Move boot to discover server

This change moves the boot-via-kexec functionality from the UIs to the
discover server.

On the UI side: rather than run kexec directly, we just send a message
to the discover server. Because this is generic discover client
functionality, we no longer need the boot callbacks in the twin- and
ncurses-specific code.

We also remove the kexec and URL-loading code from the UIs, and add it
to the discover server code, in paths.c. We expose this to the server
though a new function:

  load_path(void *, const char *, unsigned int *);

On the server side, we simply move hook up the boot() function to use
the load_file and kexec calls.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 277 insertions, 0 deletions

diff --git a/discover/paths.c b/discover/paths.c
index c403691..ef8a45f 100644
--- a/discover/paths.c
+++ b/discover/paths.c
@@ -5,6 +5,9 @@
 #include <stdlib.h>
 
 #include <talloc/talloc.h>
+#include <system/system.h>
+#include <url/url.h>
+#include <log/log.h>
 
 #include "paths.h"
 
@@ -153,3 +156,277 @@ char *join_paths(void *alloc_ctx, const char *a, const char *b)
 	return full_path;
 }
 
+
+static char *local_name(void *ctx)
+{
+	char *tmp, *ret;
+
+	tmp = tempnam(NULL, "pb-");
+
+	if (!tmp)
+		return NULL;
+
+	ret = talloc_strdup(ctx, tmp);
+	free(tmp);
+
+	return ret;
+}
+
+/**
+ * pb_load_nfs - Mounts the NFS export and returns the local file path.
+ *
+ * Returns the local file path in a talloc'ed character string on success,
+ * or NULL on error.
+ */
+static char *load_nfs(void *ctx, struct pb_url *url)
+{
+	int result;
+	const char *argv[8];
+	const char **p;
+	char *local;
+	char *opts;
+
+	local = local_name(ctx);
+
+	if (!local)
+		return NULL;
+
+	result = pb_mkdir_recursive(local);
+
+	if (result)
+		goto fail;
+
+	opts = talloc_strdup(NULL, "ro,nolock,nodiratime");
+
+	if (url->port)
+		opts = talloc_asprintf_append(opts, ",port=%s", url->port);
+
+	p = argv;
+	*p++ = pb_system_apps.mount;	/* 1 */
+	*p++ = "-t";			/* 2 */
+	*p++ = "nfs";			/* 3 */
+	*p++ = opts;			/* 4 */
+	*p++ = url->host;		/* 5 */
+	*p++ = url->dir;		/* 6 */
+	*p++ = local;			/* 7 */
+	*p++ = NULL;			/* 8 */
+
+	result = pb_run_cmd(argv, 1, 0);
+
+	talloc_free(opts);
+
+	if (result)
+		goto fail;
+
+	local = talloc_asprintf_append(local,  "/%s", url->path);
+	pb_log("%s: local '%s'\n", __func__, local);
+
+	return local;
+
+fail:
+	pb_rmdir_recursive("/", local);
+	talloc_free(local);
+	return NULL;
+}
+
+/**
+ * pb_load_sftp - Loads a remote file via sftp and returns the local file path.
+ *
+ * Returns the local file path in a talloc'ed character string on success,
+ * or NULL on error.
+ */
+static char *load_sftp(void *ctx, struct pb_url *url)
+{
+	int result;
+	const char *argv[4];
+	const char **p;
+	char *local;
+
+	local = local_name(ctx);
+
+	if (!local)
+		return NULL;
+
+	p = argv;
+	*p++ = pb_system_apps.sftp;					/* 1 */
+	*p++ = talloc_asprintf(local, "%s:%s", url->host, url->path);	/* 2 */
+	*p++ = local;							/* 3 */
+	*p++ = NULL;							/* 4 */
+
+	result = pb_run_cmd(argv, 1, 0);
+
+	if (result)
+		goto fail;
+
+	return local;
+
+fail:
+	talloc_free(local);
+	return NULL;
+}
+
+/**
+ * pb_load_tftp - Loads a remote file via tftp and returns the local file path.
+ *
