POTD skeleton #61.

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

9 files changed, 136 insertions, 10 deletions

diff --git a/src/jail.c b/src/jail.c
index ad26b8e..021d634 100644
--- a/src/jail.c
+++ b/src/jail.c
@@ -26,8 +26,12 @@ typedef struct server_event {
 } server_event;
 
 typedef struct client_event {
-    const psocket *client_sock;
-    const int tty_fd;
+    psocket *client_sock;
+    int tty_fd;
+    char tty_logbuf[BUFSIZ];
+    size_t off_logbuf;
+    char *tty_logbuf_escaped;
+    size_t tty_logbuf_size;
 } client_event;
 
 static int jail_mainloop(event_ctx **ev_ctx, const jail_ctx *ctx[], size_t siz)
@@ -37,6 +41,8 @@ static int jail_childfn(prisoner_process *ctx)
     __attribute__((noreturn));
 static int jail_socket_tty(prisoner_process *ctx, int tty_fd);
 static int jail_socket_tty_io(event_ctx *ev_ctx, int src_fd, void *user_data);
+static int jail_log_input(event_ctx *ev_ctx, int src_fd, int dst_fd,
+                          char *buf, size_t siz, void *user_data);
 
 
 void jail_init_ctx(jail_ctx **ctx, size_t stacksize)
@@ -251,6 +257,7 @@ static int jail_childfn(prisoner_process *ctx)
         FATAL("Clearing ENV for pid %d", self_pid);
 
     caps_drop_dac_override(0);
+    caps_drop_all();
 
     D2("Unshare prisoner %d", self_pid);
     if (unshare(unshare_flags))
@@ -321,6 +328,7 @@ static int jail_childfn(prisoner_process *ctx)
 */
             if (close_fds_except(0, 1, 2, -1))
                 exit(EXIT_FAILURE);
+
             printf("%s",
                 "  _______                     ________        __\n"
                 " |       |.-----.-----.-----.|  |  |  |.----.|  |_\n"
@@ -339,6 +347,7 @@ static int jail_childfn(prisoner_process *ctx)
                 "  * 1 splash Cranberry juice\n"
                 " -----------------------------------------------------\n"
             );
+
             if (execl(path_shell, path_shell, (char *) NULL))
                 exit(EXIT_FAILURE);
         default:
@@ -359,11 +368,12 @@ static int jail_childfn(prisoner_process *ctx)
 
 static int jail_socket_tty(prisoner_process *ctx, int tty_fd)
 {
-    client_event ev_cli = {NULL, tty_fd};
+    static client_event ev_cli = {NULL, 0, {0}, 0, 0, 0};
     int s, rc = 1;
     event_ctx *ev_ctx = NULL;
 
     assert(ctx);
+    ev_cli.tty_fd = tty_fd;
 
     event_init(&ev_ctx);
     if (event_setup(ev_ctx)) {
@@ -412,7 +422,8 @@ jail_socket_tty_io(event_ctx *ev_ctx, int src_fd, void *user_data)
         dest_fd = ev_cli->client_sock->fd;
     } else return 0;
 
-    fwd_state = event_forward_connection(ev_ctx, dest_fd);
+    fwd_state = event_forward_connection(ev_ctx, dest_fd, jail_log_input,
+                                         user_data);
 
     switch (fwd_state) {
         case CON_IN_TERMINATED:
@@ -428,3 +439,40 @@ jail_socket_tty_io(event_ctx *ev_ctx, int src_fd, void *user_data)
 
