radius: implemented packet exchange

radius: implemented PAP authorization
radius: implemented IP assigning
triton: implemented userspace context switching
and other stuff

1 files changed, 184 insertions, 18 deletions

diff --git a/accel-pptpd/radius/radius.c b/accel-pptpd/radius/radius.c
index 2e444ded..a786dea5 100644
--- a/accel-pptpd/radius/radius.c
+++ b/accel-pptpd/radius/radius.c
@@ -3,43 +3,124 @@
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
+#include <arpa/inet.h>
 
+#include <openssl/md5.h>
+
+#include "log.h"
 #include "ppp.h"
 #include "pwdb.h"
+#include "ipdb.h"
+
 #include "radius.h"
 
 int conf_max_try = 3;
 int conf_timeout = 3;
 char *conf_nas_identifier = "accel-pptpd";
 char *conf_nas_ip_address;
+char *conf_gw_ip_address;
+int conf_verbose = 0;
+
+char *conf_auth_server;
+int conf_auth_server_port = 1812;
+char *conf_auth_server_secret;
+
+char *conf_acct_server;
+int conf_acct_server_port = 1813;
+char *conf_acct_server_secret;
 
 static struct ppp_notified_t notified;
 
+static struct radius_pd_t *find_pd(struct ppp_t *ppp);
+
+static void proc_attrs(struct rad_req_t *req)
+{
+	struct rad_req_attr_t *attr;
+
+	list_for_each_entry(attr, &req->reply->attrs, entry) {
+		if (!strcmp(attr->attr->name, "Framed-IP-Address")) {
+			req->rpd->ipaddr = attr->val.ipaddr;
+		}
+	}
+}
+
+static uint8_t* encrypt_password(const char *passwd, const char *secret, const uint8_t *RA, int *epasswd_len)
+{
+	uint8_t *epasswd;
+	int i, j, chunk_cnt;
+	uint8_t b[16], c[16];
+	MD5_CTX ctx;
+	
+	chunk_cnt = (strlen(passwd) - 1) / 16 + 1;
+	
+	epasswd = malloc(chunk_cnt * 16);
+	if (!epasswd) {
+		log_error("radius: out of memory\n");
+		return NULL;
+	}
+
+	memset(epasswd, 0, chunk_cnt * 16);
+	memcpy(epasswd, passwd, strlen(passwd));
+	memcpy(c, RA, 16);
+
+	for (i = 0; i < chunk_cnt; i++) {
+		MD5_Init(&ctx);
+		MD5_Update(&ctx, secret, strlen(secret));
+		MD5_Update(&ctx, c, 16);
+		MD5_Final(b, &ctx);
+	
+		for(j = 0; j < 16; j++)
+			epasswd[i * 16 + j] ^= b[j];
+
+		memcpy(c, epasswd + i * 16, 16);
+	}
+
+	*epasswd_len = chunk_cnt * 16;
+	return epasswd;
+}
+
 static int check_pap(struct radius_pd_t *rpd, const char *username, va_list args)
 {
 	struct rad_req_t *req;
 	int i, r = PWDB_DENIED;
 	//int id = va_arg(args, int);
 	const char *passwd = va_arg(args, const char *);
+	uint8_t *epasswd;
+	int epasswd_len;
 
 	req = rad_req_alloc(rpd, CODE_ACCESS_REQUEST, username);
 	if (!req)
 		return PWDB_DENIED;
+	
+	req->server_name = conf_auth_server;
+	req->server_port = conf_auth_server_port;
 
-	if (rad_req_add_str(req, "User-Password", passwd, strlen(passwd)))
+	epasswd = encrypt_password(passwd, conf_auth_server_secret, req->RA, &epasswd_len);
+	if (!epasswd)
 		goto out;
 
+	if (rad_req_add_str(req, "Password", (char*)epasswd, epasswd_len, 0)) {
+		free(epasswd);
+		goto out;
+	}
+
+	free(epasswd);
+
 	for(i = 0; i < conf_max_try; i++) {
 		if (rad_req_send(req))
 			goto out;
 
-		if (rad_req_wait(req, conf_timeout))
-			goto out;
+		rad_req_wait(req, conf_timeout);
 
 		if (req->reply)
 			break;
 	}
 
+	if (req->reply && req->reply->code == CODE_ACCESS_ACCEPT) {
+		proc_attrs(req);
+		r = PWDB_SUCCESS;
+	}
+
 out:
 	rad_req_free(req);
 
@@ -79,15 +160,7 @@ static int check(struct pwdb_t *pwdb, struct ppp_t *ppp, const char *username, i
 	int r = PWDB_NO_IMPL;
 	va_list args;
 	int chap_type;
-	struct ppp_pd_t *pd;
-	struct radius_pd_t *rpd = NULL;
-
-	list_for_each_entry(pd, &ppp->pd_list, entry) {
-		if (pd->key == &notified) {
-			rpd = container_of(pd, typeof(*rpd), pd);
-			break;
-		}
-	}
+	struct radius_pd_t *rpd = find_pd(ppp);
 
 	va_copy(args, _args);
 
