Code cleanup

.travis.yml

@@ -30,3 +30,6 @@ deploy:
         tags: true
         repo: angt/glorytun
         condition: "${TRAVIS_OS_NAME}-${CC} == linux-gcc"
+
+after_deploy:
+    - md5sum glorytun-*.tar.gz

Makefile.am

@@ -13,7 +13,9 @@ glorytun_SOURCES = \
     src/option.c \
     src/option.h \
     src/tun.c \
-    src/tun.h
+    src/tun.h \
+    src/db.c \
+    src/db.h
 
 EXTRA_DIST = \
 	LICENSE \

README.md

@@ -1,8 +1,12 @@
 # Glorytun
 
-Small, Simple and Stupid **TCP** VPN.
+Small, Simple and Stupid TCP VPN.
 
-**Work In Progress:** Do not touch! This code will probably format your harddisk!
+#### Work In Progress
+
+This code will probably format your harddisk!
+
+#### Build and Install
 
 Glorytun depends on [libsodium](https://github.com/jedisct1/libsodium) version >= 1.0.4
 and needs an AES-NI capable CPU.
@@ -16,7 +20,4 @@ To build and install the latest version:
     $ make
     # make install
 
-To create and use a new secret key:
-
-    $ hexdump -n 32 /dev/urandom -e '"%X"' > glorytun.key
-    # glorytun keyfile glorytun.key [...]
+For feature requests and bug reports, please create an [issue](https://github.com/angt/glorytun/issues).

src/common-static.h

@@ -18,7 +18,7 @@ static inline void byte_set (void *dst, const char value, size_t size)
 
 static inline void byte_cpy (void *dst, const void *src, size_t size)
 {
-    if (!dst || !src)
+    if (!dst)
         return;
 
     char *restrict d = dst;
@@ -44,16 +44,24 @@ static inline size_t str_cpy (char *restrict dst, const char *restrict src, size
 }
 
 _pure_
-static inline int str_cmp (const char *restrict sa, const char *restrict sb)
+static inline int str_empty (const char *restrict str)
+{
+    return !str || !str[0];
+}
+
+_pure_
+static inline size_t str_cmp (const char *restrict sa, const char *restrict sb)
 {
     if (!sa || !sb)
         return 1;
 
-     while (*sa==*sb++)
-         if (!*sa++)
-             return 0;
+    size_t i = 0;
 
-    return 1;
+    while (sa[i]==sb[i])
+        if (!sa[i++])
+            return 0;
+
+    return i+1;
 }
 
 _pure_

src/common.c

@@ -36,22 +36,25 @@ void gt_fatal (const char *fmt, ...)
 
 void gt_na (const char *name)
 {
-    gt_log("%s is not available on your platform!\n", name);
+    gt_log("%s is not available on your platform\n", name);
 }
 
 int gt_tohex (char *dst, size_t dst_size, const uint8_t *src, size_t src_size)
 {
-    if _0_(dst_size<2*src_size+1)
+    if _0_(!dst_size)
         return -1;
 
-    const char tbl[] = "0123456789ABCDEF";
+    if _0_(((dst_size-1)/2)<src_size)
+        return -1;
+
+    static const char tbl[] = "0123456789ABCDEF";
 
     for (size_t i=0; i<src_size; i++) {
-        dst[(i<<1)+0] = tbl[0xF&(src[i]>>4)];
-        dst[(i<<1)+1] = tbl[0xF&(src[i])];
+        *dst++ = tbl[0xF&(src[i]>>4)];
+        *dst++ = tbl[0xF&(src[i])];
     }
 
-    dst[2*src_size] = 0;
+    *dst = 0;
 
     return 0;
 }
@@ -63,6 +66,9 @@ static inline int fromhex (const char c)
         return c-'0';
 
     if (c>='A' && c<='F')
+        return c-'A'+10;
+
+    if (c>='a' && c<='f')
         return c-'a'+10;
 
     return -1;
@@ -73,7 +79,7 @@ int gt_fromhex (uint8_t *dst, size_t dst_size, const char *src, size_t src_size)
     if _0_(src_size&1)
         return -1;
 
-    if _0_(src_size>2*dst_size)
+    if _0_(dst_size<(src_size/2))
         return -1;
 
     for (size_t i=0; i<src_size; i+=2) {
@@ -83,7 +89,7 @@ int gt_fromhex (uint8_t *dst, size_t dst_size, const char *src, size_t src_size)
         if _0_(a==-1 || b==-1)
             return -1;
 
