POTD skeleton #64.

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>

7 files changed, 93 insertions, 14 deletions

diff --git a/src/log.h b/src/log.h
index 345ec64..e5506ed 100644
--- a/src/log.h
+++ b/src/log.h
@@ -30,14 +30,20 @@
 #define ABORT_ON_FATAL(expr, msg) \
     { errno = 0; long rv = (long) expr; \
       if (rv) { \
+          /* \
           E_STRERR("`%s` returned %ld. %s", \
               #expr, rv, msg); abort(); \
+          */ \
+          E_STRERR("%s", msg); abort(); \
       } \
     }
 #define GAI_ABORT_ON_FATAL(expr, msg) \
     { int rv = expr; \
-      if (rv) { E2("`%s` returned: %d", #expr, rv); \
-          E_GAIERR(rv, msg); abort(); } }
+      if (rv) { \
+          /* E2("`%s` returned: %d", #expr, rv); */ \
+          E_GAIERR(rv, msg); abort(); \
+      } \
+    }
 #define C(fmt, ...) log_fmt(CMD, fmt, __VA_ARGS__)
 
 typedef enum log_priority {
diff --git a/src/main.c b/src/main.c
index b2723c0..8130676 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <assert.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 
@@ -15,6 +16,31 @@
 #include "config.h"
 #endif
 
+static void ssh_protocol_preinit(const char *ssh_ports[], protocol_ctx *ctx[],
+                                 const char *jail_ports[], const size_t siz);
+static void ssh_protocol_postinit(protocol_ctx *ctx[], const size_t siz);
+
+
+static void ssh_protocol_preinit(const char *ssh_ports[], protocol_ctx *ctx[],
+                                 const char *jail_ports[], const size_t siz)
+{
+    for (size_t i = 0; i < siz; ++i) {
+        ABORT_ON_FATAL( proto_init_ctx(&ctx[i], ssh_init_cb),
+            "SSH Protocol init" );
+        ABORT_ON_FATAL( proto_setup(ctx[i], "127.0.0.1", ssh_ports[i],
+            "127.0.0.1", jail_ports[i]), "SSH Protocol setup" );
+        ABORT_ON_FATAL( proto_validate_ctx(ctx[i]),
+            "SSH validation" );
+    }
+}
+
+static void ssh_protocol_postinit(protocol_ctx *ctx[], const size_t siz)
+{
+    for (size_t i = 0; i < siz; ++i) {
+        ABORT_ON_FATAL( proto_listen(ctx[i]),
+            "SSH Protocol listen" );
+    }
+}
 
 int main(int argc, char *argv[])
 {
@@ -38,7 +64,9 @@ int main(int argc, char *argv[])
     arg0 = argv[0];
 
     LOG_SET_FUNCS_VA(LOG_COLORED_FUNCS);
+#ifdef HAVE_CONFIG_H
     N("%s (C) 2018 Toni Uhlig (%s)", PACKAGE_STRING, PACKAGE_BUGREPORT);
+#endif
 
     if (geteuid() != 0) {
         E("%s", "I was made for root!");
@@ -60,6 +88,8 @@ int main(int argc, char *argv[])
         FATAL("Forking (fork returned %d)", daemon_pid);
     }
     D2("Master pid: %d", getpid());
+    ABORT_ON_FATAL( set_master_sighandler(),
+        "Master sighandler" );
 
     memset(jail, 0, sizeof(jail));
     jail_ports[0] = "33333";
@@ -85,15 +115,14 @@ int main(int argc, char *argv[])
     memset(ssh_proto, 0, sizeof(proto_ports));
     proto_ports[0] = "22222";
     proto_ports[1] = "22223";
+    assert(SIZEOF(proto_ports) == SIZEOF(jail_ports));
+    ssh_protocol_preinit(proto_ports, ssh_proto, jail_ports, proto_siz);
 
-    for (size_t i = 0; i < proto_siz; ++i) {
-        ABORT_ON_FATAL( proto_init_ctx(&ssh_proto[i], ssh_init_cb),
-            "SSH Protocol init" );
-        ABORT_ON_FATAL( proto_setup(ssh_proto[i], "127.0.0.1", proto_ports[i],
-            "127.0.0.1", jail_ports[i]), "SSH Protocol setup" );
-        ABORT_ON_FATAL( proto_validate_ctx(ssh_proto[i]),
-            "SSH validation" );
-    }
+    D2("Main process is dropping privileges to %s:%s", "nobody", "NULL");
+    ABORT_ON_FATAL( change_user_group("nobody", NULL),
+        "Main process dropping privileges" );
+
+    ssh_protocol_postinit(ssh_proto, proto_siz);
 
     memset(rdr, 0, sizeof(rdr));
     rdr_ports[0] = "2222";
@@ -115,10 +144,6 @@ int main(int argc, char *argv[])
     ABORT_ON_FATAL( redirector_setup_event( rdr, rdr_siz, &rdr_event ),
         "Redirector event setup" );
 
