diff options
Diffstat (limited to 'channels.c')
| -rw-r--r-- | channels.c | 40 |
1 files changed, 31 insertions, 9 deletions
diff --git a/channels.c b/channels.c index a23fde425f37..bfe2e3b2d4f7 100644 --- a/channels.c +++ b/channels.c @@ -1,4 +1,4 @@ -/* $OpenBSD: channels.c,v 1.439 2024/07/25 22:40:08 djm Exp $ */ +/* $OpenBSD: channels.c,v 1.442 2024/12/05 06:49:26 dtucker Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -94,6 +94,8 @@ #define NUM_SOCKS 10 /* -- X11 forwarding */ +/* X11 port for display :0 */ +#define X11_BASE_PORT 6000 /* Maximum number of fake X11 displays to try. */ #define MAX_DISPLAYS 1000 @@ -4998,19 +5000,19 @@ x11_create_display_inet(struct ssh *ssh, int x11_display_offset, u_int *display_numberp, int **chanids) { Channel *nc = NULL; - int display_number, sock; - u_short port; + int display_number, sock, port; struct addrinfo hints, *ai, *aitop; char strport[NI_MAXSERV]; int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; - if (chanids == NULL) + if (chanids == NULL || x11_display_offset < 0 || + x11_display_offset > UINT16_MAX - X11_BASE_PORT - MAX_DISPLAYS) return -1; for (display_number = x11_display_offset; display_number < MAX_DISPLAYS; display_number++) { - port = 6000 + display_number; + port = X11_BASE_PORT + display_number; memset(&hints, 0, sizeof(hints)); hints.ai_family = ssh->chanctxt->IPv4or6; hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE; @@ -5226,7 +5228,8 @@ x11_connect_display(struct ssh *ssh) * buf now contains the host name. But first we parse the * display number. */ - if (sscanf(cp + 1, "%u", &display_number) != 1) { + if (sscanf(cp + 1, "%u", &display_number) != 1 || + display_number > UINT16_MAX - X11_BASE_PORT) { error("Could not parse display number from DISPLAY: %.100s", display); return -1; @@ -5236,7 +5239,7 @@ x11_connect_display(struct ssh *ssh) memset(&hints, 0, sizeof(hints)); hints.ai_family = ssh->chanctxt->IPv4or6; hints.ai_socktype = SOCK_STREAM; - snprintf(strport, sizeof strport, "%u", 6000 + display_number); + snprintf(strport, sizeof strport, "%u", X11_BASE_PORT + display_number); if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { error("%.100s: unknown host. (%s)", buf, ssh_gai_strerror(gaierr)); @@ -5252,7 +5255,7 @@ x11_connect_display(struct ssh *ssh) /* Connect it to the display. */ if (connect(sock, ai->ai_addr, ai->ai_addrlen) == -1) { debug2("connect %.100s port %u: %.100s", buf, - 6000 + display_number, strerror(errno)); + X11_BASE_PORT + display_number, strerror(errno)); close(sock); continue; } @@ -5262,7 +5265,7 @@ x11_connect_display(struct ssh *ssh) freeaddrinfo(aitop); if (!ai) { error("connect %.100s port %u: %.100s", buf, - 6000 + display_number, strerror(errno)); + X11_BASE_PORT + display_number, strerror(errno)); return -1; } set_nodelay(sock); @@ -5336,3 +5339,22 @@ x11_request_forwarding_with_spoofing(struct ssh *ssh, int client_session_id, fatal_fr(r, "send x11-req"); free(new_data); } + +/* + * Returns whether an x11 channel was used recently (less than a second ago) + */ +int +x11_channel_used_recently(struct ssh *ssh) { + u_int i; + Channel *c; + time_t lastused = 0; + + for (i = 0; i < ssh->chanctxt->channels_alloc; i++) { + c = ssh->chanctxt->channels[i]; + if (c == NULL || c->ctype == NULL || c->lastused == 0 || + strcmp(c->ctype, "x11-connection") != 0) + continue; + lastused = c->lastused; + } + return lastused != 0 && monotime() > lastused + 1; +} |