cregit-Linux how code gets into the kernel

Release 4.16 usr/gen_init_cpio.c

Directory: usr
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <limits.h>

/*
 * Original work by Jeff Garzik
 *
 * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
 * Hard link support by Luciano Rocha
 */


#define xstr(s) #s

#define str(s) xstr(s)


static unsigned int offset;

static unsigned int ino = 721;

static time_t default_mtime;


struct file_handler {
	
const char *type;
	
int (*handler)(const char *line);
};


static void push_string(const char *name) { unsigned int name_len = strlen(name) + 1; fputs(name, stdout); putchar(0); offset += name_len; }

Contributors

PersonTokensPropCommitsCommitProp
Greg Kroah-Hartman38100.00%1100.00%
Total38100.00%1100.00%


static void push_pad (void) { while (offset & 3) { putchar(0); offset++; } }

Contributors

PersonTokensPropCommitsCommitProp
Greg Kroah-Hartman24100.00%1100.00%
Total24100.00%1100.00%


static void push_rest(const char *name) { unsigned int name_len = strlen(name) + 1; unsigned int tmp_ofs; fputs(name, stdout); putchar(0); offset += name_len; tmp_ofs = name_len + 110; while (tmp_ofs & 3) { putchar(0); offset++; tmp_ofs++; } }

Contributors

PersonTokensPropCommitsCommitProp
Jeff Garzik67100.00%1100.00%
Total67100.00%1100.00%


static void push_hdr(const char *s) { fputs(s, stdout); offset += 110; }

Contributors

PersonTokensPropCommitsCommitProp
Jeff Garzik22100.00%1100.00%
Total22100.00%1100.00%


static void cpio_trailer(void) { char s[256]; const char name[] = "TRAILER!!!"; sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX" "%08X%08X%08X%08X%08X%08X%08X", "070701", /* magic */ 0, /* ino */ 0, /* mode */ (long) 0, /* uid */ (long) 0, /* gid */ 1, /* nlink */ (long) 0, /* mtime */ 0, /* filesize */ 0, /* major */ 0, /* minor */ 0, /* rmajor */ 0, /* rminor */ (unsigned)strlen(name)+1, /* namesize */ 0); /* chksum */ push_hdr(s); push_rest(name); while (offset % 512) { putchar(0); offset++; } }

Contributors

PersonTokensPropCommitsCommitProp
Jeff Garzik10995.61%133.33%
Andrew Morton43.51%133.33%
Randy Dunlap10.88%133.33%
Total114100.00%3100.00%


static int cpio_mkslink(const char *name, const char *target, unsigned int mode, uid_t uid, gid_t gid) { char s[256]; if (name[0] == '/') name++; sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX" "%08X%08X%08X%08X%08X%08X%08X", "070701", /* magic */ ino++, /* ino */ S_IFLNK | mode, /* mode */ (long) uid, /* uid */ (long) gid, /* gid */ 1, /* nlink */ (long) default_mtime, /* mtime */ (unsigned)strlen(target)+1, /* filesize */ 3, /* major */ 1, /* minor */ 0, /* rmajor */ 0, /* rminor */ (unsigned)strlen(name) + 1,/* namesize */ 0); /* chksum */ push_hdr(s); push_string(name); push_pad(); push_string(target); push_pad(); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh7954.11%233.33%
Jeff Garzik5336.30%116.67%
Thomas Chou128.22%116.67%
Andrew Morton10.68%116.67%
Michal Marek10.68%116.67%
Total146100.00%6100.00%


static int cpio_mkslink_line(const char *line) { char name[PATH_MAX + 1]; char target[PATH_MAX + 1]; unsigned int mode; int uid; int gid; int rc = -1; if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) { fprintf(stderr, "Unrecognized dir format '%s'", line); goto fail; } rc = cpio_mkslink(name, target, mode, uid, gid); fail: return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh111100.00%1100.00%
Total111100.00%1100.00%