-        dst[i>>1] = (a<<4)|b;
+        *dst++ = (a<<4)|b;
     }
 
     return 0;

src/common.h

@@ -17,12 +17,14 @@
 #define _1_(x)         (__builtin_expect((x), 1))
 #define _0_(x)         (__builtin_expect((x), 0))
 
-#define _printf_(A,B)  __attribute__((format(printf,A,B)))
-#define _noreturn_     __attribute__((noreturn))
-#define _unused_       __attribute__((unused))
-#define _pure_         __attribute__((pure))
-#define _const_        __attribute__((const))
-#define _align_(...)   __attribute__((aligned(__VA_ARGS__)))
+#define CLZ(x)         (__builtin_clz(x))
+
+#define _printf_(A,B)  __attribute__ ((format(printf,A,B)))
+#define _noreturn_     __attribute__ ((noreturn))
+#define _unused_       __attribute__ ((unused))
+#define _pure_         __attribute__ ((pure))
+#define _const_        __attribute__ ((const))
+#define _align_(...)   __attribute__ ((aligned(__VA_ARGS__)))
 
 typedef struct buffer buffer_t;
 

src/db.c

@@ -0,0 +1,153 @@
+#include "db.h"
+#include "common-static.h"
+
+#define CBIT(X)      (1&(intptr_t)(X))
+#define CBIT_PTR(X)  (uint8_t *)(1|(intptr_t)(X))
+#define CBIT_NODE(X) (struct node *)(1^(intptr_t)(X))
+
+struct node {
+    uint8_t *child[2];
+    uint32_t point;
+};
+
+_pure_
+static inline size_t db_size (const uint8_t *a)
+{
+    return (a[0]?:str_len((char *)a+1))+1;
+}
+
+_pure_
+static inline size_t db_cmp (const uint8_t *a, const uint8_t *b)
+{
+    const size_t size = a[0];
+
+    if (size!=b[0])
+        return 1;
+
+    if (!size) {
+        size_t i = str_cmp((char *)a+1, (char *)b+1);
+        return i?i+1:0;
+    }
+
+    for (size_t i=1; i<=size; i++) {
+        if (a[i]!=b[i])
+            return i+1;
+    }
+
+    return 0;
+}
+
+_pure_
+static inline int db_dir (const uint32_t point, uint8_t *data, const size_t size)
+{
+    const size_t pos = point>>8;
+
+    if (pos>=size)
+        return 0;
+
+    return ((point|data[pos])&255)==255;
+}
+
+uint8_t *db_search (uint8_t **p, uint8_t *data)
+{
+    if _0_(!*p)
+        return NULL;
+
+    uint8_t *r = *p;
+    const size_t size = db_size(data);
+
+    while (CBIT(r)) {
+        struct node *node = CBIT_NODE(r);
+        r = node->child[db_dir(node->point, data, size)];
+    }
+
+    if (!db_cmp(r, data))
+        return r;
+
+    return NULL;
+}
+
+uint8_t *db_insert (uint8_t **p, uint8_t *data)
+{
+    if _0_(CBIT(data))
+        return NULL;
+
+    if _0_(!*p) {
+        *p = data;
+        return data;
+    }
+
+    uint8_t *r = *p;
+    size_t size = db_size(data);
+
+    while (CBIT(r)) {
+        struct node *node = CBIT_NODE(r);
+        r = node->child[db_dir(node->point, data, size)];
+    }
+
+    const size_t diff = db_cmp(r, data);
+
+    if _0_(!diff)
+        return r;
+
+    const size_t pos = diff-1;
+    const uint8_t mask = ~((1u<<31)>>CLZ(r[pos]^data[pos]));
+    const size_t point = (pos<<8)|mask;
+
+    while (CBIT(*p)) {
+        struct node *node = CBIT_NODE(*p);
+
+        if (node->point>point)
+            break;
+
+        p = node->child+db_dir(node->point, data, size);
+    }
+
+    struct node *node = malloc(sizeof(struct node));
+
+    if _0_(!node)
+        return NULL;
+
+    const int dir = (mask|r[pos])==255;
+
+    node->child[dir] = *p;
+    node->child[1-dir] = data;
+    node->point = point;
+
+    *p = CBIT_PTR(node);
+
+    return data;
+}
+
+uint8_t *db_remove (uint8_t **p, uint8_t *data)
+{
+    if _0_(!*p)
+        return NULL;
+
+    const size_t size = db_size(data);
+
+    uint8_t **p_old = NULL;
+    struct node *node = NULL;
+    int dir = 0;
+
+    while (CBIT(*p)) {
+        p_old = p;
+        node = CBIT_NODE(*p);
+        dir = db_dir(node->point, data, size);
+        p = node->child+dir;
+    }
+
+    if _0_(db_cmp(data, *p))
+        return NULL;
+
+    uint8_t *r = *p;
+
+    if (p_old) {
+        *p_old = node->child[1-dir];
+        free(node);
+    } else {
+        *p = NULL;
+    }
+
+    return r;
+}

