diff options
| -rw-r--r-- | fs/nsfs.c | 14 | ||||
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | include/linux/proc_ns.h | 2 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 20 | ||||
| -rw-r--r-- | kernel/bpf/core.c | 1 | ||||
| -rw-r--r-- | kernel/bpf/helpers.c | 45 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 2 | ||||
| -rwxr-xr-x | scripts/bpf_helpers_doc.py | 1 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 20 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/.gitignore | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/Makefile | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c | 88 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c | 37 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/test_current_pid_tgid_new_ns.c | 159 |
14 files changed, 391 insertions, 3 deletions
diff --git a/fs/nsfs.c b/fs/nsfs.c index b13bfd406820..4f1205725cfe 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -247,6 +247,20 @@ out_invalid: return ERR_PTR(-EINVAL); } +/** + * ns_match() - Returns true if current namespace matches dev/ino provided. + * @ns_common: current ns + * @dev: dev_t from nsfs that will be matched against current nsfs + * @ino: ino_t from nsfs that will be matched against current nsfs + * + * Return: true if dev and ino matches the current nsfs. + */ +bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino) +{ + return (ns->inum == ino) && (nsfs_mnt->mnt_sb->s_dev == dev); +} + + static int nsfs_show_path(struct seq_file *seq, struct dentry *dentry) { struct inode *inode = d_inode(dentry); diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 4fd91b7c95ea..4ec835334a1f 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1497,6 +1497,7 @@ extern const struct bpf_func_proto bpf_strtol_proto; extern const struct bpf_func_proto bpf_strtoul_proto; extern const struct bpf_func_proto bpf_tcp_sock_proto; extern const struct bpf_func_proto bpf_jiffies64_proto; +extern const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto; /* Shared helpers among cBPF and eBPF. */ void bpf_user_rnd_init_once(void); diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 4626b1ac3b6c..adff08bfecf9 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -85,6 +85,8 @@ typedef struct ns_common *ns_get_path_helper_t(void *); extern int ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb, void *private_data); +extern bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino); + extern int ns_get_name(char *buf, size_t size, struct task_struct *task, const struct proc_ns_operations *ns_ops); extern void nsfs_init(void); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 40b2d9476268..15b239da775b 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2914,6 +2914,19 @@ union bpf_attr { * of sizeof(struct perf_branch_entry). * * **-ENOENT** if architecture does not support branch records. + * + * int bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size) + * Description + * Returns 0 on success, values for *pid* and *tgid* as seen from the current + * *namespace* will be returned in *nsdata*. + * + * On failure, the returned value is one of the following: + * + * **-EINVAL** if dev and inum supplied don't match dev_t and inode number + * with nsfs of current task, or if dev conversion to dev_t lost high bits. + * + * **-ENOENT** if pidns does not exists for the current task. + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3035,7 +3048,8 @@ union bpf_attr { FN(tcp_send_ack), \ FN(send_signal_thread), \ FN(jiffies64), \ - FN(read_branch_records), + FN(read_branch_records), \ + FN(get_ns_current_pid_tgid), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -3829,4 +3843,8 @@ struct bpf_sockopt { __s32 retval; }; +struct bpf_pidns_info { + __u32 pid; + __u32 tgid; +}; #endif /* _UAPI__LINUX_BPF_H__ */ diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 973a20d49749..0f9ca46e1978 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2149,6 +2149,7 @@ const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; const