@@ -116,6 +189,22 @@ static int check(struct pwdb_t *pwdb, struct ppp_t *ppp, const char *username, i
 	return r;
 }
 
+static int get_ip(struct ppp_t *ppp, in_addr_t *addr, in_addr_t *peer_addr)
+{
+	struct radius_pd_t *rpd = find_pd(ppp);
+	
+	if (rpd->ipaddr) {
+		if (!conf_gw_ip_address) {
+			log_warn("radius: gw-ip-address not specified, cann't assign IP address...\n");
+			return -1;
+		}
+		*peer_addr = rpd->ipaddr;
+		*addr = inet_addr(conf_gw_ip_address);
+		return 0;
+	}
+	return -1;
+}
+
 static void ppp_started(struct ppp_notified_t *n, struct ppp_t *ppp)
 {
 	struct radius_pd_t *pd = malloc(sizeof(*pd));
@@ -128,19 +217,32 @@ static void ppp_started(struct ppp_notified_t *n, struct ppp_t *ppp)
 
 static void ppp_finished(struct ppp_notified_t *n, struct ppp_t *ppp)
 {
+	struct radius_pd_t *rpd = find_pd(ppp);
+
+	list_del(&rpd->pd.entry);
+	free(rpd);
+}
+
+static struct radius_pd_t *find_pd(struct ppp_t *ppp)
+{
 	struct ppp_pd_t *pd;
 	struct radius_pd_t *rpd;
 
 	list_for_each_entry(pd, &ppp->pd_list, entry) {
 		if (pd->key == &notified) {
 			rpd = container_of(pd, typeof(*rpd), pd);
-			list_del(&pd->entry);
-			free(rpd);
-			return;
+			return rpd;
 		}
 	}
+	log_error("radius:BUG: rpd not found\n");
+	abort();
 }
 
+
+static struct ipdb_t ipdb = {
+	.get = get_ip,
+};
+
 static struct pwdb_t pwdb = {
 	.check = check,
 };
@@ -150,17 +252,81 @@ static struct ppp_notified_t notified = {
 	.finished = ppp_finished,
 };
 
+static int parse_server(const char *opt, char **name, int *port, char **secret)
+{
+	char *str = strdup(opt);
+	char *p1, *p2;
+
+	p1 = strstr(str, ":");
+	p2 = strstr(str, ",");
+
+	if (p1)
+		*p1 = 0;
+	if (p2)
+		*p2 = 0;
+	else
+		return -1;
+	
+	*name = str;
+	if (p1) {
+		*port = atoi(p1 + 1);
+		if (*port <=0 )
+			return -1;
+	}
+	*secret = p2 + 1;
+
+	return 0;
+}
+
 static void __init radius_init(void)
 {
-	char *dict = conf_get_opt("radius", "dictionary");
-	if (!dict) {
+	char *opt;
+
+	opt = conf_get_opt("radius", "max-try");
+	if (opt && atoi(opt) > 0)
+		conf_max_try = atoi(opt);
+	
+	opt = conf_get_opt("radius", "timeout");
+	if (opt && atoi(opt) > 0)
+		conf_timeout = atoi(opt);
+
+	opt = conf_get_opt("radius", "verbose");
+	if (opt && atoi(opt) > 0)
+		conf_verbose = 1;
+	
+	opt = conf_get_opt("radius", "nas-ip-address");
+	if (opt)
+		conf_nas_ip_address = opt;
+	
+	opt = conf_get_opt("radius", "gw-ip-address");
+	if (opt)
+		conf_gw_ip_address = opt;
+
+	opt = conf_get_opt("radius", "auth_server");
+	if (!opt) {
+		log_error("radius: auth_server not specified\n");
+		_exit(EXIT_FAILURE);
+	} else if (parse_server(opt, &conf_auth_server, &conf_auth_server_port, &conf_auth_server_secret)) {
+		log_error("radius: failed to parse auth_server\n");
+		_exit(EXIT_FAILURE);
+	}
+
+	opt = conf_get_opt("radius", "acct_server");
+	if (opt && parse_server(opt, &conf_acct_server, &conf_acct_server_port, &conf_acct_server_secret)) {
+		log_error("radius: failed to parse acct_server\n");
+		_exit(EXIT_FAILURE);
+	}
+
+	opt = conf_get_opt("radius", "dictionary");
+	if (!opt) {
 		fprintf(stderr, "radius: dictionary not specified\n");
 		_exit(EXIT_FAILURE);
 	}
-	if (!rad_dict_load(dict))
+	if (rad_dict_load(opt))
 		_exit(EXIT_FAILURE);
 
 	pwdb_register(&pwdb);
+	ipdb_register(&ipdb);
 	ppp_register_notified(&notified);
 }