src/db.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <stdint.h>
+
+uint8_t *db_search (uint8_t **, uint8_t *);
+uint8_t *db_insert (uint8_t **, uint8_t *);
+uint8_t *db_remove (uint8_t **, uint8_t *);

src/ip-static.h

@@ -12,9 +12,9 @@ static inline int ip_get_version (const uint8_t *data, size_t size)
 }
 
 _pure_
-static inline ssize_t ip_get_size (const uint8_t *data, size_t size)
+static inline ssize_t ip_get_size (const int ip_version, const uint8_t *data, size_t size)
 {
-    switch (ip_get_version(data, size)) {
+    switch (ip_version) {
     case 4:
         return ((data[2]<<8)|data[3]);
     case 6:
@@ -27,9 +27,9 @@ static inline ssize_t ip_get_size (const uint8_t *data, size_t size)
 }
 
 _pure_
-static inline ssize_t ip_get_proto (const uint8_t *data, size_t size)
+static inline ssize_t ip_get_proto (const int ip_version, const uint8_t *data, size_t size)
 {
-    switch (ip_get_version(data, size)) {
+    switch (ip_version) {
     case 4:
         return data[9];
     case 6:
@@ -42,9 +42,9 @@ static inline ssize_t ip_get_proto (const uint8_t *data, size_t size)
 }
 
 _pure_
-static inline ssize_t ip_get_hdr_size (const uint8_t *data, size_t size)
+static inline ssize_t ip_get_hdr_size (const int ip_version, const uint8_t *data, size_t size)
 {
-    switch (ip_get_version(data, size)) {
+    switch (ip_version) {
     case 4:
         return (data[0]&0xF)<<2;
     case 6:

src/main.c

@@ -2,12 +2,26 @@
 #include <limits.h>
 #include <stdio.h>
 #include <signal.h>
+#include <string.h>
 #include <poll.h>
 #include <sys/time.h>
 #include <sys/fcntl.h>
-#include <sys/socket.h>
+#include <sys/stat.h>
+
+#ifndef __FAVOR_BSD
+#define __FAVOR_BSD
+#define GT_FAKE_BSD
+#endif
+
 #include <netinet/in.h>
 #include <netinet/tcp.h>
+#include <netinet/udp.h>
+
+#ifdef GT_FAKE_BSD
+#undef GT_FAKE_BSD
+#undef __FAVOR_BSD
+#endif
+
 #include <arpa/inet.h>
 #include <netdb.h>
 
@@ -29,6 +43,9 @@
 #define GT_TUNR_SIZE    (0x7FFF-16)
 #define GT_TUNW_SIZE    (0x7FFF)
 
+#define GT_STARTED "STARTED\n"
+#define GT_STOPPED "STOPPED\n"
+
 struct fdbuf {
     int fd;
     buffer_t read;
@@ -86,6 +103,7 @@ enum sk_opt {
     sk_keepintvl,
     sk_congestion,
     sk_defer_accept,
+    sk_acceptfilter,
     sk_quickack,
 };
 
@@ -131,6 +149,11 @@ static void sk_set (int fd, enum sk_opt opt, const void *val, socklen_t len)
         [sk_quickack] = { "TCP_QUICKACK",
 #ifdef TCP_QUICKACK
             1, IPPROTO_TCP, TCP_QUICKACK,
+#endif
+        },
+        [sk_acceptfilter] = { "SO_ACCEPTFILTER",
+#ifdef SO_ACCEPTFILTER
+            1, SOL_SOCKET, SO_ACCEPTFILTER,
 #endif
         },
     };
@@ -153,21 +176,23 @@ static int sk_listen (int fd, struct addrinfo *ai)
 {
     sk_set_int(fd, sk_reuseaddr, 1);
 
