[Libguestfs] [PATCH 2/4] p2v: Use the ADD_ARG macro to simplify ssh/scp parameters.
Richard W.M. Jones
rjones at redhat.com
Sat Feb 4 14:59:07 UTC 2017
No functional change.
---
p2v/ssh.c | 134 +++++++++++++++++++++++++++++---------------------------------
1 file changed, 62 insertions(+), 72 deletions(-)
diff --git a/p2v/ssh.c b/p2v/ssh.c
index 4c1d64c..817048c 100644
--- a/p2v/ssh.c
+++ b/p2v/ssh.c
@@ -306,6 +306,15 @@ cache_ssh_identity (struct config *config)
return 0;
}
+/* GCC complains about the argv array in the next function which it
+ * thinks might grow to an unbounded size. Since we control
+ * extra_args, this is not in fact a problem.
+ */
+#if defined(__GNUC__) && GUESTFS_GCC_VERSION >= 40800 /* gcc >= 4.8.0 */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstack-usage="
+#endif
+
/**
* Start ssh subprocess with the standard arguments and possibly some
* optional arguments. Also handles authentication.
@@ -314,15 +323,18 @@ static mexp_h *
start_ssh (unsigned spawn_flags, struct config *config,
char **extra_args, int wait_prompt)
{
- size_t i, j, nr_args, count;
+ size_t i = 0;
+ const size_t MAX_ARGS =
+ 64 + (extra_args != NULL ? guestfs_int_count_strings (extra_args) : 0);
+ const char *argv[MAX_ARGS];
char port_str[64];
char connect_timeout_str[128];
- CLEANUP_FREE /* [sic] */ const char **args = NULL;
mexp_h *h;
const int ovecsize = 12;
int ovector[ovecsize];
int saved_timeout;
int using_password_auth;
+ size_t count;
if (cache_ssh_identity (config) == -1)
return NULL;
@@ -330,63 +342,48 @@ start_ssh (unsigned spawn_flags, struct config *config,
/* Are we using password or identity authentication? */
using_password_auth = config->identity_file == NULL;
- /* Create the ssh argument array. */
- nr_args = 0;
- if (extra_args != NULL)
- nr_args = guestfs_int_count_strings (extra_args);
-
- if (using_password_auth)
- nr_args += 13;
- else
- nr_args += 15;
- args = malloc (sizeof (char *) * nr_args);
- if (args == NULL)
- error (EXIT_FAILURE, errno, "malloc");
-
- j = 0;
- args[j++] = "ssh";
- args[j++] = "-p"; /* Port. */
+ ADD_ARG (argv, i, "ssh");
+ ADD_ARG (argv, i, "-p"); /* Port. */
snprintf (port_str, sizeof port_str, "%d", config->port);
- args[j++] = port_str;
- args[j++] = "-l"; /* Username. */
- args[j++] = config->username ? config->username : "root";
- args[j++] = "-o"; /* Host key will always be novel. */
- args[j++] = "StrictHostKeyChecking=no";
- args[j++] = "-o"; /* ConnectTimeout */
+ ADD_ARG (argv, i, port_str);
+ ADD_ARG (argv, i, "-l"); /* Username. */
+ ADD_ARG (argv, i, config->username ? config->username : "root");
+ ADD_ARG (argv, i, "-o"); /* Host key will always be novel. */
+ ADD_ARG (argv, i, "StrictHostKeyChecking=no");
+ ADD_ARG (argv, i, "-o"); /* ConnectTimeout */
snprintf (connect_timeout_str, sizeof connect_timeout_str,
"ConnectTimeout=%d", SSH_TIMEOUT);
- args[j++] = connect_timeout_str;
+ ADD_ARG (argv, i, connect_timeout_str);
if (using_password_auth) {
/* Only use password authentication. */
- args[j++] = "-o";
- args[j++] = "PreferredAuthentications=keyboard-interactive,password";
+ ADD_ARG (argv, i, "-o");
+ ADD_ARG (argv, i, "PreferredAuthentications=keyboard-interactive,password");
}
else {
/* Use identity file (private key). */
- args[j++] = "-o";
- args[j++] = "PreferredAuthentications=publickey";
- args[j++] = "-i";
- args[j++] = config->identity_file;
+ ADD_ARG (argv, i, "-o");
+ ADD_ARG (argv, i, "PreferredAuthentications=publickey");
+ ADD_ARG (argv, i, "-i");
+ ADD_ARG (argv, i, config->identity_file);
}
if (extra_args != NULL) {
- for (i = 0; extra_args[i] != NULL; ++i)
- args[j++] = extra_args[i];
+ for (size_t j = 0; extra_args[j] != NULL; ++j)
+ ADD_ARG (argv, i, extra_args[j]);
}
- args[j++] = config->server; /* Conversion server. */
- args[j++] = NULL;
- assert (j == nr_args);
+ ADD_ARG (argv, i, config->server); /* Conversion server. */
+ ADD_ARG (argv, i, NULL);
#if DEBUG_STDERR
fputs ("ssh command: ", stderr);
- for (i = 0; i < nr_args - 1; ++i) {
+ for (i = 0; argv[i] != NULL; ++i) {
if (i > 0) fputc (' ', stderr);
- fputs (args[i], stderr);
+ fputs (argv[i], stderr);
}
fputc ('\n', stderr);
#endif
/* Create the miniexpect handle. */
- h = mexp_spawnvf (spawn_flags, "ssh", (char **) args);
+ h = mexp_spawnvf (spawn_flags, "ssh", (char **) argv);
if (h == NULL) {
set_ssh_internal_error ("ssh: mexp_spawnvf: %m");
return NULL;
@@ -566,6 +563,10 @@ start_ssh (unsigned spawn_flags, struct config *config,
return h;
}
+#if defined(__GNUC__) && GUESTFS_GCC_VERSION >= 40800 /* gcc >= 4.8.0 */
+#pragma GCC diagnostic pop
+#endif
+
/**
* Upload a file to remote using L<scp(1)>.
