1 files changed, 226 insertions, 0 deletions
diff --git a/options.c b/options.c
new file mode 100644
index 0000000..ceee3c7
--- /dev/null
+++ b/options.c
@@ -0,0 +1,226 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <string.h>
+#include <getopt.h>
+#include <ctype.h>
+#include <assert.h>
+
+#include "options.h"
+#include "utils.h"
+
+enum option_type {
+	OPT_BOOL, OPT_DEC32, OPT_HEX32, OPT_STR
+};
+
+struct option_usage {
+	const char *short_help;
+	int required;
+	enum option_type otype;
+	union {
+		int32_t num;
+		uint32_t unum;
+		const char *str;
+	};
+	const char *long_help;
+};
+
+static const struct option_usage usage[] = {
+	{"magic",        0, OPT_HEX32,  {.unum = 0xdeadc0de},
+		"Set ptunnel magic hexadecimal number. (32-bit unsigned)\n"
+		"This will be prefixed in all ICMP packets\n"
+		"and can be used to bypass Cisco IPS\n"
+		"This value has to be the same on the server and client!\n"
+	},
+	{"address:port", 1, OPT_STR,    {.unum = 0},
+		"Set address of peer running packet forwarder. This causes\n"
+		"ptunnel to operate in forwarding mode - the absence of this\n"
+		"option causes ptunnel to operate in proxy mode.\n"
+	},
+	{"port",         1, OPT_DEC32,  {.num = 1234},
+		"Set TCP listening port (only used when operating in forward mode)\n"
+	},
+	{"address:port", 1, OPT_STR,    {.str = "127.0.0.1:22"},
+		"Set remote proxy destination address:port if client\n"
+		"Restrict to only this destination address:port if server\n"
+	},
+	{"connections",  0, OPT_DEC32,  {.num = 4},
+		"Set maximum number of concurrent tunnels\n"
+	},
+	{"level",        0, OPT_DEC32,  {.num = 1},
+		"Verbosity level (-1 to 4, where -1 is no output, and 4 is all output)\n"
+	},
+	{NULL,           0, OPT_BOOL,   {.unum = 0},
+		"Enable libpcap on the given device.\n"
+	},
+	{"file",         0, OPT_STR,    {.str = "/var/log/ptunnel.log"},
+		"Specify a file to log to, rather than printing to standard out.\n"
+	},
+	{NULL,           0, OPT_BOOL,   {.unum = 0},
+		"Client only. Enables continuous output of statistics (packet loss, etc.)\n"
+	},
+#ifndef WIN32
+	{NULL,           0, OPT_BOOL,   {.unum = 0},
+		"Run in background, the PID will be written in the file supplied as argument\n"
+	},
+	{NULL,           0, OPT_BOOL,   {.unum = 0},
+		"Output debug to syslog instead of standard out.\n"
+	},
+#endif
+	{NULL,           0, OPT_BOOL,   {.unum = 0},
+		"Toggle use of UDP instead of ICMP. Proxy will listen on port 53 (must be root).\n"
+	},
+	{"password",     0, OPT_STR,    {.str = NULL},
+		"Set password (must be same on client and proxy)\n"
+		"If no password is set, you will be asked during runtime.\n"
+	},
+	{NULL,           0, OPT_BOOL,   {.unum = 0},
+		"Run proxy in unprivileged mode. This causes the proxy to forward\n"
+		"packets using standard echo requests, instead of crafting custom echo replies.\n"
+		"Unprivileged mode will only work on some systems, and is in general less reliable\n"
+		"than running in privileged mode.\n"
+	},
+#ifndef WIN32
+	{"user",         0, OPT_STR,    {.str = "nobody"},
+		"When started in privileged mode, drop down to user's rights as soon as possible\n"
+	},
+	{"group",        0, OPT_STR,    {.str = "nogroup"},
+		"When started in privileged mode, drop down to group's rights as soon as possible\n"
+	},
+	{"directory",    0, OPT_STR,    {.str = "/var/lib/ptunnel"},
+		"When started in privileged mode, restrict file access to the specified directory\n"
+	},
+	{NULL,           0, OPT_BOOL,   {.unum = 0},
+		"Set SELinux context when all there is left to do are network I/O operations\n"
+		"To combine with -chroot you will have to `mount --bind /proc /chrootdir/proc`\n"
