From 4a327fcef90ba27150a3e8741441b68c605ae248 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Sat, 26 Mar 2016 05:33:09 -0300 Subject: Add TuxOnIce support adapted for the 4.5-gnu kernel version --- kernel/power/tuxonice_netlink.c | 324 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 324 insertions(+) create mode 100644 kernel/power/tuxonice_netlink.c (limited to 'kernel/power/tuxonice_netlink.c') diff --git a/kernel/power/tuxonice_netlink.c b/kernel/power/tuxonice_netlink.c new file mode 100644 index 000000000..78bd31b05 --- /dev/null +++ b/kernel/power/tuxonice_netlink.c @@ -0,0 +1,324 @@ +/* + * kernel/power/tuxonice_netlink.c + * + * Copyright (C) 2004-2015 Nigel Cunningham (nigel at nigelcunningham com au) + * + * This file is released under the GPLv2. + * + * Functions for communicating with a userspace helper via netlink. + */ + +#include +#include +#include +#include "tuxonice_netlink.h" +#include "tuxonice.h" +#include "tuxonice_modules.h" +#include "tuxonice_alloc.h" +#include "tuxonice_builtin.h" + +static struct user_helper_data *uhd_list; + +/* + * Refill our pool of SKBs for use in emergencies (eg, when eating memory and + * none can be allocated). + */ +static void toi_fill_skb_pool(struct user_helper_data *uhd) +{ + while (uhd->pool_level < uhd->pool_limit) { + struct sk_buff *new_skb = + alloc_skb(NLMSG_SPACE(uhd->skb_size), TOI_ATOMIC_GFP); + + if (!new_skb) + break; + + new_skb->next = uhd->emerg_skbs; + uhd->emerg_skbs = new_skb; + uhd->pool_level++; + } +} + +/* + * Try to allocate a single skb. If we can't get one, try to use one from + * our pool. + */ +static struct sk_buff *toi_get_skb(struct user_helper_data *uhd) +{ + struct sk_buff *skb = + alloc_skb(NLMSG_SPACE(uhd->skb_size), TOI_ATOMIC_GFP); + + if (skb) + return skb; + + skb = uhd->emerg_skbs; + if (skb) { + uhd->pool_level--; + uhd->emerg_skbs = skb->next; + skb->next = NULL; + } + + return skb; +} + +void toi_send_netlink_message(struct user_helper_data *uhd, + int type, void *params, size_t len) +{ + struct sk_buff *skb; + struct nlmsghdr *nlh; + void *dest; + struct task_struct *t; + + if (uhd->pid == -1) + return; + + if (uhd->debug) + printk(KERN_ERR "toi_send_netlink_message: Send " + "message type %d.\n", type); + + skb = toi_get_skb(uhd); + if (!skb) { + printk(KERN_INFO "toi_netlink: Can't allocate skb!\n"); + return; + } + + nlh = nlmsg_put(skb, 0, uhd->sock_seq, type, len, 0); + uhd->sock_seq++; + + dest = NLMSG_DATA(nlh); + if (params && len > 0) + memcpy(dest, params, len); + + netlink_unicast(uhd->nl, skb, uhd->pid, 0); + + toi_read_lock_tasklist(); + t = find_task_by_pid_ns(uhd->pid, &init_pid_ns); + if (!t) { + toi_read_unlock_tasklist(); + if (uhd->pid > -1) + printk(KERN_INFO "Hmm. Can't find the userspace task" + " %d.\n", uhd->pid); + return; + } + wake_up_process(t); + toi_read_unlock_tasklist(); + + yield(); +} + +static void send_whether_debugging(struct user_helper_data *uhd) +{ + static u8 is_debugging = 1; + + toi_send_netlink_message(uhd, NETLINK_MSG_IS_DEBUGGING, + &is_debugging, sizeof(u8)); +} + +/* + * Set the PF_NOFREEZE flag on the given process to ensure it can run whilst we + * are hibernating. + */ +static int nl_set_nofreeze(struct user_helper_data *uhd, __u32 pid) +{ + struct task_struct *t; + + if (uhd->debug) + printk(KERN_ERR "nl_set_nofreeze for pid %d.\n", pid); + + toi_read_lock_tasklist(); + t = find_task_by_pid_ns(pid, &init_pid_ns); + if (!t) { + toi_read_unlock_tasklist(); + printk(KERN_INFO "Strange. Can't find the userspace task %d.\n", + pid); + return -EINVAL; + } + + t->flags |= PF_NOFREEZE; + + toi_read_unlock_tasklist(); + uhd->pid = pid; + + toi_send_netlink_message(uhd, NETLINK_MSG_NOFREEZE_ACK, NULL, 0); + + return 0; +} + +/* + * Called when the userspace process has informed us that it's ready to roll. + */ +static int nl_ready(struct user_helper_data *uhd, u32 version) +{ + if (version != uhd->interface_version) { + printk(KERN_INFO "%s userspace process using invalid interface" + " version (%d - kernel wants %d). Trying to " + "continue without it.