From 341c360a90a6698a11ffada0feb1527eb1b46a53 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sat, 18 Oct 2025 16:45:26 -0400 Subject: kern: Implement skeleton for POSIX sockets - Adds POSIX socket() - Adds POSIX listen() - Adds vnode socket type - Adds tmpfs socket awareness Much work is to be done but this commit provides a solid skeleton to be built upon. Signed-off-by: Ian Moffett --- src/sys/fs/tmpfs.c | 1 + src/sys/include/compat/unix/syscall.h | 5 +- src/sys/include/os/vnode.h | 2 + src/sys/include/sys/socket.h | 83 +++++++++++ src/sys/include/sys/syscall.h | 2 + src/sys/os/os_socket.c | 256 ++++++++++++++++++++++++++++++++++ 6 files changed, 348 insertions(+), 1 deletion(-) create mode 100644 src/sys/include/sys/socket.h create mode 100644 src/sys/os/os_socket.c diff --git a/src/sys/fs/tmpfs.c b/src/sys/fs/tmpfs.c index 9046002..3048fb4 100644 --- a/src/sys/fs/tmpfs.c +++ b/src/sys/fs/tmpfs.c @@ -203,6 +203,7 @@ tmpfs_create(struct vop_create_args *args) /* Only accept the types we support */ switch (args->vtype) { case VTYPE_FILE: + case VTYPE_SOCK: break; default: return -ENOTSUP; diff --git a/src/sys/include/compat/unix/syscall.h b/src/sys/include/compat/unix/syscall.h index 42dc4c0..38419af 100644 --- a/src/sys/include/compat/unix/syscall.h +++ b/src/sys/include/compat/unix/syscall.h @@ -31,6 +31,7 @@ #define _UNIX_SYSCALL_H_ 1 #include +#include #include #include #include @@ -95,7 +96,9 @@ scret_t(*g_unix_sctab[])(struct syscall_args *) = { [SYS_dmsio] = sys_dmsio, [SYS_read] = sys_read, [SYS_close] = sys_close, - [SYS_lseek] = sys_lseek + [SYS_lseek] = sys_lseek, + [SYS_socket] = sys_socket, + [SYS_listen] = sys_listen }; #endif /* !_NEED_UNIX_SCTAB */ diff --git a/src/sys/include/os/vnode.h b/src/sys/include/os/vnode.h index 31cfb0c..8cdcded 100644 --- a/src/sys/include/os/vnode.h +++ b/src/sys/include/os/vnode.h @@ -44,12 +44,14 @@ struct vop; * @VTYPE_NONE: Vnode is yet to be assigned a type * @VTYPE_FILE: Vnode references a file * @VTYPE_DIR: Vnode references a directory + * @VTYPE_SOCK: Vnode references a socket * @__N_VTYPE: Number of valid nodes on the system */ typedef enum { VTYPE_NONE, VTYPE_FILE, VTYPE_DIR, + VTYPE_SOCK, __N_VTYPE } vtype_t; diff --git a/src/sys/include/sys/socket.h b/src/sys/include/sys/socket.h new file mode 100644 index 0000000..0ca041f --- /dev/null +++ b/src/sys/include/sys/socket.h @@ -0,0 +1,83 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and L5 engineers + * 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. + * 3. Neither the name of the project nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * 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 OWNER 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. + */ + +#ifndef _SYS_SOCKET_H_ +#define _SYS_SOCKET_H_ 1 + +#include +#include + +/* Address family defines */ +#define AF_UNIX 0x00 /* Local comms / IPC */ +#define AF_LOCAL AF_UNIX /* AF_UNIX alias */ + +/* Socket type defines */ +#define SOCK_STREAM 0x00 +#define SOCK_DGRAM 0x01 + +/* + * Get a socket as a file descriptor + * + * @domain: Socket domain (AF_*) + * @type: Socket type SOCK_* + * + * Returns file descriptor on success, otherwise + * a less than zero value on failure + */ +int socket(int domain, int type, int protocol); + +/* + * @socket: Socket to listen on + * @backlog: Max connections + */ +int listen(int socket, int backlog); + +#if defined(_KERNEL) + +/* + * Kernel representation of a socket + * + * @backlog: Maximum connections (< 0 means socket not active) + */ +struct ksocket { + int backlog; +}; + +/* + * Socket syscall + */ +scret_t sys_socket(struct syscall_args *scargs); + +/* + * Listen syscall + */ +scret_t sys_listen(struct syscall_args *scargs); + +#endif /* _KERNEL */ +#endif /* !