14 +2230,14 @@ channel_post_mux_client_read(struct ssh *ssh, Channel *c,
}
static void
channel_post_mux_client_write(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_post_mux_client_write(struct ssh *ssh, Channel *c)
{
ssize_t len;
int r;
if (c->wfd == -1 || !FD_ISSET(c->wfd, writeset) ||
sshbuf_len(c->output) == 0)
if ((c->io_ready & SSH_CHAN_IO_WFD) == 0)
return;
if (sshbuf_len(c->output) == 0)
return;
len = write(c->wfd, sshbuf_ptr(c->output), sshbuf_len(c->output));
@ -2264,16 +2252,14 @@ channel_post_mux_client_write(struct ssh *ssh, Channel *c,
}
static void
channel_post_mux_client(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_post_mux_client(struct ssh *ssh, Channel *c)
{
channel_post_mux_client_read(ssh, c, readset, writeset);
channel_post_mux_client_write(ssh, c, readset, writeset);
channel_post_mux_client_read(ssh, c);
channel_post_mux_client_write(ssh, c);
}
static void
channel_post_mux_listener(struct ssh *ssh, Channel *c,
fd_set *readset, fd_set *writeset)
channel_post_mux_listener(struct ssh *ssh, Channel *c)
{
Channel *nc;
struct sockaddr_storage addr;
@ -2282,7 +2268,7 @@ channel_post_mux_listener(struct ssh *ssh, Channel *c,
uid_t euid;
gid_t egid;
if (!FD_ISSET(c->sock, readset))
if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
return;
debug("multiplexing control connection");
@ -2388,8 +2374,7 @@ channel_garbage_collect(struct ssh *ssh, Channel *c)
enum channel_table { CHAN_PRE, CHAN_POST };
static void
channel_handler(struct ssh *ssh, int table,
fd_set *readset, fd_set *writeset, time_t *unpause_secs)
channel_handler(struct ssh *ssh, int table, time_t *unpause_secs)
{
struct ssh_channels *sc = ssh->chanctxt;
chan_fn **ftab = table == CHAN_PRE ? sc->channel_pre : sc->channel_post;
@ -2415,7 +2400,7 @@ channel_handler(struct ssh *ssh, int table,
* Run handlers that are not paused.
*/
if (c->notbefore <= now)
(*ftab[c->type])(ssh, c, readset, writeset);
(*ftab[c->type])(ssh, c);
else if (unpause_secs != NULL) {
/*
* Collect the time that the earliest
@ -2465,7 +2450,9 @@ void
channel_prepare_select(struct ssh *ssh, fd_set **readsetp, fd_set **writesetp,
int *maxfdp, u_int *nallocp, time_t *minwait_secs)
{
u_int n, sz, nfdset;
struct ssh_channels *sc = ssh->chanctxt;
u_int i, n, sz, nfdset, oalloc = sc->channels_alloc;
Channel *c;
channel_before_prepare_select(ssh); /* might update channel_max_fd */
@ -2488,8 +2475,44 @@ channel_prepare_select(struct ssh *ssh, fd_set **readsetp, fd_set **writesetp,
memset(*writesetp, 0, sz);
if (!ssh_packet_is_rekeying(ssh))
channel_handler(ssh, CHAN_PRE, *readsetp, *writesetp,
minwait_secs);
channel_handler(ssh, CHAN_PRE, minwait_secs);
/* Convert c->io_want into FD_SET */
for (i = 0; i < oalloc; i++) {
c = sc->channels[i];
if (c == NULL)
continue;
if ((c->io_want & SSH_CHAN_IO_RFD) != 0) {
if (c->rfd == -1)
fatal_f("channel %d: no rfd", c->self);
FD_SET(c->rfd, *readsetp);
}
if ((c->io_want & SSH_CHAN_IO_WFD) != 0) {
if (c->wfd == -1)
fatal_f("channel %d: no wfd", c->self);
FD_SET(c->wfd, *writesetp);
}
if ((c->io_want & SSH_CHAN_IO_EFD_R) != 0) {
if (c->efd == -1)
fatal_f("channel %d: no efd(r)", c->self);
FD_SET(c->efd, *readsetp);
}
if ((c->io_want & SSH_CHAN_IO_EFD_W) != 0) {
if (c->efd == -1)
fatal_f("channel %d: no efd(w)", c->self);
FD_SET(c->efd, *writesetp);
}
if ((c->io_want & SSH_CHAN_IO_SOCK_R) != 0) {
if (c->sock == -1)
fatal_f("channel %d: no sock(r)", c->self);
FD_SET(c->sock, *readsetp);
}
if ((c->io_want & SSH_CHAN_IO_SOCK_W) != 0) {
if (c->sock == -1)
fatal_f("channel %d: no sock(w)", c->self);
FD_SET(c->sock, *writesetp);
}
}
}
/*
@ -2499,7 +2522,30 @@ channel_prepare_select(struct ssh *ssh, fd_set **readsetp, fd_set **writesetp,
void
channel_after_select(struct ssh *ssh, fd_set *readset, fd_set *writeset)
{
channel_handler(ssh, CHAN_POST, readset, writeset, NULL);
struct ssh_channels *sc = ssh->chanctxt;
Channel *c;
u_int i, oalloc = sc->channels_alloc;
/* Convert FD_SET into c->io_ready */
for (i = 0; i < oalloc; i++) {
c = sc->channels[i];
if (c == NULL)
continue;
c->io_ready = 0;
if (c->rfd != -1 && FD_ISSET(c->rfd, readset))
c->io_ready |= SSH_CHAN_IO_RFD;
if (c->wfd != -1 && FD_ISSET(c->wfd, writeset))
c->io_ready |= SSH_CHAN_IO_WFD;
if (c->efd != -1 && FD_ISSET(c->efd, readset))
c->io_ready |= SSH_CHAN_IO_EFD_R;
if (c->efd != -1 && FD_ISSET(c->efd, writeset))
c->io_ready |= SSH_CHAN_IO_EFD_W;
if (c->sock != -1 && FD_ISSET(c->sock, readset))
c->io_ready |= SSH_CHAN_IO_SOCK_R;
if (c->sock != -1 && FD_ISSET(c->sock, writeset))
c->io_ready |= SSH_CHAN_IO_SOCK_W;
}
channel_handler(ssh, CHAN_POST, NULL);
}
/*

12
channels.h
View File

@ -1,4 +1,4 @@
/* $OpenBSD: channels.h,v 1.138 2021/05/19 01:24:05 djm Exp $ */
/* $OpenBSD: channels.h,v 1.139 2022/01/06 21:46:23 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
@ -136,6 +136,8 @@ struct Channel {
int wfd; /* write fd */
int efd; /* extended fd */
int sock; /* sock fd */
u_int io_want; /* bitmask of SSH_CHAN_IO_* */
u_int io_ready; /* bitmask of SSH_CHAN_IO_* */
int ctl_chan; /* control channel (multiplexed connections) */
int isatty; /* rfd is a tty */
#ifdef _AIX
@ -231,6 +233,14 @@ struct Channel {
#define CHAN_EOF_RCVD 0x08
#define CHAN_LOCAL 0x10
/* file descriptor events */
#define SSH_CHAN_IO_RFD 0x01
#define SSH_CHAN_IO_WFD 0x02
#define SSH_CHAN_IO_EFD_R 0x04
#define SSH_CHAN_IO_EFD_W 0x08
#define SSH_CHAN_IO_SOCK_R 0x10
#define SSH_CHAN_IO_SOCK_W 0x20
/* Read buffer size */
#define CHAN_RBUF (16*1024)