*
@@ -574,16 +575,16 @@ start_ssh (unsigned spawn_flags, struct config *config,
int
scp_file (struct config *config, const char *localfile, const char *remotefile)
{
- size_t j, nr_args;
+ size_t i = 0;
+ const size_t MAX_ARGS = 64;
+ const char *argv[MAX_ARGS];
char port_str[64];
char connect_timeout_str[128];
CLEANUP_FREE char *remote = NULL;
- CLEANUP_FREE /* [sic] */ const char **args = NULL;
mexp_h *h;
const int ovecsize = 12;
int ovector[ovecsize];
int using_password_auth;
- size_t i;
if (cache_ssh_identity (config) == -1)
return -1;
@@ -591,58 +592,47 @@ scp_file (struct config *config, const char *localfile, const char *remotefile)
/* Are we using password or identity authentication? */
using_password_auth = config->identity_file == NULL;
- /* Create the scp argument array. */
- if (using_password_auth)
- nr_args = 12;
- else
- nr_args = 14;
- args = malloc (sizeof (char *) * nr_args);
- if (args == NULL)
- error (EXIT_FAILURE, errno, "malloc");
-
- j = 0;
- args[j++] = "scp";
- args[j++] = "-P"; /* Port. */
+ ADD_ARG (argv, i, "scp");
+ ADD_ARG (argv, i, "-P"); /* Port. */
snprintf (port_str, sizeof port_str, "%d", config->port);
- args[j++] = port_str;
- args[j++] = "-o"; /* Host key will always be novel. */
- args[j++] = "StrictHostKeyChecking=no";
- args[j++] = "-o"; /* ConnectTimeout */
+ ADD_ARG (argv, i, port_str);
+ ADD_ARG (argv, i, "-o"); /* Host key will always be novel. */
+ ADD_ARG (argv, i, "StrictHostKeyChecking=no");
+ ADD_ARG (argv, i, "-o"); /* ConnectTimeout */
snprintf (connect_timeout_str, sizeof connect_timeout_str,
"ConnectTimeout=%d", SSH_TIMEOUT);
- args[j++] = connect_timeout_str;
+ ADD_ARG (argv, i, connect_timeout_str);
if (using_password_auth) {
/* Only use password authentication. */
- args[j++] = "-o";
- args[j++] = "PreferredAuthentications=keyboard-interactive,password";
+ ADD_ARG (argv, i, "-o");
+ ADD_ARG (argv, i, "PreferredAuthentications=keyboard-interactive,password");
}
else {
/* Use identity file (private key). */
- args[j++] = "-o";
- args[j++] = "PreferredAuthentications=publickey";
- args[j++] = "-i";
- args[j++] = config->identity_file;
+ ADD_ARG (argv, i, "-o");
+ ADD_ARG (argv, i, "PreferredAuthentications=publickey");
+ ADD_ARG (argv, i, "-i");
+ ADD_ARG (argv, i, config->identity_file);
}
- args[j++] = localfile;
+ ADD_ARG (argv, i, localfile);
if (asprintf (&remote, "%s@%s:%s",
config->username ? config->username : "root",
config->server, remotefile) == -1)
error (EXIT_FAILURE, errno, "asprintf");
- args[j++] = remote;
- args[j++] = NULL;
- assert (j == nr_args);
+ ADD_ARG (argv, i, remote);
+ ADD_ARG (argv, i, NULL);
#if DEBUG_STDERR
fputs ("scp command: ", stderr);
- for (i = 0; i < nr_args - 1; ++i) {
+ for (i = 0; argv[i] != NULL; ++i) {
if (i > 0) fputc (' ', stderr);
- fputs (args[i], stderr);
+ fputs (argv[i], stderr);
}
fputc ('\n', stderr);
#endif
/* Create the miniexpect handle. */
- h = mexp_spawnv ("scp", (char **) args);
+ h = mexp_spawnv ("scp", (char **) argv);
if (h == NULL) {
set_ssh_internal_error ("scp: mexp_spawnv: %m");
return -1;
--
2.10.2
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