_SYS_SOCKET_H_ */ diff --git a/src/sys/include/sys/syscall.h b/src/sys/include/sys/syscall.h index c97d5ea..2ca712f 100644 --- a/src/sys/include/sys/syscall.h +++ b/src/sys/include/sys/syscall.h @@ -59,6 +59,8 @@ #define SYS_read 0x0E /* read a file descriptor */ #define SYS_close 0x0F /* close a file */ #define SYS_lseek 0x10 /* seek to end of file */ +#define SYS_socket 0x11 /* get a socket fd */ +#define SYS_listen 0x12 /* listen on a socket */ typedef __ssize_t scret_t; typedef __ssize_t scarg_t; diff --git a/src/sys/os/os_socket.c b/src/sys/os/os_socket.c new file mode 100644 index 0000000..a37d15f --- /dev/null +++ b/src/sys/os/os_socket.c @@ -0,0 +1,256 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and L5 engineers + * 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. + * 3. Neither the name of the project nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * 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 OWNER 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 +#include +#include +#include +#include +#include +#include +#include +#include + +static size_t next_sockid = 1; + +/* + * Allocate a socket file descriptor + * + * @fdp_res: Result is written here + * + * XXX: Socket vnodes are never deallocated until explicitly + * closed + * + * Returns file descriptor on success, otherwise a + * less than zero value on faulure + */ +static int +get_sock_fd(struct filedesc **fdp_res) +{ + char namebuf[256]; + struct ksocket *sock; + struct mount *mp; + struct nameidata nd; + struct filedesc *fdp; + struct proc *self = proc_self(); + struct vnode *vp; + int error; + + if (fdp_res == NULL) { + return -EINVAL; + } + + if (self == NULL) { + return -EIO; + } + + error = mount_lookup("/tmp", &mp); + if (error < 0) { + printf("socket: could not get /tmp mountpoint\n"); + return error; + } + + error = fd_alloc(self, &fdp); + if (error < 0) { + printf("socket: could not allocate fd\n"); + return error; + } + + sock = kalloc(sizeof(*sock)); + if (sock == NULL) { + fd_close(fdp->fdno); + return -EINVAL; + } + + /* Format the name */ + snprintf( + namebuf, + sizeof(namebuf), + "sock.%d", + next_sockid++ + ); + + /* Allocate a persistent vnode */ + error = vfs_valloc(&vp, VTYPE_SOCK, 0); + if (error < 0) { + printf("socket: could not allocate vnode\n"); + fd_close(fdp->fdno); + kfree(sock); + return error; + } + + /* Create the backing file */ + nd.path = namebuf; + error = vop_create(mp->vp, &nd, VTYPE_SOCK); + if (error < 0) { + printf("socket: failed to create /tmp entry\n"); + fd_close(fdp->fdno); + kfree(sock); + return error; + } + + /* Mark the socket as inactive */ + memset(sock, 0, sizeof(*sock)); + sock->backlog = -1; + + fdp->vp = vp; + vp->data = sock; + printf("socket: socket created @ /tmp/%s\n", namebuf); + return fdp->fdno; +} + +/* + * Get a socket descriptor from a fd + * + * @fd: File descriptor to look up + * @sock_res: Result pointer is written here + * + * Returns zero on success, otherwise a less + * than zero value on failure + */ +static int +get_sock(int fd, struct ksocket **sock_res) +{ + struct filedesc *fdp; + struct proc *self = proc_self(); + struct vnode *vp; + + if (fd < 0) { + return -EBADF; + } + + if (sock_res == NULL) { + return -1; + } + + if (self == NULL) { + return -EINVAL; + } + + /* Get the file descriptor */ + fdp = fd_get( + self, + fd + ); + + if (fdp == NULL) { + return -EBADF; + } + + /* We need the vnode */ + if ((vp = fdp->vp) == NULL) { + return -EIO; + } + + *sock_res = vp->data; + return 0; +} + +/* + * Any backlog value > 0 marks the socket + * as accepting connections + */ +int +listen(int socket, int backlog) +{ + struct ksocket *ksock = NULL; + int error; + + if (socket < 0) { + return -EBADF; + } + + if (backlog < 0) { + backlog = 0; + } + + error = get_sock(socket, &ksock); + if (error < 0) { + printf("listen: failed to get socket descriptor\n"); + return error; + } + + /* Set the backlog */ + ksock->backlog = backlog; + return 0; +} + +/* + * Handles the AF_UNIX domain + */ +static int +af_unix(int type, int protocol) +{ + struct filedesc *desc; + + return get_sock_fd(&desc); +} + +int +socket(int domain, int type, int protocol) +{ + if (domain < 0 || type < 0) { + return -EINVAL; + } + + switch (domain) { + case AF_UNIX: + return af_unix(type, protocol); + } + + return -1; +} + +/* + * ARG0: Domain + * ARG1: Type + * ARG2: Protocol + */ +scret_t +sys_socket(struct syscall_args *scargs) +{ + int domain = SCARG(scargs, int, 0); + int type = SCARG(scargs, int, 1); + int protocol = SCARG(scargs, int, 2); + + return socket(domain, type, protocol); +} + +/* + * ARG0: Socket fd + * @backlog: Maximum connections + */ +scret_t +sys_listen(struct syscall_args *scargs) +{ + int sockfd = SCARG(scargs, int, 0); + int backlog = SCARG(scargs, int, 1); + + return listen(sockfd, backlog); +} -- cgit v1.2.3