-    int ret = bind(fd, ai->ai_addr, ai->ai_addrlen);
-
-    if (ret==-1) {
+    if (bind(fd, ai->ai_addr, ai->ai_addrlen)==-1) {
         perror("bind");
         return -1;
     }
 
-    ret = listen(fd, 8);
-
-    if (ret==-1) {
+    if (listen(fd, 8)==-1) {
         perror("listen");
         return -1;
     }
 
+#ifdef __linux__
     sk_set_int(fd, sk_defer_accept, GT_TIMEOUT/1000);
+#else
+    char data[256] = {0};
+    str_cpy(data, "dataready", sizeof(data)-1);
+    sk_set(fd, sk_acceptfilter, &data, sizeof(data));
+#endif
 
     return 0;
 }
@@ -321,7 +346,7 @@ static void gt_set_signal (void)
 
 static ssize_t fd_read (int fd, void *data, size_t size)
 {
-    if (!size)
+    if ((fd==-1) || !size)
         return -1;
 
     ssize_t ret = read(fd, data, size);
@@ -341,7 +366,7 @@ static ssize_t fd_read (int fd, void *data, size_t size)
 
 static ssize_t fd_write (int fd, const void *data, size_t size)
 {
-    if (!size)
+    if ((fd==-1) || !size)
         return -1;
 
     ssize_t ret = write(fd, data, size);
@@ -362,15 +387,10 @@ static ssize_t fd_write (int fd, const void *data, size_t size)
     return ret;
 }
 
-static ssize_t fd_read_all (int fd, void *data, size_t size)
+static size_t fd_read_all (int fd, void *data, size_t size)
 {
     size_t done = 0;
 
-    struct pollfd pollfd = {
-        .fd = fd,
-        .events = POLLIN,
-    };
-
     while (done<size) {
         ssize_t ret = fd_read(fd, (uint8_t *)data+done, size-done);
 
@@ -378,8 +398,14 @@ static ssize_t fd_read_all (int fd, void *data, size_t size)
             break;
 
         if (ret<0) {
+            struct pollfd pollfd = {
+                .fd = fd,
+                .events = POLLIN,
+            };
+
             if (!poll(&pollfd, 1, GT_TIMEOUT))
                 break;
+
             continue;
         }
 
@@ -389,15 +415,10 @@ static ssize_t fd_read_all (int fd, void *data, size_t size)
     return done;
 }
 
-static ssize_t fd_write_all (int fd, const void *data, size_t size)
+static size_t fd_write_all (int fd, const void *data, size_t size)
 {
     size_t done = 0;
 
-    struct pollfd pollfd = {
-        .fd = fd,
-        .events = POLLOUT,
-    };
-
     while (done<size) {
         ssize_t ret = fd_write(fd, (const uint8_t *)data+done, size-done);
 
@@ -405,8 +426,14 @@ static ssize_t fd_write_all (int fd, const void *data, size_t size)
             break;
 
         if (ret<0) {
+            struct pollfd pollfd = {
+                .fd = fd,
+                .events = POLLOUT,
+            };
+
             if (!poll(&pollfd, 1, GT_TIMEOUT))
                 break;
+
             continue;
         }
 
@@ -483,55 +510,79 @@ static int gt_decrypt (struct crypto_ctx *ctx, buffer_t *dst, buffer_t *src)
     return 0;
 }
 
-static void gt_print_hdr (uint8_t *data, size_t ip_size, const char *sockname)
+static void gt_print_hdr (const int ip_version, uint8_t *data, size_t ip_size, const char *sockname)
 {
-    const int ip_version = ip_get_version(data, GT_MTU_MAX);
-    const ssize_t ip_proto = ip_get_proto(data, GT_MTU_MAX);
-    const ssize_t ip_hdr_size = ip_get_hdr_size(data, GT_MTU_MAX);
+    const ssize_t ip_proto = ip_get_proto(ip_version, data, ip_size);
+    const ssize_t ip_hdr_size = ip_get_hdr_size(ip_version, data, ip_size);
 