+	},
+#endif
+	{NULL,0,OPT_BOOL,{.unum=0},NULL}
+};
+
+static struct option long_options[] = {
+	{"magic",       required_argument, 0, 'm'},
+	{"proxy",       required_argument, 0, 'p'},
+	{"listen",      required_argument, 0, 'l'},
+	{"remote",      required_argument, 0, 'r'},
+	{"connections", required_argument, 0, 'c'},
+	{"verbosity",   required_argument, 0, 'v'},
+	{"libpcap",           no_argument, 0,  0 },
+	{"logfile",     required_argument, 0, 'o'},
+	{"statistics",        no_argument, 0, 's'},
+#ifndef WIN32
+	{"daemon",            no_argument, 0, 'd'},
+	{"syslog",            no_argument, 0,  0 },
+#endif
+	{"udp",               no_argument, 0,  0 },
+	{"passwd",      optional_argument, 0, 'x'},
+	{"unprivileged",      no_argument, 0,  0 },
+	{"user",        required_argument, 0, 'u'},
+	{"group",       required_argument, 0, 'g'},
+	{"chroot",      optional_argument, 0,  0 },
+	{"setcon",            no_argument, 0, 'e'},
+	{NULL,0,0,0}
+};
+
+static void print_multiline(const char *prefix, const char *multiline) {
+	const char sep[] = "\n";
+	const char *start, *end;
+
+	start = multiline;
+	do {
+		if (start) {
+			end = strstr(start, sep);
+			if (end) {
+				printf("%s%.*s\n", prefix, (int)(end-start), start);
+				start = end + strlen(sep);
+			}
+		}
+	} while (start && end);
+}
+
+static void print_long_help(unsigned index, int required_state) {
+	const char spaces[] = "            ";
+
+	if (usage[index].required != required_state)
+		return;
+	if (!long_options[index].name)
+		return;
+
+	if (isalpha(long_options[index].val)) {
+		printf("%.*s-%c --%s\n", 4, spaces, long_options[index].val, long_options[index].name);
+	} else {
+		printf("%.*s--%s\n", 4, spaces, long_options[index].name);
+	}
+
+	if (usage[index].long_help) {
+		print_multiline(&spaces[4], usage[index].long_help);
+	}
+
+	switch (usage[index].otype) {
+		case OPT_BOOL:
+			break;
+		case OPT_DEC32:
+			printf("%s(default: %d)\n", spaces, usage[index].num);
+			break;
+		case OPT_HEX32:
+			printf("%s(default: 0x%X)\n", spaces, usage[index].unum);
+			break;
+		case OPT_STR:
+			if (usage[index].str)
+				printf("%s(default: %s)\n", spaces, usage[index].str);
+			break;
+	}
+}
+
+static void print_short_help(unsigned index, int required_state) {
+	const char *ob = (required_state == 0 ? "[" : "");
+	const char *cb = (required_state == 0 ? "]" : "");
+
+	if (usage[index].required != required_state)
+		return;
+	if (!long_options[index].name)
+		return;
+
+	if (!usage[index].short_help && isalpha(long_options[index].val)) {
+		printf(" %s-%c%s", ob, long_options[index].val, cb);
+	}
+	else if (!usage[index].short_help) {
+		printf(" %s--%s%s", ob, long_options[index].name, cb);
+	}
+	else if (isalpha(long_options[index].val)) {
+		printf(" %s-%c <%s>%s", ob, long_options[index].val, usage[index].short_help, cb);
+	}
+	else {
+		printf(" %s--%s <%s>%s", ob, long_options[index].name, usage[index].short_help, cb);
+	}
+}
+
+void print_usage(const char *arg0) {
+	unsigned i;
+
+	assert( ARRAY_SIZE(long_options) == ARRAY_SIZE(usage) );
+
+	printf("ptunnel-ng v%d.%.2d.\n\nUsage: %s", 12, 22, arg0);
+	/* print (short)help argument line */
+	for (i = 0; i < ARRAY_SIZE(usage); ++i) {
+		print_short_help(i, 1);
+	}
+	for (i = 0; i < ARRAY_SIZE(usage); ++i) {
+		print_short_help(i, 0);
+	}
+
+	printf("%s", "\n\n");
+	/* print (long)help lines */
+	for (i = 0; i < ARRAY_SIZE(usage); ++i) {
+		print_long_help(i, 1);
+	}
+	for (i = 0; i < ARRAY_SIZE(usage); ++i) {
+		print_long_help(i, 0);
+	}
+
+_exit(0);
+}
+
+int parse_options(int argc, char **argv) {
+	return 0;
+}