- markus@cvs.openbsd.org 2010/12/08 22:46:03

     [scp.1 scp.c]
     add a new -3 option to scp: Copies between two remote hosts are
     transferred through the local host.  Without this option the data
     is copied directly between the two remote hosts. ok djm@ (bugzilla #1837)

1 files changed, 86 insertions, 3 deletions

diff --git a/scp.c b/scp.c
index 774e602f2..1262e0aff 100644
--- a/scp.c
+++ b/scp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: scp.c,v 1.168 2010/11/26 05:52:49 djm Exp $ */
+/* $OpenBSD: scp.c,v 1.169 2010/12/08 22:46:03 markus Exp $ */
 /*
  * scp - secure remote copy.  This is basically patched BSD rcp which
  * uses ssh to do the data transfer (instead of using rcmd).
@@ -119,6 +119,7 @@ extern char *__progname;
 #define COPY_BUFLEN     16384
 
 int do_cmd(char *host, char *remuser, char *cmd, int *fdin, int *fdout);
+int do_cmd2(char *host, char *remuser, char *cmd, int fdin, int fdout);
 
 /* Struct for addargs */
 arglist args;
@@ -137,6 +138,12 @@ int verbose_mode = 0;
 /* This is set to zero if the progressmeter is not desired. */
 int showprogress = 1;
 
+/*
+ * This is set to non-zero if remote-remote copy should be piped
+ * through this process.
+ */
+int throughlocal = 0;
+
 /* This is the program to execute for the secured connection. ("ssh" or -S) */
 char *ssh_program = _PATH_SSH_PROGRAM;
 
@@ -287,6 +294,50 @@ do_cmd(char *host, char *remuser, char *cmd, int *fdin, int *fdout)
         return 0;
 }
 
+/*
+ * This functions executes a command simlar to do_cmd(), but expects the
+ * input and output descriptors to be setup by a previous call to do_cmd().
+ * This way the input and output of two commands can be connected.
+ */
+int
+do_cmd2(char *host, char *remuser, char *cmd, int fdin, int fdout)
+{
+        pid_t pid;
+        int status;
+
+        if (verbose_mode)
+                fprintf(stderr,
+                    "Executing: 2nd program %s host %s, user %s, command %s\n",
+                    ssh_program, host,
+                    remuser ? remuser : "(unspecified)", cmd);
+
+        /* Fork a child to execute the command on the remote host using ssh. */
+        pid = fork();
+        if (pid == 0) {
+                dup2(fdin, 0);
+                dup2(fdout, 1);
+
+                replacearg(&args, 0, "%s", ssh_program);
+                if (remuser != NULL) {
+                        addargs(&args, "-l");
+                        addargs(&args, "%s", remuser);
+                }
+                addargs(&args, "--");
+                addargs(&args, "%s", host);
+                addargs(&args, "%s", cmd);
+
+                execvp(ssh_program, args.list);
+                perror(ssh_program);
+                exit(1);
+        } else if (pid == -1) {
+                fatal("fork: %s", strerror(errno));
+        }
+        while (waitpid(pid, &status, 0) == -1)
+                if (errno != EINTR)
+                        fatal("do_cmd2: waitpid: %s", strerror(errno));
+        return 0;
+}
+
 typedef struct {
         size_t cnt;
         char *buf;
@@ -344,7 +395,7 @@ main(int argc, char **argv)
         addargs(&args, "-oClearAllForwardings=yes");
 
         fflag = tflag = 0;
-        while ((ch = getopt(argc, argv, "dfl:prtvBCc:i:P:q1246S:o:F:")) != -1)
+        while ((ch = getopt(argc, argv, "dfl:prtvBCc:i:P:q12346S:o:F:")) != -1)
                 switch (ch) {
                 /* User-visible flags. */
                 case '1':
@@ -355,6 +406,9 @@ main(int argc, char **argv)
                         addargs(&args, "-%c", ch);
                         addargs(&remote_remote_args, "-%c", ch);
                         break;
+                case '3':
+                        throughlocal = 1;
+                        break;
                 case 'o':
                 case 'c':
                 case 'i':
@@ -530,7 +584,36 @@ toremote(char *targ, int argc, char **argv)
 
         for (i = 0; i < argc - 1; i++) {
                 src = colon(argv[i]);
-                if (src) {      /* remote to remote */
+                if (src && throughlocal) {      /* extended remote to remote */
+                        *src++ = 0;
+                        if (*src == 0)
+                                src = ".";
+                        host = strrchr(argv[i], '@');
+                        if (host) {
+                                *host++ = 0;
+                                host = cleanhostname(host);
+                                suser = argv[i];
+                                if (*suser == '\0')
+                                        suser = pwd->pw_name;
+                                else if (!okname(suser))
+                                        continue;
+                        } else {
+                                host = cleanhostname(argv[i]);
+                                suser = NULL;
+                        }
+                        xasprintf(&bp, "%s -f -- %s", cmd, src);
+                        if (do_cmd(host, suser, bp, &remin, &remout) < 0)
+                                exit(1);
+                        (void) xfree(bp);
+                        host = cleanhostname(thost);
+                        xasprintf(&bp, "%s -t -- %s", cmd, targ);
+                        if (do_cmd2(host, tuser, bp, remin, remout) < 0)
+                                exit(1);
+                        (void) xfree(bp);
+                        (void) close(remin);
+                        (void) close(remout);
+                        remin = remout = -1;
+                } else if (src) {       /* standard remote to remote */
                         freeargs(&alist);
                         addargs(&alist, "%s", ssh_program);
                         addargs(&alist, "-x");