-    D2("Main process is dropping privileges to %s:%s", "nobody", "NULL");
-    ABORT_ON_FATAL( change_user_group("nobody", NULL),
-        "Main process dropping privileges" );
-
     N("%s", "Redirector epoll mainloop");
     rdr_pid = redirector_daemonize( rdr_event, rdr, rdr_siz );
     ABORT_ON_FATAL( rdr_pid < 1, "Server epoll mainloop" );
diff --git a/src/protocol.c b/src/protocol.c
index 5b487f1..ad291de 100644
--- a/src/protocol.c
+++ b/src/protocol.c
@@ -32,6 +32,11 @@ int proto_setup(protocol_ctx *ctx, const char *listen_addr,
     if (fwd_setup_client_silent(&ctx->dst, jail_host, jail_port))
         return 1;
 
+    return 0;
+}
+
+int proto_listen(protocol_ctx *ctx)
+{
     if (!ctx->cbs.on_listen)
         return 1;
     if (ctx->cbs.on_listen(ctx))
diff --git a/src/protocol.h b/src/protocol.h
index 4024aec..cc26d3c 100644
--- a/src/protocol.h
+++ b/src/protocol.h
@@ -30,6 +30,8 @@ int proto_setup(protocol_ctx *ctx, const char *listen_addr,
                 const char *listen_port, const char *jail_host,
                 const char *jail_port);
 
+int proto_listen(protocol_ctx *ctx);
+
 int proto_validate_ctx(const protocol_ctx *ctx);
 
 #endif
diff --git a/src/protocol_ssh.c b/src/protocol_ssh.c
index abed82a..1aaa974 100644
--- a/src/protocol_ssh.c
+++ b/src/protocol_ssh.c
@@ -154,7 +154,15 @@ int ssh_on_shutdown(protocol_ctx *ctx)
 static int set_default_keys(ssh_bind sshbind, int rsa_already_set,
                              int dsa_already_set, int ecdsa_already_set)
 {
+    const char rsa_key[] = "./ssh_host_rsa_key";
+    const char dsa_key[] = "./ssh_host_dsa_key";
+    const char ecdsa_key[] = "./ssh_host_ecdsa_key";
+
     if (!rsa_already_set) {
+        if (access(rsa_key, R_OK)) {
+            E_STRERR("RSA key '%s' inaccessible", rsa_key);
+            return 1;
+        }
         if (ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_RSAKEY,
                                  "./ssh_host_rsa_key")) {
             E2("Faled to set RSA key: %s", ssh_get_error(sshbind));
@@ -162,6 +170,10 @@ static int set_default_keys(ssh_bind sshbind, int rsa_already_set,
         }
     }
     if (!dsa_already_set) {
+        if (access(dsa_key, R_OK)) {
+            E_STRERR("DSA key '%s' inaccesible", dsa_key);
+            return 1;
+        }
         if (ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_DSAKEY,
                                  "./ssh_host_dsa_key")) {
             E2("Failed to set DSA key: %s", ssh_get_error(sshbind));
@@ -169,6 +181,10 @@ static int set_default_keys(ssh_bind sshbind, int rsa_already_set,
         }
     }
     if (!ecdsa_already_set) {
+        if (access(ecdsa_key, R_OK)) {
+            E_STRERR("ECDSA key '%s' inaccesible", ecdsa_key);
+            return 1;
+        }
         if (ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_ECDSAKEY,
                                  "./ssh_host_ecdsa_key")) {
             E2("Failed to set ECDSA key: %s", ssh_get_error(sshbind));
diff --git a/src/utils.c b/src/utils.c
index ca24f6b..455b90d 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -26,6 +26,7 @@ char *arg0 = NULL;
 static int null_fd = -1;
 
 static void sighandler_child(int signo);
+static void sighandler_master(int signo);
 static inline void bin2hex_char(unsigned char c, char hexc[5]);
 
 
@@ -69,6 +70,28 @@ int set_child_sighandler(void)
     return signal(SIGHUP, sighandler_child) == SIG_ERR;
 }
 
+static void sighandler_master(int signo)
+{
+    switch (signo) {
+        case SIGINT:
+        case SIGTERM:
+        case SIGABRT:
+            kill(0, SIGKILL);
+            exit(EXIT_FAILURE);
+    }
+}
+
+int set_master_sighandler(void)
+{
+    int s = 0;
+
+    s |= signal(SIGINT, sighandler_master) == SIG_ERR;
+    s |= signal(SIGTERM, sighandler_master) == SIG_ERR;
+    s |= signal(SIGABRT, sighandler_master) == SIG_ERR;
+
+    return s;
+}
+
 void set_procname(const char *new_arg0)
 {
     assert(arg0);
diff --git a/src/utils.h b/src/utils.h
index 3cd82e7..9ea1024 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -16,6 +16,8 @@ int set_fd_nonblock(int fd);
 
 int set_child_sighandler(void);
 
+int set_master_sighandler(void);
+
 void set_procname(const char *new_arg0);
 
 pid_t daemonize(int stay_foreground);