struct bpf_func_proto bpf_get_current_comm_proto __weak; const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak; const struct bpf_func_proto bpf_get_local_storage_proto __weak; +const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak; const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) { diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index d8b7b110a1c5..01878db15eaf 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -12,6 +12,8 @@ #include <linux/filter.h> #include <linux/ctype.h> #include <linux/jiffies.h> +#include <linux/pid_namespace.h> +#include <linux/proc_ns.h> #include "../../lib/kstrtox.h" @@ -499,3 +501,46 @@ const struct bpf_func_proto bpf_strtoul_proto = { .arg4_type = ARG_PTR_TO_LONG, }; #endif + +BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino, + struct bpf_pidns_info *, nsdata, u32, size) +{ + struct task_struct *task = current; + struct pid_namespace *pidns; + int err = -EINVAL; + + if (unlikely(size != sizeof(struct bpf_pidns_info))) + goto clear; + + if (unlikely((u64)(dev_t)dev != dev)) + goto clear; + + if (unlikely(!task)) + goto clear; + + pidns = task_active_pid_ns(task); + if (unlikely(!pidns)) { + err = -ENOENT; + goto clear; + } + + if (!ns_match(&pidns->ns, (dev_t)dev, ino)) + goto clear; + + nsdata->pid = task_pid_nr_ns(task, pidns); + nsdata->tgid = task_tgid_nr_ns(task, pidns); + return 0; +clear: + memset((void *)nsdata, 0, (size_t) size); + return err; +} + +const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = { + .func = bpf_get_ns_current_pid_tgid, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_ANYTHING, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_PTR_TO_UNINIT_MEM, + .arg4_type = ARG_CONST_SIZE, +}; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 6a490d8ce9de..b5071c7e93ca 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -843,6 +843,8 @@ tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_send_signal_thread_proto; case BPF_FUNC_perf_event_read_value: return &bpf_perf_event_read_value_proto; + case BPF_FUNC_get_ns_current_pid_tgid: + return &bpf_get_ns_current_pid_tgid_proto; default: return NULL; } diff --git a/scripts/bpf_helpers_doc.py b/scripts/bpf_helpers_doc.py index cebed6fb5bbb..c1e2b5410faa 100755 --- a/scripts/bpf_helpers_doc.py +++ b/scripts/bpf_helpers_doc.py @@ -435,6 +435,7 @@ class PrinterHelpers(Printer): 'struct bpf_fib_lookup', 'struct bpf_perf_event_data', 'struct bpf_perf_event_value', + 'struct bpf_pidns_info', 'struct bpf_sock', 'struct bpf_sock_addr', 'struct bpf_sock_ops', diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 40b2d9476268..15b239da775b 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2914,6 +2914,19 @@ union bpf_attr { * of sizeof(struct perf_branch_entry). * * **-ENOENT** if architecture does not support branch records. + * + * int bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size) + * Description + * Returns 0 on success, values for *pid* and *tgid* as seen from the current + * *namespace* will be returned in *nsdata*. + * + * On failure, the returned value is one of the following: + * + * **-EINVAL** if dev and inum supplied don't match dev_t and inode number + * with nsfs of current task, or if dev conversion to dev_t lost high bits. + * + * **-ENOENT** if pidns does not exists for the current task. + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3035,7 +3048,8 @@ union bpf_attr { FN(tcp_send_ack), \ FN(send_signal_thread), \ FN(jiffies64), \ - FN(read_branch_records), + FN(read_branch_records), \ + FN(get_ns_current_pid_tgid), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -3829,4 +3843,8 @@ struct bpf_sockopt { __s32 retval; }; +struct bpf_pidns_info { + __u32 pid; + __u32 tgid; +}; #endif /* _UAPI__LINUX_BPF_H__ */ diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore index ec464859c6b6..2198cd876675 100644 --- a/tools/testing/selftests/bpf/.gitignore +++ b/tools/testing/selftests/bpf/.gitignore @@ -31,6 +31,7 @@ test_tcp_check_syncookie_user