Userland: Move command-line utilities to Userland/Utilities/

1 files changed, 234 insertions, 0 deletions

diff --git a/Userland/Utilities/nc.cpp b/Userland/Utilities/nc.cpp
new file mode 100644
index 0000000000..8d4f0a7613
--- /dev/null
+++ b/Userland/Utilities/nc.cpp
@@ -0,0 +1,234 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <LibCore/ArgsParser.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+int main(int argc, char** argv)
+{
+    bool should_listen = false;
+    bool verbose = false;
+    bool should_close = false;
+    const char* addr = nullptr;
+    int port = 0;
+
+    Core::ArgsParser args_parser;
+    args_parser.set_general_help("Network cat: Connect to network sockets as if it were a file.");
+    args_parser.add_option(should_listen, "Listen instead of connecting", "listen", 'l');
+    args_parser.add_option(verbose, "Log everything that's happening", "verbose", 'v');
+    args_parser.add_option(should_close, "Close connection after reading stdin to the end", nullptr, 'N');
+    args_parser.add_positional_argument(addr, "Address to connect to or listen on", "address");
+    args_parser.add_positional_argument(port, "Port to connect to or listen on", "port");
+    args_parser.parse(argc, argv);
+
+    int fd;
+
+    if (should_listen) {
+        int listen_fd = socket(AF_INET, SOCK_STREAM, 0);
+        if (listen_fd < 0) {
+            perror("socket");
+            return 1;
+        }
+
+        struct sockaddr_in sa;
+        memset(&sa, 0, sizeof sa);
+        sa.sin_family = AF_INET;
+        sa.sin_port = htons(port);
+        sa.sin_addr.s_addr = htonl(INADDR_ANY);
+        if (addr) {
+            if (inet_pton(AF_INET, addr, &sa.sin_addr) < 0) {
+                perror("inet_pton");
+                return 1;
+            }
+        }
+
+        if (bind(listen_fd, (struct sockaddr*)&sa, sizeof(sa)) == -1) {
+            perror("bind");
+            return 1;
+        }
+
+        if (listen(listen_fd, 1) == -1) {
+            perror("listen");
+            return 1;
+        }
+
+        char addr_str[100];
+
+        struct sockaddr_in sin;
+        socklen_t len;
+
+        len = sizeof(sin);
+        if (getsockname(listen_fd, (struct sockaddr*)&sin, &len) == -1) {
+            perror("getsockname");
+            return 1;
+        }
+        if (verbose)
+            fprintf(stderr, "waiting for a connection on %s:%d\n", inet_ntop(sin.sin_family, &sin.sin_addr, addr_str, sizeof(addr_str) - 1), ntohs(sin.sin_port));
+
+        len = sizeof(sin);
+        fd = accept(listen_fd, (struct sockaddr*)&sin, &len);
+        if (fd == -1) {
+            perror("accept");
+            return 1;
+        }
+
+        if (verbose)
+            fprintf(stderr, "got connection from %s:%d\n", inet_ntop(sin.sin_family, &sin.sin_addr, addr_str, sizeof(addr_str) - 1), ntohs(sin.sin_port));
+
+        if (close(listen_fd) == -1) {
+            perror("close");
+            return 1;
+        };
+    } else {
+        fd = socket(AF_INET, SOCK_STREAM, 0);
+        if (fd < 0) {
+            perror("socket");
+            return 1;
+        }
+
+        struct timeval timeout {
+            3, 0
+        };
+        if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout)) < 0) {
+            perror("setsockopt");
+            return 1;
+        }
+        if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout)) < 0) {
+            perror("setsockopt");
+            return 1;
+        }
+
+        char addr_str[100];
+
+        struct sockaddr_in dst_addr;
+        memset(&dst_addr, 0, sizeof(dst_addr));
+
+        dst_addr.sin_family = AF_INET;
+        dst_addr.sin_port = htons(port);
+        if (inet_pton(AF_INET, addr, &dst_addr.sin_addr) < 0) {
+            perror("inet_pton");
+            return 1;
+        }
+
+        if (verbose)
+            fprintf(stderr, "connecting to %s:%d\n", inet_ntop(dst_addr.sin_family, &dst_addr.sin_addr, addr_str, sizeof(addr_str) - 1), ntohs(dst_addr.sin_port));
+        if (connect(fd, (struct sockaddr*)&dst_addr, sizeof(dst_addr)) < 0) {
+            perror("connect");
+            return 1;
+        }
+        if (verbose)
+            fprintf(stderr, "connected!\n");
+    }
+
+    bool stdin_closed = false;
+    bool fd_closed = false;
+
+    fd_set readfds, writefds, exceptfds;
+
+    while (!stdin_closed || !fd_closed) {
+        FD_ZERO(&readfds);
+        FD_ZERO(&writefds);
+        FD_ZERO(&exceptfds);
+
+        int highest_fd = 0;
+
+        if (!stdin_closed) {
+            FD_SET(STDIN_FILENO, &readfds);
+            FD_SET(STDIN_FILENO, &exceptfds);
+            highest_fd = max(highest_fd, STDIN_FILENO);
+        }
+        if (!fd_closed) {
+            FD_SET(fd, &readfds);
+            FD_SET(fd, &exceptfds);
+            highest_fd = max(highest_fd, fd);
+        }
+
+        int ready = select(highest_fd + 1, &readfds, &writefds, &exceptfds, nullptr);
+        if (ready == -1) {
+            if (errno == EINTR)
+                continue;
+
+            perror("select");
+            return 1;
+        }
+
+        if (!stdin_closed && FD_ISSET(STDIN_FILENO, &readfds)) {
+            char buf[1024];
+            int nread = read(STDIN_FILENO, buf, sizeof(buf));
+            if (nread < 0) {
+                perror("read(STDIN_FILENO)");
+                return 1;
+            }
+
+            // stdin closed
+            if (nread == 0) {
+                stdin_closed = true;
+                if (verbose)
+                    fprintf(stderr, "stdin closed\n");
+                if (should_close) {
+                    close(fd);
+                    fd_closed = true;
+                }
+            } else if (write(fd, buf, nread) < 0) {
+                perror("write(fd)");
+                return 1;
+            }
+        }
+
+        if (!fd_closed && FD_ISSET(fd, &readfds)) {
+            char buf[1024];
+            int nread = read(fd, buf, sizeof(buf));
+            if (nread < 0) {
+                perror("read(fd)");
+                return 1;
+            }
+
+            // remote end closed
+            if (nread == 0) {
+                close(STDIN_FILENO);
+                stdin_closed = true;
+                fd_closed = true;
+                if (verbose)
+                    fprintf(stderr, "remote closed\n");
+            } else if (write(STDOUT_FILENO, buf, nread) < 0) {
+                perror("write(STDOUT_FILENO)");
+                return 1;
+            }
+        }
+    }
+
+    return 0;
+}