     return 1;
 }
+
+static int jail_log_input(event_ctx *ev_ctx, int src_fd, int dst_fd,
+                          char *buf, size_t siz, void *user_data)
+{
+    size_t idx = 0, slen, ssiz = siz;
+    client_event *ev_cli = (client_event *) user_data;
+
+    (void) ev_ctx;
+    (void) src_fd;
+
+    if (ev_cli->tty_fd == dst_fd) {
+        while (ssiz > 0) {
+            slen = MIN(sizeof(ev_cli->tty_logbuf) - ev_cli->off_logbuf, ssiz);
+            if (slen == 0) {
+                escape_ascii_string(ev_cli->tty_logbuf, ev_cli->off_logbuf,
+                                    &ev_cli->tty_logbuf_escaped, &ev_cli->tty_logbuf_size);
+                C("%s", ev_cli->tty_logbuf_escaped);
+                ev_cli->off_logbuf = 0;
+                ev_cli->tty_logbuf[0] = 0;
+                continue;
+            }
+            strncat(ev_cli->tty_logbuf, buf+idx, slen);
+            ssiz -= slen;
+            idx += slen;
+            ev_cli->off_logbuf += slen;
+        }
+        if (buf[siz-1] == '\r' || buf[siz-1] == '\n') {
+            escape_ascii_string(ev_cli->tty_logbuf, ev_cli->off_logbuf,
+                                &ev_cli->tty_logbuf_escaped, &ev_cli->tty_logbuf_size);
+            C("%s", ev_cli->tty_logbuf_escaped);
+            ev_cli->off_logbuf = 0;
+            ev_cli->tty_logbuf[0] = 0;
+        }
+    }
+
+    return 0;
+}
diff --git a/src/log.h b/src/log.h
index 1672097..345ec64 100644
--- a/src/log.h
+++ b/src/log.h
@@ -38,9 +38,10 @@
     { int rv = expr; \
       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 {
-    DEBUG = 0, NOTICE, WARNING, ERROR
+    DEBUG = 0, NOTICE, WARNING, ERROR, CMD
 } log_priority;
 
 typedef int (*log_open_cb) (void);
diff --git a/src/log_colored.c b/src/log_colored.c
index 5434562..71f6d42 100644
--- a/src/log_colored.c
+++ b/src/log_colored.c
@@ -54,6 +54,9 @@ void log_fmt_colored(log_priority prio, const char *fmt, ...)
         case ERROR:
             printf("[" RED "ERROR" RESET "]  [%d] %s\n", my_pid, out);
             break;
+        case CMD:
+            printf("[" BLUE "CMD" RESET "]    [%d] %s\n", my_pid, out);
+            break;
     }
 }
 
@@ -86,6 +89,8 @@ void log_fmtex_colored(log_priority prio, const char *srcfile,
             printf("[" RED "ERROR" RESET "]  [%d] %s.%lu: %s\n",
                 my_pid, srcfile, line, out);
             break;
+        case CMD:
+            break;
     }
 }
 
@@ -143,5 +148,7 @@ void log_fmtexerr_colored(log_priority prio, const char *srcfile,
                     my_pid, srcfile,
                     line, out);
             break;
+        case CMD:
+            break;
     }
 }
diff --git a/src/log_colored.h b/src/log_colored.h
index 9f75557..b06a2f5 100644
--- a/src/log_colored.h
+++ b/src/log_colored.h
@@ -8,6 +8,7 @@
 #define GRN   "\x1B[32;1m"
 #define YEL   "\x1B[33;1m"
 #define RED   "\x1B[31;1;5m"
+#define BLUE  "\x1B[34;1;1m"
 /* LOG_SET_FUNCS comfort */
 #define LOG_COLORED_FUNCS log_open_colored, log_close_colored, \
     log_fmt_colored, log_fmtex_colored, log_fmtexerr_colored
diff --git a/src/pevent.c b/src/pevent.c
index 70fb311..3007472 100644
--- a/src/pevent.c
+++ b/src/pevent.c
@@ -113,14 +113,15 @@ int event_loop(event_ctx *ctx, on_event_cb on_event, void *user_data)
 }
 
 forward_state
-event_forward_connection(event_ctx *ctx, int dest_fd)
+event_forward_connection(event_ctx *ctx, int dest_fd, on_data_cb on_data,
+                         void *user_data)
 {
     int data_avail = 1;
     int has_input;
     int saved_errno;
     forward_state rc = CON_OK;
     ssize_t siz;
-    char buf[BUFSIZ+sizeof(long)];
+    char buf[BUFSIZ];
     struct epoll_event *ev;
 
     assert(ctx->current_event >= 0 &&
@@ -151,7 +152,6 @@ event_forward_connection(event_ctx *ctx, int dest_fd)
                 rc = CON_IN_TERMINATED;
                 break;
             default:
-                buf[siz] = 0;
                 D2("Read %lu bytes from fd %d", siz, ev->data.fd);
                 break;
         }
@@ -159,6 +159,14 @@ event_forward_connection(event_ctx *ctx, int dest_fd)
         if (rc != CON_OK)
             break;
 