-    char ip_src[33];
-    char ip_dst[33];
+    char ip_src[INET6_ADDRSTRLEN];
+    char ip_dst[INET6_ADDRSTRLEN];
 
     switch (ip_version) {
-        case 4:
-            gt_tohex(ip_src, sizeof(ip_src), &data[12], 4);
-            gt_tohex(ip_dst, sizeof(ip_dst), &data[16], 4);
-            break;
-        case 6:
-            gt_tohex(ip_src, sizeof(ip_src), &data[9], 16);
-            gt_tohex(ip_dst, sizeof(ip_dst), &data[25], 16);
-            break;
+    case 4:
+        inet_ntop(AF_INET, &data[12], ip_src, sizeof(ip_src));
+        inet_ntop(AF_INET, &data[16], ip_dst, sizeof(ip_dst));
+        break;
+    case 6:
+        inet_ntop(AF_INET6, &data[9],  ip_src, sizeof(ip_src));
+        inet_ntop(AF_INET6, &data[25], ip_dst, sizeof(ip_dst));
+        break;
     }
 
     gt_log("%s: version=%i size=%zi proto=%zi src=%s dst=%s\n", sockname, ip_version, ip_size, ip_proto, ip_src, ip_dst);
 
-    if (ip_hdr_size<=0 || ip_proto!=6)
+    if (ip_hdr_size<=0)
         return;
 
-    struct tcphdr tcp;
+    if (ip_proto==6) {
+        struct tcphdr tcp;
 
-    byte_cpy(&tcp, &data[ip_hdr_size], sizeof(tcp));
+        byte_cpy(&tcp, &data[ip_hdr_size], sizeof(tcp));
 
-    tcp.source = ntohs(tcp.source);
-    tcp.dest = ntohs(tcp.dest);
-    tcp.seq = ntohl(tcp.seq);
-    tcp.ack_seq = ntohl(tcp.ack_seq);
-    tcp.window = ntohs(tcp.window);
+        tcp.th_sport = ntohs(tcp.th_sport);
+        tcp.th_dport = ntohs(tcp.th_dport);
+        tcp.th_seq = ntohl(tcp.th_seq);
+        tcp.th_ack = ntohl(tcp.th_ack);
+        tcp.th_win = ntohs(tcp.th_win);
 
-    gt_log("%s: tcp src=%i dst=%i seq=%u ack=%u win=%u %s%s%s%s%s%s\n",
-            sockname, tcp.source, tcp.dest, tcp.seq, tcp.ack_seq, tcp.window,
-            tcp.fin?"FIN ":"", tcp.syn?"SYN ":"", tcp.rst?"RST ":"",
-            tcp.psh?"PSH ":"", tcp.ack?"ACK ":"", tcp.urg?"URG ":"");
+        gt_log("%s: tcp src=%u dst=%u seq=%u ack=%u win=%u %c%c%c%c%c%c\n",
+                sockname, tcp.th_sport, tcp.th_dport, tcp.th_seq, tcp.th_ack, tcp.th_win,
+                (tcp.th_flags&TH_FIN) ?'F':'.',
+                (tcp.th_flags&TH_SYN) ?'S':'.',
+                (tcp.th_flags&TH_RST) ?'R':'.',
+                (tcp.th_flags&TH_PUSH)?'P':'.',
+                (tcp.th_flags&TH_ACK) ?'A':'.',
+                (tcp.th_flags&TH_URG) ?'U':'.');
+    }
+
+    if (ip_proto==17) {
+        struct udphdr udp;
+
+        byte_cpy(&udp, &data[ip_hdr_size], sizeof(udp));
+
+        udp.uh_sport = ntohs(udp.uh_sport);
+        udp.uh_dport = ntohs(udp.uh_dport);
+        udp.uh_ulen = ntohs(udp.uh_ulen);
+
+        gt_log("%s: udp src=%u dst=%u len=%u\n",
+                sockname, udp.uh_sport, udp.uh_dport, udp.uh_ulen);
+    }
 }
 
 static int gt_setup_secretkey (struct crypto_ctx *ctx, char *keyfile)
 {
     const size_t size = sizeof(ctx->skey);
 
-    byte_set(ctx->skey, 1, size);
+    if (!keyfile) {
+        char buf[2*size+1];
+
+        randombytes_buf(ctx->skey, size);
+        gt_tohex(buf, sizeof(buf), ctx->skey, size);
+
+        gt_print("new secret key: %s\n", buf);
 
-    if (!keyfile)
         return 0;
+    }
 
     int fd;
 
