^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Permission to use, copy, modify, and distribute this software for any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * purpose with or without fee is hereby granted, provided that the above
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * copyright notice and this permission notice appear in all copies.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) // Test
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) // 1) read of every file in /proc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) // 2) readlink of every symlink in /proc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) // 3) recursively (1) + (2) for every directory in /proc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) // 4) write to /proc/*/clear_refs and /proc/*/task/*/clear_refs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) // 5) write to /proc/sysrq-trigger
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #undef NDEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <assert.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <sys/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <dirent.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <stdbool.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <stdlib.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <stdio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <sys/stat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <sys/vfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <fcntl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include "proc.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) static void f_reg(DIR *d, const char *filename)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) char buf[4096];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) int fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) ssize_t rv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) /* read from /proc/kmsg can block */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) fd = openat(dirfd(d), filename, O_RDONLY|O_NONBLOCK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) if (fd == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) rv = read(fd, buf, sizeof(buf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) assert((0 <= rv && rv <= sizeof(buf)) || rv == -1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) close(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) static void f_reg_write(DIR *d, const char *filename, const char *buf, size_t len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) int fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) ssize_t rv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) fd = openat(dirfd(d), filename, O_WRONLY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) if (fd == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) rv = write(fd, buf, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) assert((0 <= rv && rv <= len) || rv == -1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) close(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) static void f_lnk(DIR *d, const char *filename)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) char buf[4096];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) ssize_t rv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) rv = readlinkat(dirfd(d), filename, buf, sizeof(buf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) assert((0 <= rv && rv <= sizeof(buf)) || rv == -1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) static void f(DIR *d, unsigned int level)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) struct dirent *de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) de = xreaddir(d);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) assert(de->d_type == DT_DIR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) assert(streq(de->d_name, "."));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) de = xreaddir(d);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) assert(de->d_type == DT_DIR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) assert(streq(de->d_name, ".."));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) while ((de = xreaddir(d))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) assert(!streq(de->d_name, "."));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) assert(!streq(de->d_name, ".."));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) switch (de->d_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) DIR *dd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) int fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) case DT_REG:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) if (level == 0 && streq(de->d_name, "sysrq-trigger")) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) f_reg_write(d, de->d_name, "h", 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) } else if (level == 1 && streq(de->d_name, "clear_refs")) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) f_reg_write(d, de->d_name, "1", 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) } else if (level == 3 && streq(de->d_name, "clear_refs")) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) f_reg_write(d, de->d_name, "1", 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) f_reg(d, de->d_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) case DT_DIR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) fd = openat(dirfd(d), de->d_name, O_DIRECTORY|O_RDONLY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) if (fd == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) dd = fdopendir(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (!dd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) f(dd, level + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) closedir(dd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) case DT_LNK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) f_lnk(d, de->d_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) assert(0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) int main(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) DIR *d;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) struct statfs sfs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) d = opendir("/proc");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) if (!d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) return 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) /* Ensure /proc is proc. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) if (fstatfs(dirfd(d), &sfs) == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) if (sfs.f_type != 0x9fa0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) fprintf(stderr, "error: unexpected f_type %lx\n", (long)sfs.f_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) return 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) f(d, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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