+        if (on_data &&
+            on_data(ctx, ev->data.fd, dest_fd, buf, siz, user_data))
+        {
+            W2("On data callback failed, not forwarding from %d to %d",
+                ev->data.fd, dest_fd);
+            continue;
+        }
+
         if (has_input) {
             siz = write(dest_fd, &buf[0], siz);
 
diff --git a/src/pevent.h b/src/pevent.h
index c7b61e1..d6927f6 100644
--- a/src/pevent.h
+++ b/src/pevent.h
@@ -21,6 +21,8 @@ typedef struct event_ctx {
 } event_ctx;
 
 typedef int (*on_event_cb) (event_ctx *ev_ctx, int fd, void *user_data);
+typedef int (*on_data_cb) (event_ctx *ev_ctx, int src_fd, int dst_fd,
+                           char *buf, size_t siz, void *user_data);
 
 
 void event_init(event_ctx **ctx);
@@ -36,6 +38,7 @@ int event_add_fd(event_ctx *ctx, int fd);
 int event_loop(event_ctx *ctx, on_event_cb on_event, void *user_data);
 
 forward_state
-event_forward_connection(event_ctx *ctx, int dest_fd);
+event_forward_connection(event_ctx *ctx, int dest_fd, on_data_cb on_data,
+                         void *user_data);
 
 #endif
diff --git a/src/redirector.c b/src/redirector.c
index c21fa61..4a577ca 100644
--- a/src/redirector.c
+++ b/src/redirector.c
@@ -353,7 +353,7 @@ client_io(event_ctx *ev_ctx, int src_fd, void *user_data)
         dest_fd = ev_cli->fwd_sock->fd;
     } else return 0;
 
-    fwd_state = event_forward_connection(ev_ctx, dest_fd);
+    fwd_state = event_forward_connection(ev_ctx, dest_fd, NULL, NULL);
 
     switch (fwd_state_string(fwd_state, ev_cli->client_args,
                              ev_cli->fwd_sock))
diff --git a/src/utils.c b/src/utils.c
index d63edcc..4c6224d 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <ctype.h>
 #include <stdarg.h>
 #include <fcntl.h>
 #include <signal.h>
@@ -25,6 +26,7 @@ char *arg0 = NULL;
 static int null_fd = -1;
 
 static void sighandler_child(int signo);
+static inline void bin2hex_char(unsigned char c, char hexc[5]);
 
 
 int set_fd_nonblock(int fd)
@@ -445,3 +447,52 @@ int update_setgroups_self(int allow)
     return 0;
 }
 #endif
+
+static inline void bin2hex_char(unsigned char c, char hexc[5])
+{
+    static const char hexalnum[] = "0123456789ABCDEF";
+
+    hexc[0] = '\\';
+    hexc[1] = 'x';
+    hexc[2] = hexalnum[ (c >> 4)%16 ];
+    hexc[3] = hexalnum[ (c & 0x0F)%16 ];
+    hexc[4] = 0;
+}
+
+void escape_ascii_string(const char ascii[], size_t siz, char **dest, size_t *newsiz)
+{
+    char hexbyte[5];
+    const size_t binsiz = 4;
+    size_t i, j, ns;
+
+    assert(ascii && dest && newsiz);
+
+    ns = 0;
+    for (i = 0; i < siz; ++i) {
+        if (isprint(ascii[i]))
+            ns++;
+        else
+            ns += binsiz;
+    }
+
+    if (ns > *newsiz) {
+        if (*dest)
+            free(*dest);
+        *dest = (char *) malloc(sizeof(char) * (ns+1));
+        assert(*dest);
+        (*newsiz) = ns;
+    }
+
+    for (i = 0, j = 0; i < siz && j < ns; ++i) {
+        if (isprint(ascii[i])) {
+            (*dest)[j] = ascii[i];
+            j++;
+        } else {
+            bin2hex_char(ascii[i], hexbyte);
+            snprintf((*dest)+j, binsiz+1, "%s", hexbyte);
+            j += binsiz;
+        }
+    }
+
+    (*dest)[ns] = 0;
+}
diff --git a/src/utils.h b/src/utils.h
index 8b3b230..3cd82e7 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -1,10 +1,14 @@
 #ifndef POTD_UTILS_H
 #define POTD_UTILS_H 1
 
+#include <stdlib.h>
+
 #ifndef SIZEOF
 #define SIZEOF(arr) (sizeof(arr)/sizeof(arr[0]))
 #endif
 
+#define MIN(x, y) (x > y ? y : x)
+
 extern char *arg0;
 
 
@@ -47,4 +51,7 @@ int update_guid_map(pid_t pid, unsigned int uid_map[3], int update_uidmap);
 int update_setgroups_self(int allow);
 #endif
 
+void escape_ascii_string(const char ascii[], size_t siz,
+                         char **dest, size_t *newsiz);
+
 #endif