summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authormillert@openbsd.org <millert@openbsd.org>2023-01-10 23:22:15 +0000
committerDamien Miller <djm@mindrot.org>2023-01-11 11:43:17 +1100
commiteec737b59cf13841de46134967a206607000acd4 (patch)
tree90f5e1b07f76f9b9e93e8988533f598b8b71407c
parentd213d126a4a343abd3a1eb13687d39c1891fe5c8 (diff)
upstream: Switch scp from using pipes to a socketpair for
communication with it's ssh sub-processes. We no longer need to reserve two descriptors to ensure that we don't end up using fd 0-2 unexpectedly, that is handled by sanitise_stdfd() in main(). Based on an original diff from djm@. OK deraadt@ djm@ OpenBSD-Commit-ID: b80c372faac462471e955ddeab9480d668a2e48d
-rw-r--r--scp.c62
1 files changed, 25 insertions, 37 deletions
diff --git a/scp.c b/scp.c
index 93ac8ed7..42cd034b 100644
--- a/scp.c
+++ b/scp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: scp.c,v 1.251 2022/12/16 06:52:48 jmc Exp $ */
+/* $OpenBSD: scp.c,v 1.252 2023/01/10 23:22:15 millert Exp $ */
/*
* scp - secure remote copy. This is basically patched BSD rcp which
* uses ssh to do the data transfer (instead of using rcmd).
@@ -279,7 +279,7 @@ int
do_cmd(char *program, char *host, char *remuser, int port, int subsystem,
char *cmd, int *fdin, int *fdout, pid_t *pid)
{
- int pin[2], pout[2], reserved[2];
+ int sv[2];
if (verbose_mode)
fmprintf(stderr,
@@ -290,22 +290,9 @@ do_cmd(char *program, char *host, char *remuser, int port, int subsystem,
if (port == -1)
port = sshport;
- /*
- * Reserve two descriptors so that the real pipes won't get
- * descriptors 0 and 1 because that will screw up dup2 below.
- */
- if (pipe(reserved) == -1)
- fatal("pipe: %s", strerror(errno));
-
/* Create a socket pair for communicating with ssh. */
- if (pipe(pin) == -1)
- fatal("pipe: %s", strerror(errno));
- if (pipe(pout) == -1)
- fatal("pipe: %s", strerror(errno));
-
- /* Free the reserved descriptors. */
- close(reserved[0]);
- close(reserved[1]);
+ if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == -1)
+ fatal("socketpair: %s", strerror(errno));
ssh_signal(SIGTSTP, suspchild);
ssh_signal(SIGTTIN, suspchild);
@@ -313,15 +300,18 @@ do_cmd(char *program, char *host, char *remuser, int port, int subsystem,
/* Fork a child to execute the command on the remote host using ssh. */
*pid = fork();
- if (*pid == 0) {
+ switch (*pid) {
+ case -1:
+ fatal("fork: %s", strerror(errno));
+ case 0:
/* Child. */
- close(pin[1]);
- close(pout[0]);
- dup2(pin[0], 0);
- dup2(pout[1], 1);
- close(pin[0]);
- close(pout[1]);
-
+ if (dup2(sv[0], STDIN_FILENO) == -1 ||
+ dup2(sv[0], STDOUT_FILENO) == -1) {
+ perror("dup2");
+ _exit(1);
+ }
+ close(sv[0]);
+ close(sv[1]);
replacearg(&args, 0, "%s", program);
if (port != -1) {
addargs(&args, "-p");
@@ -339,19 +329,17 @@ do_cmd(char *program, char *host, char *remuser, int port, int subsystem,
execvp(program, args.list);
perror(program);
- exit(1);
- } else if (*pid == -1) {
- fatal("fork: %s", strerror(errno));
+ _exit(1);
+ default:
+ /* Parent. Close the other side, and return the local side. */
+ close(sv[0]);
+ *fdin = sv[1];
+ *fdout = sv[1];
+ ssh_signal(SIGTERM, killchild);
+ ssh_signal(SIGINT, killchild);
+ ssh_signal(SIGHUP, killchild);
+ return 0;
}
- /* Parent. Close the other side, and return the local side. */
- close(pin[0]);
- *fdout = pin[1];
- close(pout[1]);
- *fdin = pout[0];
- ssh_signal(SIGTERM, killchild);
- ssh_signal(SIGINT, killchild);
- ssh_signal(SIGHUP, killchild);
- return 0;
}
/*