From: Chris Turner <c.turner@199technologies.com>
Date: Wed, 12 Sep 2012 13:11:31 +0000 (+0000)
Subject: hammer(8): add HAMMER_RSH environment variable support.
X-Git-Tag: v3.2.0~167
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/e2c596b1a494dc77d2e42a43f4bd5ad414d20320

hammer(8): add HAMMER_RSH environment variable support.

Add support for a HAMMER_RSH environment variable which can be used
to select an alternate remote shell to be used for hammer remote operations,
change remote shell invocation to rsh(1) style '-l user host' instead of
ssh-style user@host to permit usage of rsh(1) as an alternate HAMMER_RSH
without the need for a wrapper script. Also change exec call of subshell
to use execvp instead of a hardcoded path to facillitate this change.

Update hammer.8 docs, along with minor formatting fix to environment
variable summary header sentence.
---

diff --git a/sbin/hammer/cmd_mirror.c b/sbin/hammer/cmd_mirror.c
index 918c528ce6..a3039be78a 100644
--- a/sbin/hammer/cmd_mirror.c
+++ b/sbin/hammer/cmd_mirror.c
@@ -1053,7 +1053,7 @@ hammer_cmd_mirror_copy(char **av, int ac, int streaming)
 	int fds[2];
 	const char *xav[32];
 	char tbuf[16];
-	char *ptr;
+	char *sh, *user, *host, *rfs;
 	int xac;
 
 	if (ac != 2)
@@ -1077,17 +1077,38 @@ again:
 		dup2(fds[0], 1);
 		close(fds[0]);
 		close(fds[1]);
-		if ((ptr = strchr(av[0], ':')) != NULL) {
-			*ptr++ = 0;
+		if ((rfs = strchr(av[0], ':')) != NULL) {
 			xac = 0;
-			xav[xac++] = "ssh";
+
+			if((sh = getenv("HAMMER_RSH")) == NULL)
+				xav[xac++] = "ssh";
+			else
+				xav[xac++] = sh;
+
 			if (CompressOpt)
 				xav[xac++] = "-C";
+
+			user = strndup(av[0], (rfs - av[0]));
+
+			if ((host = strchr(av[0], '@')) != NULL) {
+				user = strndup( av[0], (host++ - av[0]));
+				host = strndup( host, (rfs++ - host));
+				xav[xac++] = "-l";
+				xav[xac++] = user;
+				xav[xac++] = host;
+			}
+			else {
+				host = strndup( av[0], (rfs++ - av[0]));
+				user = NULL;
+				xav[xac++] = host;
+			}
+
+
 			if (SshPort) {
 				xav[xac++] = "-p";
 				xav[xac++] = SshPort;
 			}
-			xav[xac++] = av[0];
+
 			xav[xac++] = "hammer";
 
 			switch(VerboseOpt) {
@@ -1120,9 +1141,9 @@ again:
 				xav[xac++] = "mirror-read-stream";
 			else
 				xav[xac++] = "mirror-read";
-			xav[xac++] = ptr;
+			xav[xac++] = rfs;
 			xav[xac++] = NULL;
-			execv("/usr/bin/ssh", (void *)xav);
+			execvp(*xav, (void *)xav);
 		} else {
 			hammer_cmd_mirror_read(av, 1, streaming);
 			fflush(stdout);
@@ -1140,17 +1161,37 @@ again:
 		dup2(fds[1], 1);
 		close(fds[0]);
 		close(fds[1]);
-		if ((ptr = strchr(av[1], ':')) != NULL) {
-			*ptr++ = 0;
+		if ((rfs = strchr(av[1], ':')) != NULL) {
 			xac = 0;
-			xav[xac++] = "ssh";
+
+			if((sh = getenv("HAMMER_RSH")) == NULL)
+				xav[xac++] = "ssh";
+			else
+				xav[xac++] = sh;
+
 			if (CompressOpt)
 				xav[xac++] = "-C";
+
+			user = strndup(av[1], (rfs - av[1]));
+
+			if ((host = strchr(av[1], '@')) != NULL) {
+				user = strndup( av[1], (host++ - av[1]));
+				host = strndup( host, (rfs++ - host));
+				xav[xac++] = "-l";
+				xav[xac++] = user;
+				xav[xac++] = host;
+			}
+			else {
+				host = strndup( av[1], (rfs++ - av[1]));
+				user = NULL;
+				xav[xac++] = host;
+			}
+
 			if (SshPort) {
 				xav[xac++] = "-p";
 				xav[xac++] = SshPort;
 			}
-			xav[xac++] = av[1];
+
 			xav[xac++] = "hammer";
 
 			switch(VerboseOpt) {
@@ -1171,9 +1212,9 @@ again:
 			}
 			xav[xac++] = "-2";
 			xav[xac++] = "mirror-write";
-			xav[xac++] = ptr;
+			xav[xac++] = rfs;
 			xav[xac++] = NULL;
-			execv("/usr/bin/ssh", (void *)xav);
+			execvp(*xav, (void *)xav);
 		} else {
 			hammer_cmd_mirror_write(av + 1, 1);
 			fflush(stdout);
diff --git a/sbin/hammer/hammer.8 b/sbin/hammer/hammer.8
index 7c276b9da5..00c884fa8f 100644
--- a/sbin/hammer/hammer.8
+++ b/sbin/hammer/hammer.8
@@ -1360,7 +1360,9 @@ command to a
 command.
 If a remote host specification is made the program forks a
 .Xr ssh 1
-and execs the
+(or other program as specified by the
+.Ev HAMMER_RSH
+environment variable) and execs the
 .Cm mirror-read
 and/or
 .Cm mirror-write
@@ -1800,18 +1802,31 @@ important directories/files can be
 .Nm null
 mounted to the new PFS.
 .Sh ENVIRONMENT
-If the following environment variables exist, they will be used by:
+The following environment variables affect the execution of
+.Nm :
 .Bl -tag -width ".Ev EDITOR"
 .It Ev EDITOR
 The editor program specified in the variable
 .Ev EDITOR
 will be invoked instead of the default editor, which is
 .Xr vi 1 .
+.It Ev HAMMER_RSH
+The command specified in the variable
+.Ev HAMMER_RSH
+will be used to initiate remote operations for the mirror-copy and
+mirror-stream commands instead of the default command, which is
+.Xr ssh 1 .
+The program will be invoked via
+.Xr execvp 3
+using a typical
+.Xr rsh 1
+style
+.Cm -l user host <remote-command>
+command line.
 .It Ev VISUAL
 Same effect as
 .Ev EDITOR
 variable.
-.El
 .Sh FILES
 .Bl -tag -width ".It Pa <fs>/var/slaves/<name>" -compact
 .It Pa <pfs>/snapshots