test_sysctl test_hashmap test_btf_dump +test_current_pid_tgid_new_ns xdping test_cpp *.skel.h diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index ee4ad34adb4a..da4389dde9f7 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -32,7 +32,8 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test test_sock test_btf test_sockmap get_cgroup_id_user test_socket_cookie \ test_cgroup_storage \ test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \ - test_progs-no_alu32 + test_progs-no_alu32 \ + test_current_pid_tgid_new_ns # Also test bpf-gcc, if present ifneq ($(BPF_GCC),) diff --git a/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c b/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c new file mode 100644 index 000000000000..542240e16564 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Carlos Neira cneirabustos@gmail.com */ +#include <test_progs.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> +#include <sys/syscall.h> + +struct bss { + __u64 dev; + __u64 ino; + __u64 pid_tgid; + __u64 user_pid_tgid; +}; + +void test_ns_current_pid_tgid(void) +{ + const char *probe_name = "raw_tracepoint/sys_enter"; + const char *file = "test_ns_current_pid_tgid.o"; + int err, key = 0, duration = 0; + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_map *bss_map; + struct bpf_object *obj; + struct bss bss; + struct stat st; + __u64 id; + + obj = bpf_object__open_file(file, NULL); + if (CHECK(IS_ERR(obj), "obj_open", "err %ld\n", PTR_ERR(obj))) + return; + + err = bpf_object__load(obj); + if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) + goto cleanup; + + bss_map = bpf_object__find_map_by_name(obj, "test_ns_.bss"); + if (CHECK(!bss_map, "find_bss_map", "failed\n")) + goto cleanup; + + prog = bpf_object__find_program_by_title(obj, probe_name); + if (CHECK(!prog, "find_prog", "prog '%s' not found\n", + probe_name)) + goto cleanup; + + memset(&bss, 0, sizeof(bss)); + pid_t tid = syscall(SYS_gettid); + pid_t pid = getpid(); + + id = (__u64) tid << 32 | pid; + bss.user_pid_tgid = id; + + if (CHECK_FAIL(stat("/proc/self/ns/pid", &st))) { + perror("Failed to stat /proc/self/ns/pid"); + goto cleanup; + } + + bss.dev = st.st_dev; + bss.ino = st.st_ino; + + err = bpf_map_update_elem(bpf_map__fd(bss_map), &key, &bss, 0); + if (CHECK(err, "setting_bss", "failed to set bss : %d\n", err)) + goto cleanup; + + link = bpf_program__attach_raw_tracepoint(prog, "sys_enter"); + if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n", + PTR_ERR(link))) { + link = NULL; + goto cleanup; + } + + /* trigger some syscalls */ + usleep(1); + + err = bpf_map_lookup_elem(bpf_map__fd(bss_map), &key, &bss); + if (CHECK(err, "set_bss", "failed to get bss : %d\n", err)) + goto cleanup; + + if (CHECK(id != bss.pid_tgid, "Compare user pid/tgid vs. bpf pid/tgid", + "User pid/tgid %llu BPF pid/tgid %llu\n", id, bss.pid_tgid)) + goto cleanup; +cleanup: + if (!link) { + bpf_link__destroy(link); + link = NULL; + } + bpf_object__close(obj); +} diff --git a/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c b/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c new file mode 100644 index 000000000000..1dca70a6de2f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Carlos Neira cneirabustos@gmail.com */ + +#include <linux/bpf.h> +#include <stdint.h> +#include <bpf/bpf_helpers.h> + +static volatile struct { + __u64 dev; + __u64 ino; + __u64 pid_tgid; + __u64 user_pid_tgid; +} res; + +SEC("raw_tracepoint/sys_enter") +int trace(void *ctx) +{ + __u64 ns_pid_tgid, expected_pid; + struct bpf_pidns_info nsdata; + __u32 key = 0; + + if (bpf_get_ns_current_pid_tgid(res.dev, res.ino, &nsdata, + sizeof(struct bpf_pidns_info))) + return 0; + + ns_pid_tgid = (__u64)nsdata.tgid << 32 | nsdata.pid; + expected_pid = res.user_pid_tgid; + + if (expected_pid != ns_pid_tgid) + return 0; + + res.pid_tgid = ns_pid_tgid; + + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_current_pid_tgid_new_ns.c b/tools/testing/selftests/bpf/test_current_pid_tgid_new_ns.c new file mode 100644 index 000000000000..ed253f252cd0 --- /dev/null +++ b/tools/testing/selftests/bpf/test_current_pid_tgid_new_ns.