@@ -564,10 +615,11 @@ static int gt_setup_secretkey (struct crypto_ctx *ctx, char *keyfile)
 
 static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
 {
+    const size_t size = 96;
+    const size_t hash_size = 32;
+
     const size_t nonce_size = crypto_aead_aes256gcm_NPUBBYTES;
     const size_t public_size = crypto_scalarmult_SCALARBYTES;
-    const size_t hash_size = crypto_generichash_BYTES;
-    const size_t size = nonce_size + public_size + hash_size;
 
     uint8_t secret[crypto_scalarmult_SCALARBYTES];
     uint8_t shared[crypto_scalarmult_BYTES];
@@ -579,10 +631,14 @@ static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
 
     crypto_generichash_state state;
 
+    byte_set(data_w, 0, size);
     randombytes_buf(data_w, nonce_size);
+
     randombytes_buf(secret, sizeof(secret));
     crypto_scalarmult_base(&data_w[nonce_size], secret);
 
+    byte_cpy(&data_w[size-hash_size-4], "GT\0\0", 4);
+
     crypto_generichash(&data_w[size-hash_size], hash_size,
             data_w, size-hash_size, ctx->skey, sizeof(ctx->skey));
 
@@ -592,6 +648,9 @@ static int gt_setup_crypto (struct crypto_ctx *ctx, int fd, int listener)
     if (fd_read_all(fd, data_r, size)!=size)
         return -1;
 
+    if (memcmp(&data_r[size-hash_size-4], &data_w[size-hash_size-4], 4))
+        return -2;
+
     crypto_generichash(hash, hash_size,
             data_r, size-hash_size, ctx->skey, sizeof(ctx->skey));
 
@@ -649,9 +708,10 @@ int main (int argc, char **argv)
 
     char *host = NULL;
     char *port = "5000";
-    char *dev = PACKAGE_NAME;
+    char *dev = NULL;
     char *keyfile = NULL;
     char *congestion = NULL;
+    char *statefile = NULL;
 
     long buffer_size = GT_BUFFER_SIZE;
 
@@ -693,6 +753,7 @@ int main (int argc, char **argv)
         { "noquickack",  NULL,         option_option },
         { "retry",       &retry_opts,  option_option },
         { "daemon",      NULL,         option_option },
+        { "statefile",   &statefile,   option_str    },
         { "debug",       NULL,         option_option },
         { "version",     NULL,         option_option },
         { NULL },
@@ -714,14 +775,26 @@ int main (int argc, char **argv)
 
     if (buffer_size < 2048) {
         buffer_size = 2048;
-        gt_log("buffer size must be greater than 2048!\n");
+        gt_log("buffer size must be greater than 2048\n");
     }
 
-    if (!listener && !option_is_set(opts, "retry"))
-        retry_count = 0;
+    if (!listener) {
+        if (!option_is_set(opts, "keyfile")) {
+            gt_log("keyfile option must be set\n");
+            return 1;
+        }
+
+        if (!option_is_set(opts, "retry"))
+            retry_count = 0;
+    }
+
+    if (statefile && statefile[0]!='/') {
+        gt_log("statefile must be an absolute path\n");
+        return 1;
+    }
 
     if (sodium_init()==-1) {
-        gt_log("libsodium initialization has failed!\n");
+        gt_log("libsodium initialization has failed\n");
         return 1;
     }
 
@@ -730,11 +803,6 @@ int main (int argc, char **argv)
         return 1;
     }
 
-    struct crypto_ctx ctx;
-
-    if (gt_setup_secretkey(&ctx, keyfile))
-        return 1;
-
     struct addrinfo *ai = ai_create(host, port, listener);
 
     if (!ai)
@@ -745,8 +813,10 @@ int main (int argc, char **argv)
 
     tun.fd = tun_create(dev, option_is_set(opts, "multiqueue"));
 
-    if (tun.fd==-1)
+    if (tun.fd==-1) {
+        gt_log("couldn't create tun device\n");
         return 1;
+    }
 
     struct blk *blks = calloc(256, sizeof(struct blk));
     size_t blk_count = 0;
@@ -773,6 +843,11 @@ int main (int argc, char **argv)
             return 1;
     }
 
+    struct crypto_ctx ctx;
+
+    if (gt_setup_secretkey(&ctx, keyfile))
+        return 1;
+
     if (option_is_set(opts, "daemon")) {
         switch (fork()) {
         case -1:
@@ -789,6 +864,30 @@ int main (int argc, char **argv)
         chdir("/");
     }
 
