connector/cn_proc: Selftest for proc connector

Run as ./proc_filter -f to run new filter code. Run without "-f" to run
usual proc connector code without the new filtering code.

Signed-off-by: Anjali Kulkarni <anjali.k.kulkarni@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Anjali Kulkarni 2023-07-19 13:18:21 -07:00 committed by David S. Miller
parent bfdfdc2f3b
commit 73a29531f4
3 changed files with 317 additions and 0 deletions

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@ -8,6 +8,7 @@ TARGETS += cachestat
TARGETS += capabilities
TARGETS += cgroup
TARGETS += clone3
TARGETS += connector
TARGETS += core
TARGETS += cpufreq
TARGETS += cpu-hotplug

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@ -0,0 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
CFLAGS += -Wall
TEST_GEN_PROGS = proc_filter
include ../lib.mk

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@ -0,0 +1,310 @@
// SPDX-License-Identifier: GPL-2.0-only
#include <sys/types.h>
#include <sys/epoll.h>
#include <sys/socket.h>
#include <linux/netlink.h>
#include <linux/connector.h>
#include <linux/cn_proc.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <strings.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include "../kselftest.h"
#define NL_MESSAGE_SIZE (sizeof(struct nlmsghdr) + sizeof(struct cn_msg) + \
sizeof(struct proc_input))
#define NL_MESSAGE_SIZE_NF (sizeof(struct nlmsghdr) + sizeof(struct cn_msg) + \
sizeof(int))
#define MAX_EVENTS 1
volatile static int interrupted;
static int nl_sock, ret_errno, tcount;
static struct epoll_event evn;
static int filter;
#ifdef ENABLE_PRINTS
#define Printf printf
#else
#define Printf ksft_print_msg
#endif
int send_message(void *pinp)
{
char buff[NL_MESSAGE_SIZE];
struct nlmsghdr *hdr;
struct cn_msg *msg;
hdr = (struct nlmsghdr *)buff;
if (filter)
hdr->nlmsg_len = NL_MESSAGE_SIZE;
else
hdr->nlmsg_len = NL_MESSAGE_SIZE_NF;
hdr->nlmsg_type = NLMSG_DONE;
hdr->nlmsg_flags = 0;
hdr->nlmsg_seq = 0;
hdr->nlmsg_pid = getpid();
msg = (struct cn_msg *)NLMSG_DATA(hdr);
msg->id.idx = CN_IDX_PROC;
msg->id.val = CN_VAL_PROC;
msg->seq = 0;
msg->ack = 0;
msg->flags = 0;
if (filter) {
msg->len = sizeof(struct proc_input);
((struct proc_input *)msg->data)->mcast_op =
((struct proc_input *)pinp)->mcast_op;
((struct proc_input *)msg->data)->event_type =
((struct proc_input *)pinp)->event_type;
} else {
msg->len = sizeof(int);
*(int *)msg->data = *(enum proc_cn_mcast_op *)pinp;
}
if (send(nl_sock, hdr, hdr->nlmsg_len, 0) == -1) {
ret_errno = errno;
perror("send failed");
return -3;
}
return 0;
}
int register_proc_netlink(int *efd, void *input)
{
struct sockaddr_nl sa_nl;
int err = 0, epoll_fd;
nl_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
if (nl_sock == -1) {
ret_errno = errno;
perror("socket failed");
return -1;
}
bzero(&sa_nl, sizeof(sa_nl));
sa_nl.nl_family = AF_NETLINK;
sa_nl.nl_groups = CN_IDX_PROC;
sa_nl.nl_pid = getpid();
if (bind(nl_sock, (struct sockaddr *)&sa_nl, sizeof(sa_nl)) == -1) {
ret_errno = errno;
perror("bind failed");
return -2;
}
epoll_fd = epoll_create1(EPOLL_CLOEXEC);
if (epoll_fd < 0) {
ret_errno = errno;
perror("epoll_create1 failed");
return -2;
}
err = send_message(input);
if (err < 0)
return err;
evn.events = EPOLLIN;
evn.data.fd = nl_sock;
if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, nl_sock, &evn) < 0) {
ret_errno = errno;
perror("epoll_ctl failed");
return -3;
}
*efd = epoll_fd;
return 0;
}
static void sigint(int sig)
{
interrupted = 1;
}
int handle_packet(char *buff, int fd, struct proc_event *event)
{
struct nlmsghdr *hdr;
hdr = (struct nlmsghdr *)buff;
if (hdr->nlmsg_type == NLMSG_ERROR) {
perror("NLMSG_ERROR error\n");
return -3;
} else if (hdr->nlmsg_type == NLMSG_DONE) {
event = (struct proc_event *)
