Mailing List Archive

vpnc's config file processing logic uses EOF to determine when to stop
processing the config input, but if stdin is actually a pipe from a
controlling process, EOF only happens if the pipe is closed. Which
means the controlling process can't respond to any interactive requests
for information. So we need to add some other mechanism to indicate
that config processing is done that does not rely on closing stdin to
indicate this.

Also, getline() only returns on EOF (which has the problems described
above) or when it encounters sufficient newline characters;
unfortunately this precludes using getline() to handle single bytes.
Switch to fgetc() and build up the line ourselves so that we can
recognize a custom EOT character (0x04/Ctl-D) which also terminates
reading configuration without requiring the pipe to be closed.
---
trunk/config.c | 62 +++++++++++++++++++++++++++++++++++++++++++++------
trunk/vpnc.8.template | 10 +++++++++
2 files changed, 65 insertions(+), 7 deletions(-)

v3:
* Recognize CEOT only as the first character of a new line
* Fixed bad whitespace between function name and (

diff --git a/trunk/config.c b/trunk/config.c
index 0351e9b..a6992f7 100644
--- a/trunk/config.c
+++ b/trunk/config.c
@@ -24,14 +24,15 @@
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/utsname.h>
+#include <sys/ttydefaults.h>

#include <gcrypt.h>

#include "sysdep.h"
#include "config.h"
#include "vpnc.h"
#include "supp.h"
@@ -93,14 +94,53 @@ void hex_dump(const char *str, const void *data, ssize_t len, const struct debug
else if (i && !(i % 4))
printf(" ");
printf("%02x", p[i]);
}
printf("\n");
}

+#define GETLINE_MAX_BUFLEN 200
+
+/* mostly match getline() semantics but:
+ * 1) accept CEOT (Ctrl-D, 0x04) at begining of line as an input terminator
+ * 2) always allocate the buffer
+ * 3) max line size of 200 bytes
+ */
+static char *vpnc_getline(size_t *out_size, FILE *stream)
+{
+ char *buf;
+ const size_t buflen = GETLINE_MAX_BUFLEN;
+ size_t llen = 0;
+ int c;
+
+ buf = malloc(buflen);
+ if (buf == NULL)
+ return NULL;
+
+ /* Read a line from the input */
+ while (llen < buflen - 1) {
+ c = fgetc(stream);
+ if (c == EOF || feof(stream)) {
+ if (llen == 0) {
+ free(buf);
+ return NULL;
+ }
+ break;
+ }
+ buf[llen++] = (char) c;
+ /* Break on EOL, or on EOT at the start of a new line */
+ if ((char) c == '\n' || (char) c == '\r' ||
+ ((char) c == CEOT && llen == 1))
+ break;
+ }
+ buf[llen] = '\0';
+ *out_size = llen;
+ return buf;
+}
+
static void config_deobfuscate(int obfuscated, int clear)
{
int ret, len = 0;
char *bin = NULL;

if (config[obfuscated] == NULL)
return;
@@ -481,15 +521,14 @@ static char *get_config_filename(const char *name, int add_dot_conf)
return realname;
}

static void read_config_file(const char *name, const char **configs, int missingok)
{
FILE *f;
char *line = NULL;
- size_t line_length = 0;
int linenum = 0;
char *realname;

if (!strcmp(name, "-")) {
f = stdin;
realname = strdup("stdin");
} else {
@@ -504,22 +543,30 @@ static void read_config_file(const char *name, const char **configs, int missing
free(realname);
return;
}
if (f == NULL)
error(1, errno, "couldn't open `%s'", realname);
}
for (;;) {
- ssize_t llen;
+ size_t llen = 0;
int i;

- llen = getline(&line, &line_length, f);
- if (llen == -1 && feof(f))
+ line = vpnc_getline(&llen, f);
+ if (line == NULL) {
+ if (feof(f))
+ break;
+
+ if (ferror(f))
+ error(1, errno, "reading `%s'", realname);
+ error(1, errno, "out of memory reading `%s'", realname);
+ }
+
+ /* EOT terminates reading configuration in addition to EOF */
+ if (llen == 1 && line[0] == CEOT)
break;
- if (llen == -1)
- error(1, errno, "reading `%s'", realname);
if (llen > 0 && line[llen - 1] == '\n')
line[--llen] = 0;
if (llen > 0 && line[llen - 1] == '\r')
line[--llen] = 0;
linenum++;
for (i = 0; config_names[i].name != NULL; i++) {
if (strncasecmp(config_names[i].name, line,
@@ -556,14 +603,15 @@ static void read_config_file(const char *name, const char **configs, int missing
error(1, errno, "can't allocate memory");
break;
}
}
if (config_names[i].name == NULL && line[0] != '#' && line[0] != 0)
error(0, 0, "warning: unknown configuration directive in %s at line %d",
realname, linenum);
+ free(line);
}
free(line);
free(realname);
if (strcmp(name, "-"))
fclose(f);
}

@@ -820,15 +868,15 @@ void do_config(int argc, char **argv)
case CONFIG_IPSEC_SECRET:
case CONFIG_XAUTH_PASSWORD:
s = strdup(getpass(""));
break;
case CONFIG_IPSEC_GATEWAY:
case CONFIG_IPSEC_ID:
case CONFIG_XAUTH_USERNAME:
- getline(&s, &s_len, stdin);
+ s = vpnc_getline(&s_len, stdin);
}
if (s != NULL && strlen(s) > 0 && s[strlen(s) - 1] == '\n')
s[strlen(s) - 1] = 0;
config[i] = s;
}

if (print_config) {
diff --git a/trunk/vpnc.8.template b/trunk/vpnc.8.template
index 38b3319..c059da9 100644
--- a/trunk/vpnc.8.template
+++ b/trunk/vpnc.8.template
@@ -75,14 +75,24 @@ If no configuration file
is specified on the command-line
at all, both
.B /etc/vpnc/default.conf
and
.B /etc/vpnc.conf
will be loaded.

+.PP
+
+Additionally, if the configuration
+file "-" is specified on the command-line
+vpnc will read configuration from
+stdin. The configuration is parsed and
+the connection proceeds when stdin is
+closed or the special character CEOT
+(CTRL-D) is read.
+
.SH OPTIONS
The program options can be either given as arguments (but not all of them
for security reasons) or be stored in a configuration file.
.PD 0
.\" ###makeman.pl: Insert options from help-output here!

.HP
--
1.8.3.1


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