+    int state_fd = -1;
+
+    if (statefile) {
+        state_fd = open(statefile, O_WRONLY);
+
+        if (state_fd==-1) {
+            if (errno!=EINTR)
+                perror("open statefile");
+            return 1;
+        }
+
+        struct stat st = {0};
+
+        if (fstat(state_fd, &st)==-1) {
+            perror("stat statefile");
+            return 1;
+        }
+
+        if (!S_ISFIFO(st.st_mode)) {
+            gt_log("`%s' is not a fifo\n", statefile);
+            return 1;
+        }
+    }
+
     long retry = 0;
 
     while (!gt_close) {
@@ -856,7 +955,7 @@ int main (int argc, char **argv)
 
         retry = 0;
 
-        gt_log("%s: running\n", sockname);
+        fd_write(state_fd, GT_STARTED, sizeof(GT_STARTED)-1);
 
         fd_set rfds;
         FD_ZERO(&rfds);
@@ -916,7 +1015,8 @@ int main (int argc, char **argv)
                         break;
                     }
 
-                    const ssize_t ip_size = ip_get_size(data, GT_MTU_MAX);
+                    const int ip_version = ip_get_version(data, GT_MTU_MAX);
+                    const ssize_t ip_size = ip_get_size(ip_version, data, GT_MTU_MAX);
 
                     if _0_(ip_size<=0)
                         continue;
@@ -929,8 +1029,7 @@ int main (int argc, char **argv)
                     }
 
                     if _0_(debug)
-                        gt_print_hdr(data, ip_size, sockname);
-
+                        gt_print_hdr(ip_version, data, ip_size, sockname);
 
                     blks[blk_write++].size = r;
                     blk_count++;
@@ -1005,7 +1104,9 @@ int main (int argc, char **argv)
                 }
 
                 size_t size = buffer_read_size(&tun.write);
-                ssize_t ip_size = ip_get_size(tun.write.read, size);
+
+                const int ip_version = ip_get_version(tun.write.read, size);
+                ssize_t ip_size = ip_get_size(ip_version, tun.write.read, size);
 
                 if _0_(!ip_size) {
                     gt_log("%s: bad packet!\n", sockname);
@@ -1027,6 +1128,8 @@ int main (int argc, char **argv)
         }
 
     restart:
+        fd_write(state_fd, GT_STOPPED, sizeof(GT_STOPPED)-1);
+
         if (sockname) {
             free(sockname);
             sockname = NULL;

src/tun.c

@@ -11,116 +11,148 @@
 #include <sys/uio.h>
 
 #ifdef __linux__
-# include <linux/if.h>
-# include <linux/if_tun.h>
+#include <linux/if.h>
+#include <linux/if_tun.h>
 #endif
 
 #ifdef __APPLE__
-# include <sys/sys_domain.h>
-# include <sys/kern_control.h>
-# include <net/if_utun.h>
+#include <sys/sys_domain.h>
+#include <sys/kern_control.h>
+#include <net/if_utun.h>
 #endif
 
 #if defined(__APPLE__) || defined(__OpenBSD__)
-# define GT_BSD_TUN 1
+#define GT_BSD_TUN
 #endif
 
+#ifdef __APPLE__
+
+static int tun_create_by_id (char *name, size_t size, unsigned id, _unused_ int mq)
+{
+    int fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
+
+    if (fd==-1)
+        return -1;
+
+    struct ctl_info ci;
+
+    byte_set(&ci, 0, sizeof(ci));
+    str_cpy(ci.ctl_name, UTUN_CONTROL_NAME, sizeof(ci.ctl_name)-1);
+
+    if (ioctl(fd, CTLIOCGINFO, &ci)) {
+        close(fd);
+        return -1;
+    }
+
+    struct sockaddr_ctl sc = {
+        .sc_id = ci.ctl_id,
+        .sc_len = sizeof(sc),
+        .sc_family = AF_SYSTEM,
+        .ss_sysaddr = AF_SYS_CONTROL,
+        .sc_unit = id+1,
+    };
+
+    if (connect(fd, (struct sockaddr *)&sc, sizeof(sc))) {
+        close(fd);
+        return -1;
+    }
+
+    snprintf(name, size, "utun%u", id);
+
+    return fd;
+}
+
+static int tun_create_by_name (char *name, size_t size, char *dev_name, int mq)
+{
+    unsigned id = 0;
+
+    if (sscanf(dev_name, "utun%u", &id)!=1)
+        return -1;
+
+    return tun_create_by_id(name, size, id, mq);
+}
+
+#else /* not __APPLE__ */
+
 #ifdef __linux__
-int tun_create (char *name, int multiqueue)
+
+static int tun_create_by_name (char *name, size_t size, char *dev_name, int mq)
 {
     int fd = open("/dev/net/tun", O_RDWR);
 
