diff options
Diffstat (limited to 'arch/um/drivers/mconsole_user.c')
| -rw-r--r-- | arch/um/drivers/mconsole_user.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/arch/um/drivers/mconsole_user.c b/arch/um/drivers/mconsole_user.c new file mode 100644 index 000000000..e24298a73 --- /dev/null +++ b/arch/um/drivers/mconsole_user.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) + * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + */ + +#include <errno.h> +#include <string.h> +#include <unistd.h> +#include <sys/socket.h> +#include <sys/uio.h> +#include <sys/un.h> +#include "mconsole.h" + +static struct mconsole_command commands[] = { + /* + * With uts namespaces, uts information becomes process-specific, so + * we need a process context. If we try handling this in interrupt + * context, we may hit an exiting process without a valid uts + * namespace. + */ + { "version", mconsole_version, MCONSOLE_PROC }, + { "halt", mconsole_halt, MCONSOLE_PROC }, + { "reboot", mconsole_reboot, MCONSOLE_PROC }, + { "config", mconsole_config, MCONSOLE_PROC }, + { "remove", mconsole_remove, MCONSOLE_PROC }, + { "sysrq", mconsole_sysrq, MCONSOLE_INTR }, + { "help", mconsole_help, MCONSOLE_INTR }, + { "cad", mconsole_cad, MCONSOLE_INTR }, + { "stop", mconsole_stop, MCONSOLE_PROC }, + { "go", mconsole_go, MCONSOLE_INTR }, + { "log", mconsole_log, MCONSOLE_INTR }, + { "proc", mconsole_proc, MCONSOLE_PROC }, + { "stack", mconsole_stack, MCONSOLE_INTR }, +}; + +/* Initialized in mconsole_init, which is an initcall */ +char mconsole_socket_name[256]; + +static int mconsole_reply_v0(struct mc_request *req, char *reply) +{ + struct iovec iov; + struct msghdr msg; + + iov.iov_base = reply; + iov.iov_len = strlen(reply); + + msg.msg_name = &(req->origin); + msg.msg_namelen = req->originlen; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = 0; + + return sendmsg(req->originating_fd, &msg, 0); +} + +static struct mconsole_command *mconsole_parse(struct mc_request *req) +{ + struct mconsole_command *cmd; + int i; + + for (i = 0; i < ARRAY_SIZE(commands); i++) { + cmd = &commands[i]; + if (!strncmp(req->request.data, cmd->command, + strlen(cmd->command))) { + return cmd; + } + } + return NULL; +} + +#define MIN(a,b) ((a)<(b) ? (a):(b)) + +#define STRINGX(x) #x +#define STRING(x) STRINGX(x) + +int mconsole_get_request(int fd, struct mc_request *req) +{ + int len; + + req->originlen = sizeof(req->origin); + req->len = recvfrom(fd, &req->request, sizeof(req->request), 0, + (struct sockaddr *) req->origin, &req->originlen); + if (req->len < 0) + return 0; + + req->originating_fd = fd; + + if (req->request.magic != MCONSOLE_MAGIC) { + /* Unversioned request */ + len = MIN(sizeof(req->request.data) - 1, + strlen((char *) &req->request)); + memmove(req->request.data, &req->request, len); + req->request.data[len] = '\0'; + + req->request.magic = MCONSOLE_MAGIC; + req->request.version = 0; + req->request.len = len; + + mconsole_reply_v0(req, "ERR Version 0 mconsole clients are " + "not supported by this driver"); + return 0; + } + + if (req->request.len >= MCONSOLE_MAX_DATA) { + mconsole_reply(req, "Request too large", 1, 0); + return 0; + } + if (req->request.version != MCONSOLE_VERSION) { + mconsole_reply(req, "This driver only supports version " + STRING(MCONSOLE_VERSION) " clients", 1, 0); + } + + req->request.data[req->request.len] = '\0'; + req->cmd = mconsole_parse(req); + if (req->cmd == NULL) { + mconsole_reply(req, "Unknown command", 1, 0); + return 0; + } + + return 1; +} + +int mconsole_reply_len(struct mc_request *req, const char *str, int total, + int err, int more) +{ + /* + * XXX This is a stack consumption problem. It'd be nice to + * make it global and serialize access to it, but there are a + * ton of callers to this function. + */ + struct mconsole_reply reply; + int len, n; + + do { + reply.err = err; + + /* err can only be true on the first packet */ + err = 0; + + len = MIN(total, MCONSOLE_MAX_DATA - 1); + + if (len == total) reply.more = more; + else reply.more = 1; + + memcpy(reply.data, str, len); + reply.data[len] = '\0'; + total -= len; + str += len; + reply.len = len + 1; + + len = sizeof(reply) + reply.len - sizeof(reply.data); + + n = sendto(req->originating_fd, &reply, len, 0, + (struct sockaddr *) req->origin, req->originlen); + + if (n < 0) + return -errno; + } while (total > 0); + return 0; +} + +int mconsole_reply(struct mc_request *req, const char *str, int err, int more) +{ + return mconsole_reply_len(req, str, strlen(str), err, more); +} + + +int mconsole_unlink_socket(void) +{ + unlink(mconsole_socket_name); + return 0; +} + +static int notify_sock = -1; + +int mconsole_notify(char *sock_name, int type, const void *data, int len) +{ + struct sockaddr_un target; + struct mconsole_notify packet; + int n, err = 0; + + lock_notify(); + if (notify_sock < 0) { + notify_sock = socket(PF_UNIX, SOCK_DGRAM, 0); + if (notify_sock < 0) { + err = -errno; + printk(UM_KERN_ERR "mconsole_notify - socket failed, " + "errno = %d\n", errno); + } + } + unlock_notify(); + + if (err) + return err; + + target.sun_family = AF_UNIX; + strcpy(target.sun_path, sock_name); + + packet.magic = MCONSOLE_MAGIC; + packet.version = MCONSOLE_VERSION; + packet.type = type; + len = (len > sizeof(packet.data)) ? sizeof(packet.data) : len; + packet.len = len; + memcpy(packet.data, data, len); + + err = 0; + len = sizeof(packet) + packet.len - sizeof(packet.data); + n = sendto(notify_sock, &packet, len, 0, (struct sockaddr *) &target, + sizeof(target)); + if (n < 0) { + err = -errno; + printk(UM_KERN_ERR "mconsole_notify - sendto failed, " + "errno = %d\n", errno); + } + return err; +} |