+ * Returns the local file path in a talloc'ed character string on success,
+ * or NULL on error.
+ */
+
+static char *load_tftp(void *ctx, struct pb_url *url)
+{
+	int result;
+	const char *argv[10];
+	const char **p;
+	char *local;
+
+	local = local_name(ctx);
+
+	if (!local)
+		return NULL;
+
+	/* first try busybox tftp args */
+
+	p = argv;
+	*p++ = pb_system_apps.tftp;	/* 1 */
+	*p++ = "-g";			/* 2 */
+	*p++ = "-l";			/* 3 */
+	*p++ = local;			/* 4 */
+	*p++ = "-r";			/* 5 */
+	*p++ = url->path;		/* 6 */
+	*p++ = url->host;		/* 7 */
+	if (url->port)
+		*p++ = url->port;	/* 8 */
+	*p++ = NULL;			/* 9 */
+
+	result = pb_run_cmd(argv, 1, 0);
+
+	if (!result)
+		return local;
+
+	/* next try tftp-hpa args */
+
+	p = argv;
+	*p++ = pb_system_apps.tftp;	/* 1 */
+	*p++ = "-m";			/* 2 */
+	*p++ = "binary";		/* 3 */
+	*p++ = url->host;		/* 4 */
+	if (url->port)
+		*p++ = url->port;	/* 5 */
+	*p++ = "-c";			/* 6 */
+	*p++ = "get";			/* 7 */
+	*p++ = url->path;		/* 8 */
+	*p++ = local;			/* 9 */
+	*p++ = NULL;			/* 10 */
+
+	result = pb_run_cmd(argv, 1, 0);
+
+	if (!result)
+		return local;
+
+	talloc_free(local);
+	return NULL;
+}
+
+enum wget_flags {
+	wget_empty = 0,
+	wget_no_check_certificate = 1,
+};
+
+/**
+ * pb_load_wget - Loads a remote file via wget and returns the local file path.
+ *
+ * Returns the local file path in a talloc'ed character string on success,
+ * or NULL on error.
+ */
+
+static char *load_wget(void *ctx, struct pb_url *url, enum wget_flags flags)
+{
+	int result;
+	const char *argv[7];
+	const char **p;
+	char *local;
+
+	local = local_name(ctx);
+
+	if (!local)
+		return NULL;
+
+	p = argv;
+	*p++ = pb_system_apps.wget;			/* 1 */
+#if !defined(DEBUG)
+	*p++ = "--quiet";				/* 2 */
+#endif
+	*p++ = "-O";					/* 3 */
+	*p++ = local;					/* 4 */
+	*p++ = url->full;				/* 5 */
+	if (flags & wget_no_check_certificate)
+		*p++ = "--no-check-certificate";	/* 6 */
+	*p++ = NULL;					/* 7 */
+
+	result = pb_run_cmd(argv, 1, 0);
+
+	if (result)
+		goto fail;
+
+	return local;
+
+fail:
+	talloc_free(local);
+	return NULL;
+}
+
+/**
+ * pb_load_file - Loads a (possibly) remote file and returns the local file
+ * path.
+ * @ctx: The talloc context to associate with the returned string.
+ * @remote: The remote file URL.
+ * @tempfile: An optional variable pointer to be set when a temporary local
+ *  file is created.
+ *
+ * Returns the local file path in a talloc'ed character string on success,
+ * or NULL on error.
+ */
+
+char *load_file(void *ctx, const char *remote, unsigned int *tempfile)
+{
+	struct pb_url *url = pb_url_parse(ctx, remote);
+	char *local;
+	int tmp = 0;
+
+	if (!url)
+		return NULL;
+
+	switch (url->scheme) {
+	case pb_url_ftp:
+	case pb_url_http:
+		local = load_wget(ctx, url, 0);
+		tmp = !!local;
+		break;
+	case pb_url_https:
+		local = load_wget(ctx, url, wget_no_check_certificate);
+		tmp = !!local;
+		break;
+	case pb_url_nfs:
+		local = load_nfs(ctx, url);
+		tmp = !!local;
+		break;
+	case pb_url_sftp:
+		local = load_sftp(ctx, url);
+		tmp = !!local;
+		break;
+	case pb_url_tftp:
+		local = load_tftp(ctx, url);
+		tmp = !!local;
+		break;
+	default:
+		local = talloc_strdup(ctx, url->full);
+		tmp = 0;
+		break;
+	}
+
+	if (tempfile)
+		*tempfile = tmp;
+
+	talloc_free(url);
+	return local;
+}