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Carlos Neira cneirabustos@gmail.com */ +#define _GNU_SOURCE +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> +#include <sys/syscall.h> +#include <sched.h> +#include <sys/wait.h> +#include <sys/mount.h> +#include "test_progs.h" + +#define CHECK_NEWNS(condition, tag, format...) ({ \ + int __ret = !!(condition); \ + if (__ret) { \ + printf("%s:FAIL:%s ", __func__, tag); \ + printf(format); \ + } else { \ + printf("%s:PASS:%s\n", __func__, tag); \ + } \ + __ret; \ +}) + +struct bss { + __u64 dev; + __u64 ino; + __u64 pid_tgid; + __u64 user_pid_tgid; +}; + +int main(int argc, char **argv) +{ + pid_t pid; + int exit_code = 1; + struct stat st; + + printf("Testing bpf_get_ns_current_pid_tgid helper in new ns\n"); + + if (stat("/proc/self/ns/pid", &st)) { + perror("stat failed on /proc/self/ns/pid ns\n"); + printf("%s:FAILED\n", argv[0]); + return exit_code; + } + + if (CHECK_NEWNS(unshare(CLONE_NEWPID | CLONE_NEWNS), + "unshare CLONE_NEWPID | CLONE_NEWNS", "error errno=%d\n", errno)) + return exit_code; + + pid = fork(); + if (pid == -1) { + perror("Fork() failed\n"); + printf("%s:FAILED\n", argv[0]); + return exit_code; + } + + if (pid > 0) { + int status; + + usleep(5); + waitpid(pid, &status, 0); + return 0; + } else { + + pid = fork(); + if (pid == -1) { + perror("Fork() failed\n"); + printf("%s:FAILED\n", argv[0]); + return exit_code; + } + + if (pid > 0) { + int status; + waitpid(pid, &status, 0); + return 0; + } else { + if (CHECK_NEWNS(mount("none", "/proc", NULL, MS_PRIVATE|MS_REC, NULL), + "Unmounting proc", "Cannot umount proc! errno=%d\n", errno)) + return exit_code; + + if (CHECK_NEWNS(mount("proc", "/proc", "proc", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL), + "Mounting proc", "Cannot mount proc! errno=%d\n", errno)) + return exit_code; + + const char *probe_name = "raw_tracepoint/sys_enter"; + const char *file = "test_ns_current_pid_tgid.o"; + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_map *bss_map; + struct bpf_object *obj; + int exit_code = 1; + int err, key = 0; + struct bss bss; + struct stat st; + __u64 id; + + obj = bpf_object__open_file(file, NULL); + if (CHECK_NEWNS(IS_ERR(obj), "obj_open", "err %ld\n", PTR_ERR(obj))) + return exit_code; + + err = bpf_object__load(obj); + if (CHECK_NEWNS(err, "obj_load", "err %d errno %d\n", err, errno)) + goto cleanup; + + bss_map = bpf_object__find_map_by_name(obj, "test_ns_.bss"); + if (CHECK_NEWNS(!bss_map, "find_bss_map", "failed\n")) + goto cleanup; + + prog = bpf_object__find_program_by_title(obj, probe_name); + if (CHECK_NEWNS(!prog, "find_prog", "prog '%s' not found\n", + probe_name)) + goto cleanup; + + memset(&bss, 0, sizeof(bss)); + pid_t tid = syscall(SYS_gettid); + pid_t pid = getpid(); + + id = (__u64) tid << 32 | pid; + bss.user_pid_tgid = id; + + if (CHECK_NEWNS(stat("/proc/self/ns/pid", &st), + "stat new ns", "Failed to stat /proc/self/ns/pid errno=%d\n", errno)) + goto cleanup; + + bss.dev = st.st_dev; + bss.ino = st.st_ino; + + err = bpf_map_update_elem(bpf_map__fd(bss_map), &key, &bss, 0); + if (CHECK_NEWNS(err, "setting_bss", "failed to set bss : %d\n", err)) + goto cleanup; + + link = bpf_program__attach_raw_tracepoint(prog, "sys_enter"); + if (CHECK_NEWNS(IS_ERR(link), "attach_raw_tp", "err %ld\n", + PTR_ERR(link))) { + link = NULL; + goto cleanup; + } + + /* trigger some syscalls */ + usleep(1); + + err = bpf_map_lookup_elem(bpf_map__fd(bss_map), &key, &bss); + if (CHECK_NEWNS(err, "set_bss", "failed to get bss : %d\n", err)) + goto cleanup; + + if (CHECK_NEWNS(id != bss.pid_tgid, "Compare user pid/tgid vs. bpf pid/tgid", + "User pid/tgid %llu BPF pid/tgid %llu\n", id, bss.pid_tgid)) + goto cleanup; + + exit_code = 0; + printf("%s:PASS\n", argv[0]); +cleanup: + if (!link) { + bpf_link__destroy(link); + link = NULL; + } + bpf_object__close(obj); + } + } +} |