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/*
All files except if stated otherwise in the begining of the file
are under the ISC license:
----------------------------------------------------------------------
Copyright (c) 2010-2012 Design Art Networks Ltd.
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/ioctl.h>
#include "danipc_k.h"
#include "ipc_api.h"
#include "danipc_lowlevel.h"
struct agent_data {
struct task_struct *task;
pid_t pid;
};
struct agent_data agent_data[MAX_LOCAL_AGENT];
static int
is_process_alive(const struct agent_data *agent_data_p)
{
int rc = 0;
struct task_struct *task = find_task_by_vpid(agent_data_p->pid);
if (task) {
/* Paranoid check: task_struct exists, now verify it belongs
* to the correct process.
*/
if (agent_data_p->task == task &&
agent_data_p->pid == task->pid)
rc = 1;
}
return rc;
}
static void
ipc_gc(void)
{
unsigned lid;
for (lid = 0; lid < MAX_LOCAL_AGENT; lid++) {
struct agent_data *agent_data_p = &agent_data[lid];
if (agent_data_p->task && !is_process_alive(agent_data_p)) {
agent_data_p->task = NULL;
agent_data_p->pid = 0;
}
}
}
static int
danipc_strncmp(const char *cs, const char *ct, size_t cs_size, size_t ct_size)
{
return ((strnlen(cs, cs_size) == strnlen(ct, ct_size)) &&
(strcmp(cs, ct) == 0));
}
/* Second registration is allowed only for the same process. */
static int
second_registration(struct danipc_reg *danipc_reg_p, const int aid,
const unsigned lid)
{
return (danipc_strncmp(agent_table[aid].name, danipc_reg_p->name,
MAX_AGENT_NAME_LEN, MAX_AGENT_NAME) &&
agent_data[lid].task == current) ? 1 : 0;
}
static int
register_agent(struct net_device *dev, struct danipc_reg *danipc_reg_p)
{
struct danipc_reg danipc_reg;
unsigned r_lid;
unsigned agent_id = INVALID_ID;
int rc = 0;
ipc_gc();
if (copy_from_user(&danipc_reg, danipc_reg_p, sizeof(danipc_reg)))
return -EFAULT;
r_lid = danipc_reg.requested_lid;
if (r_lid != INVALID_ID) {
const unsigned r_aid = __IPC_AGENT_ID(LOCAL_IPC_ID, r_lid);
/* Requested ID is not used, so assign it */
if (!*agent_table[r_aid].name ||
second_registration(&danipc_reg, r_aid, r_lid) ||
(danipc_strncmp(danipc_reg.name,
agent_table[r_aid].name,
MAX_AGENT_NAME, MAX_AGENT_NAME_LEN) &&
agent_data[r_lid].task == NULL)) {
if (put_user(r_lid, &danipc_reg_p->assigned_lid))
return -EFAULT;
agent_id = r_aid;
}
}
if (agent_id == INVALID_ID) {
unsigned lid;
/* Scan for the ID already assigned */
for (lid = 0; lid < MAX_LOCAL_AGENT; lid++) {
const unsigned aid = __IPC_AGENT_ID(LOCAL_IPC_ID, lid);
if (danipc_strncmp(danipc_reg.name,
agent_table[aid].name,
MAX_AGENT_NAME, MAX_AGENT_NAME_LEN)
&& agent_data[lid].task == NULL) {
if (put_user(lid, &danipc_reg_p->assigned_lid))
return -EFAULT;
agent_id = aid;
break;
}
}
}
if (agent_id == INVALID_ID) {
unsigned lid;
/* Scan for the 1st free ID */
for (lid = 0; lid < MAX_LOCAL_AGENT; lid++) {
const unsigned aid = __IPC_AGENT_ID(LOCAL_IPC_ID, lid);
if (!*agent_table[aid].name ||
second_registration(&danipc_reg, aid, lid)) {
if (put_user(lid, &danipc_reg_p->assigned_lid))
return -EFAULT;
agent_id = aid;
break;
}
}
}
if (agent_id != INVALID_ID) {
const unsigned an_siz = sizeof(agent_table[agent_id].name);
const uint16_t cookie = cpu_to_be16(AGENTID_TO_COOKIE(agent_id,
danipc_reg.prio));
strlcpy(agent_table[agent_id].name, danipc_reg.name,
an_siz);
agent_table[agent_id].name[an_siz-1] = 0;
if (put_user(cookie, &danipc_reg_p->cookie))
rc = -EFAULT;
agent_data[ipc_lid(agent_id)].task = current;
agent_data[ipc_lid(agent_id)].pid = current->pid;
netdev_dbg(dev,
"%s: agent_id=0x%x assigned_lid=0x%x agent_table[]=\"%s\"\n",
__func__, agent_id, danipc_reg.assigned_lid,
agent_table[agent_id].name);
} else
rc = -ENOBUFS;
return rc;
}
static int
get_name_by_addr(struct net_device *dev, struct danipc_name *danipc_name_p)
{
int rc = -ENODATA;
danipc_addr_t addr;
if (get_user(addr, &danipc_name_p->addr))
return -EFAULT;
if (*agent_table[addr].name) {
if (copy_to_user(danipc_name_p->name,
agent_table[danipc_name_p->addr].name,
sizeof(danipc_name_p->name)))
rc = -EFAULT;
else
rc = 0;
netdev_dbg(dev, "%s(): addr=0x%x -> name=%s\n", __func__,
addr, agent_table[danipc_name_p->addr].name);
}
return rc;
}
static int
get_addr_by_name(struct net_device *dev, struct danipc_name *danipc_name_p)
{
char name[MAX_AGENT_NAME];
int rc = -ENODATA;
unsigned aid;
if (copy_from_user(name, danipc_name_p->name, sizeof(name)))
return -EFAULT;
for (aid = 0; aid < MAX_AGENTS; aid++) {
if (danipc_strncmp(name, agent_table[aid].name,
MAX_AGENT_NAME, MAX_AGENT_NAME_LEN)) {
const unsigned cpuid = aid / MAX_LOCAL_AGENT;
const unsigned lid = aid % MAX_LOCAL_AGENT;
if (put_user(__IPC_AGENT_ID(cpuid, lid),
&danipc_name_p->addr))
rc = -EFAULT;
else
rc = 0;
netdev_dbg(dev, "%s: name=%s -> addr=0x%x\n", __func__,
agent_table[aid].name, aid);
}
}
return rc;
}
int danipc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
int rc = -EINVAL;
if (dev && ifr && ifr->ifr_data) {
struct danipc_priv *priv = netdev_priv(dev);
mutex_lock(&priv->lock);
switch (cmd) {
case DANIPC_IOCS_REGISTER:
rc = register_agent(dev,
(struct danipc_reg *)ifr->ifr_data);
break;
case DANIPC_IOCG_ADDR2NAME:
rc = get_name_by_addr(dev,
(struct danipc_name *)ifr->ifr_data);
break;
case DANIPC_IOCG_NAME2ADDR:
rc = get_addr_by_name(dev,
(struct danipc_name *)ifr->ifr_data);
break;
}
mutex_unlock(&priv->lock);
}
return rc;
}
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