((struct cn_msg *)NLMSG_DATA(hdr))->data;
tcount++;
switch (event->what) {
case PROC_EVENT_EXIT:
Printf("Exit process %d (tgid %d) with code %d, signal %d\n",
event->event_data.exit.process_pid,
event->event_data.exit.process_tgid,
event->event_data.exit.exit_code,
event->event_data.exit.exit_signal);
break;
case PROC_EVENT_FORK:
Printf("Fork process %d (tgid %d), parent %d (tgid %d)\n",
event->event_data.fork.child_pid,
event->event_data.fork.child_tgid,
event->event_data.fork.parent_pid,
event->event_data.fork.parent_tgid);
break;
case PROC_EVENT_EXEC:
Printf("Exec process %d (tgid %d)\n",
event->event_data.exec.process_pid,
event->event_data.exec.process_tgid);
break;
case PROC_EVENT_UID:
Printf("UID process %d (tgid %d) uid %d euid %d\n",
event->event_data.id.process_pid,
event->event_data.id.process_tgid,
event->event_data.id.r.ruid,
event->event_data.id.e.euid);
break;
case PROC_EVENT_GID:
Printf("GID process %d (tgid %d) gid %d egid %d\n",
event->event_data.id.process_pid,
event->event_data.id.process_tgid,
event->event_data.id.r.rgid,
event->event_data.id.e.egid);
break;
case PROC_EVENT_SID:
Printf("SID process %d (tgid %d)\n",
event->event_data.sid.process_pid,
event->event_data.sid.process_tgid);
break;
case PROC_EVENT_PTRACE:
Printf("Ptrace process %d (tgid %d), Tracer %d (tgid %d)\n",
event->event_data.ptrace.process_pid,
event->event_data.ptrace.process_tgid,
event->event_data.ptrace.tracer_pid,
event->event_data.ptrace.tracer_tgid);
break;
case PROC_EVENT_COMM:
Printf("Comm process %d (tgid %d) comm %s\n",
event->event_data.comm.process_pid,
event->event_data.comm.process_tgid,
event->event_data.comm.comm);
break;
case PROC_EVENT_COREDUMP:
Printf("Coredump process %d (tgid %d) parent %d, (tgid %d)\n",
event->event_data.coredump.process_pid,
event->event_data.coredump.process_tgid,
event->event_data.coredump.parent_pid,
event->event_data.coredump.parent_tgid);
break;
default:
break;
}
}
return 0;
}
int handle_events(int epoll_fd, struct proc_event *pev)
{
char buff[CONNECTOR_MAX_MSG_SIZE];
struct epoll_event ev[MAX_EVENTS];
int i, event_count = 0, err = 0;
event_count = epoll_wait(epoll_fd, ev, MAX_EVENTS, -1);
if (event_count < 0) {
ret_errno = errno;
if (ret_errno != EINTR)
perror("epoll_wait failed");
return -3;
}
for (i = 0; i < event_count; i++) {
if (!(ev[i].events & EPOLLIN))
continue;
if (recv(ev[i].data.fd, buff, sizeof(buff), 0) == -1) {
ret_errno = errno;
perror("recv failed");
return -3;
}
err = handle_packet(buff, ev[i].data.fd, pev);
if (err < 0)
return err;
}
return 0;
}
int main(int argc, char *argv[])
{
int epoll_fd, err;
struct proc_event proc_ev;
struct proc_input input;
signal(SIGINT, sigint);
if (argc > 2) {
printf("Expected 0(assume no-filter) or 1 argument(-f)\n");
exit(1);
}
if (argc == 2) {
if (strcmp(argv[1], "-f") == 0) {
filter = 1;
} else {
printf("Valid option : -f (for filter feature)\n");
exit(1);
}
}
if (filter) {
input.event_type = PROC_EVENT_NONZERO_EXIT;
input.mcast_op = PROC_CN_MCAST_LISTEN;
err = register_proc_netlink(&epoll_fd, (void*)&input);
} else {
enum proc_cn_mcast_op op = PROC_CN_MCAST_LISTEN;
err = register_proc_netlink(&epoll_fd, (void*)&op);
}
if (err < 0) {
if (err == -2)
close(nl_sock);
if (err == -3) {
close(nl_sock);
close(epoll_fd);
}
exit(1);
}
while (!interrupted) {
err = handle_events(epoll_fd, &proc_ev);
if (err < 0) {
if (ret_errno == EINTR)
continue;
if (err == -2)
close(nl_sock);
if (err == -3) {
close(nl_sock);
close(epoll_fd);
}
exit(1);
}
}
if (filter) {
input.mcast_op = PROC_CN_MCAST_IGNORE;
send_message((void*)&input);
} else {
enum proc_cn_mcast_op op = PROC_CN_MCAST_IGNORE;
send_message((void*)&op);
}
close(epoll_fd);
close(nl_sock);
printf("Done total count: %d\n", tcount);
exit(0);
}