\n", + uhd->name, version, uhd->interface_version); + if (uhd->not_ready) + uhd->not_ready(); + return -EINVAL; + } + + complete(&uhd->wait_for_process); + + return 0; +} + +void toi_netlink_close_complete(struct user_helper_data *uhd) +{ + if (uhd->nl) { + netlink_kernel_release(uhd->nl); + uhd->nl = NULL; + } + + while (uhd->emerg_skbs) { + struct sk_buff *next = uhd->emerg_skbs->next; + kfree_skb(uhd->emerg_skbs); + uhd->emerg_skbs = next; + } + + uhd->pid = -1; +} + +static int toi_nl_gen_rcv_msg(struct user_helper_data *uhd, + struct sk_buff *skb, struct nlmsghdr *nlh) +{ + int type = nlh->nlmsg_type; + int *data; + int err; + + if (uhd->debug) + printk(KERN_ERR "toi_user_rcv_skb: Received message %d.\n", + type); + + /* Let the more specific handler go first. It returns + * 1 for valid messages that it doesn't know. */ + err = uhd->rcv_msg(skb, nlh); + if (err != 1) + return err; + + /* Only allow one task to receive NOFREEZE privileges */ + if (type == NETLINK_MSG_NOFREEZE_ME && uhd->pid != -1) { + printk(KERN_INFO "Received extra nofreeze me requests.\n"); + return -EBUSY; + } + + data = NLMSG_DATA(nlh); + + switch (type) { + case NETLINK_MSG_NOFREEZE_ME: + return nl_set_nofreeze(uhd, nlh->nlmsg_pid); + case NETLINK_MSG_GET_DEBUGGING: + send_whether_debugging(uhd); + return 0; + case NETLINK_MSG_READY: + if (nlh->nlmsg_len != NLMSG_LENGTH(sizeof(u32))) { + printk(KERN_INFO "Invalid ready mesage.\n"); + if (uhd->not_ready) + uhd->not_ready(); + return -EINVAL; + } + return nl_ready(uhd, (u32) *data); + case NETLINK_MSG_CLEANUP: + toi_netlink_close_complete(uhd); + return 0; + } + + return -EINVAL; +} + +static void toi_user_rcv_skb(struct sk_buff *skb) +{ + int err; + struct nlmsghdr *nlh; + struct user_helper_data *uhd = uhd_list; + + while (uhd && uhd->netlink_id != skb->sk->sk_protocol) + uhd = uhd->next; + + if (!uhd) + return; + + while (skb->len >= NLMSG_SPACE(0)) { + u32 rlen; + + nlh = (struct nlmsghdr *) skb->data; + if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) + return; + + rlen = NLMSG_ALIGN(nlh->nlmsg_len); + if (rlen > skb->len) + rlen = skb->len; + + err = toi_nl_gen_rcv_msg(uhd, skb, nlh); + if (err) + netlink_ack(skb, nlh, err); + else if (nlh->nlmsg_flags & NLM_F_ACK) + netlink_ack(skb, nlh, 0); + skb_pull(skb, rlen); + } +} + +static int netlink_prepare(struct user_helper_data *uhd) +{ + struct netlink_kernel_cfg cfg = { + .groups = 0, + .input = toi_user_rcv_skb, + }; + + uhd->next = uhd_list; + uhd_list = uhd; + + uhd->sock_seq = 0x42c0ffee; + uhd->nl = netlink_kernel_create(&init_net, uhd->netlink_id, &cfg); + if (!uhd->nl) { + printk(KERN_INFO "Failed to allocate netlink socket for %s.\n", + uhd->name); + return -ENOMEM; + } + + toi_fill_skb_pool(uhd); + + return 0; +} + +void toi_netlink_close(struct user_helper_data *uhd) +{ + struct task_struct *t; + + toi_read_lock_tasklist(); + t = find_task_by_pid_ns(uhd->pid, &init_pid_ns); + if (t) + t->flags &= ~PF_NOFREEZE; + toi_read_unlock_tasklist(); + + toi_send_netlink_message(uhd, NETLINK_MSG_CLEANUP, NULL, 0); +} +int toi_netlink_setup(struct user_helper_data *uhd) +{ + /* In case userui didn't cleanup properly on us */ + toi_netlink_close_complete(uhd); + + if (netlink_prepare(uhd) < 0) { + printk(KERN_INFO "Netlink prepare failed.\n"); + return 1; + } + + if (toi_launch_userspace_program(uhd->program, uhd->netlink_id, + UMH_WAIT_EXEC, uhd->debug) < 0) { + printk(KERN_INFO "Launch userspace program failed.\n"); + toi_netlink_close_complete(uhd); + return 1; + } + + /* Wait 2 seconds for the userspace process to make contact */ + wait_for_completion_timeout(&uhd->wait_for_process, 2*HZ); + + if (uhd->pid == -1) { + printk(KERN_INFO "%s: Failed to contact userspace process.\n", + uhd->name); + toi_netlink_close_complete(uhd); + return 1; + } + + return 0; +} -- cgit v1.2.3