-    if (fd<0) {
-        perror("open /dev/net/tun");
+    if (fd==-1)
         return -1;
-    }
 
     struct ifreq ifr = {
         .ifr_flags = IFF_TUN|IFF_NO_PI,
     };
 
-    if (multiqueue) {
+    if (mq) {
 #ifdef IFF_MULTI_QUEUE
         ifr.ifr_flags |= IFF_MULTI_QUEUE;
-#else
-        gt_na("IFF_MULTI_QUEUE");
 #endif
     }
 
-    str_cpy(ifr.ifr_name, name, IFNAMSIZ-1);
+    str_cpy(ifr.ifr_name, dev_name, IFNAMSIZ-1);
 
-    int ret = ioctl(fd, TUNSETIFF, &ifr);
-
-    if (ret<0) {
-        perror("ioctl TUNSETIFF");
+    if (ioctl(fd, TUNSETIFF, &ifr)) {
+        close(fd);
         return -1;
     }
 
-    gt_log("tun name: %s\n", ifr.ifr_name);
+    str_cpy(name, ifr.ifr_name, size-1);
 
     return fd;
 }
-#elif defined(__APPLE__)
-int tun_create (_unused_ char *name, _unused_ int mq)
+
+#else /* not __linux__ not __APPLE__ */
+
+static int tun_create_by_name (char *name, size_t size, char *dev_name, _unused_ int mq)
 {
-    for (unsigned dev_id = 0; dev_id < 32; dev_id++) {
-        struct ctl_info ci;
+    char path[64];
 
-        byte_set(&ci, 0, sizeof(ci));
-        str_cpy(ci.ctl_name, UTUN_CONTROL_NAME, sizeof(ci.ctl_name)-1);
+    snprintf(path, sizeof(path), "/dev/%s", dev_name);
+    str_cpy(name, dev_name, size-1);
 
-        int fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
-
-        if (fd==-1)
-            return -1;
-
-        if (ioctl(fd, CTLIOCGINFO, &ci)==-1) {
-            close(fd);
-            continue;
-        }
-
-        struct sockaddr_ctl sc = {
-            .sc_id = ci.ctl_id,
-            .sc_len = sizeof(sc),
-            .sc_family = AF_SYSTEM,
-            .ss_sysaddr = AF_SYS_CONTROL,
-            .sc_unit = dev_id+1,
-        };
-
-        if (connect(fd, (struct sockaddr *)&sc, sizeof(sc))==-1) {
-            close(fd);
-            continue;
-        }
-
-        gt_log("tun name: /dev/utun%u\n", dev_id);
-
-        return fd;
-    }
-
-    return -1;
+    return open(path, O_RDWR);
 }
-#else
-int tun_create (_unused_ char *name, _unused_ int mq)
+
+#endif /* not __APPLE__ */
+
+static int tun_create_by_id (char *name, size_t size, unsigned id, int mq)
 {
-    for (unsigned dev_id = 0; dev_id < 32; dev_id++) {
-        char dev_path[11];
+    char dev_name[64];
 
-        snprintf(dev_path, sizeof(dev_path), "/dev/tun%u", dev_id);
+    snprintf(dev_name, sizeof(dev_name), "tun%u", id);
 
-        int fd = open(dev_path, O_RDWR);
-
-        if (fd==-1)
-            continue;
-
-        gt_log("tun name: %s\n", dev_path);
-
-        return fd;
-    }
-
-    return -1;
+    return tun_create_by_name(name, size, dev_name, mq);
 }
+
 #endif
 
+int tun_create (char *dev_name, int mq)
+{
+    char name[64];
+    int fd = -1;
+
+#ifndef IFF_MULTI_QUEUE
+    if (mq)
+        gt_na("IFF_MULTI_QUEUE");
+#endif
+
+    if (str_empty(dev_name)) {
+        for (unsigned id=0; id<32 && fd==-1; id++)
+            fd = tun_create_by_id(name, sizeof(name), id, mq);
+    } else {
+        fd = tun_create_by_name(name, sizeof(name), dev_name, mq);
+    }
+
+    if (fd!=-1)
+        gt_print("tun name: %s\n", name);
+
+    return fd;
+}
+
 ssize_t tun_read (int fd, void *data, size_t size)
 {
     if (!size)