static int cpio_mkgeneric(const char *name, unsigned int mode, uid_t uid, gid_t gid) { char s[256]; if (name[0] == '/') name++; sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX" "%08X%08X%08X%08X%08X%08X%08X", "070701", /* magic */ ino++, /* ino */ mode, /* mode */ (long) uid, /* uid */ (long) gid, /* gid */ 2, /* nlink */ (long) default_mtime, /* mtime */ 0, /* filesize */ 3, /* major */ 1, /* minor */ 0, /* rmajor */ 0, /* rminor */ (unsigned)strlen(name) + 1,/* namesize */ 0); /* chksum */ push_hdr(s); push_rest(name); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh5848.33%233.33%
Jeff Garzik4638.33%116.67%
Thomas Chou1210.00%116.67%
Andrew Morton32.50%116.67%
Michal Marek10.83%116.67%
Total120100.00%6100.00%

enum generic_types { GT_DIR, GT_PIPE, GT_SOCK }; struct generic_type { const char *type; mode_t mode; }; static struct generic_type generic_type_table[] = { [GT_DIR] = { .type = "dir", .mode = S_IFDIR }, [GT_PIPE] = { .type = "pipe", .mode = S_IFIFO }, [GT_SOCK] = { .type = "sock", .mode = S_IFSOCK } };
static int cpio_mkgeneric_line(const char *line, enum generic_types gt) { char name[PATH_MAX + 1]; unsigned int mode; int uid; int gid; int rc = -1; if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) { fprintf(stderr, "Unrecognized %s format '%s'", line, generic_type_table[gt].type); goto fail; } mode |= generic_type_table[gt].mode; rc = cpio_mkgeneric(name, mode, uid, gid); fail: return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh11399.12%266.67%
Jeff Garzik10.88%133.33%
Total114100.00%3100.00%


static int cpio_mkdir_line(const char *line) { return cpio_mkgeneric_line(line, GT_DIR); }

Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh19100.00%1100.00%
Total19100.00%1100.00%


static int cpio_mkpipe_line(const char *line) { return cpio_mkgeneric_line(line, GT_PIPE); }

Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh19100.00%1100.00%
Total19100.00%1100.00%


static int cpio_mksock_line(const char *line) { return cpio_mkgeneric_line(line, GT_SOCK); }

Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh19100.00%1100.00%
Total19100.00%1100.00%


static int cpio_mknod(const char *name, unsigned int mode, uid_t uid, gid_t gid, char dev_type, unsigned int maj, unsigned int min) { char s[256]; if (dev_type == 'b') mode |= S_IFBLK; else mode |= S_IFCHR; if (name[0] == '/') name++; sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX" "%08X%08X%08X%08X%08X%08X%08X", "070701", /* magic */ ino++, /* ino */ mode, /* mode */ (long) uid, /* uid */ (long) gid, /* gid */ 1, /* nlink */ (long) default_mtime, /* mtime */ 0, /* filesize */ 3, /* major */ 1, /* minor */ maj, /* rmajor */ min, /* rminor */ (unsigned)strlen(name) + 1,/* namesize */ 0); /* chksum */ push_hdr(s); push_rest(name); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jeff Garzik12283.56%120.00%
Thomas Chou128.22%120.00%
Thayne Harbaugh74.79%120.00%
Andrew Morton42.74%120.00%
Michal Marek10.68%120.00%
Total146100.00%5100.00%


static int cpio_mknod_line(const char *line) { char name[PATH_MAX + 1]; unsigned int mode; int uid; int gid; char dev_type; unsigned int maj; unsigned int min; int rc = -1; if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u", name, &mode, &uid, &gid, &dev_type, &maj, &min)) { fprintf(stderr, "Unrecognized nod format '%s'", line); goto fail; } rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min); fail: return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh11999.17%150.00%
Jeff Garzik10.83%150.00%
Total120100.00%2100.00%


static int cpio_mkfile(const char *name, const char *location, unsigned int mode, uid_t uid, gid_t gid, unsigned int nlinks) { char s[256]; char *filebuf = NULL; struct stat buf; long size; int file = -1; int retval; int rc = -1; int namesize; unsigned int i; mode |= S_IFREG; file = open (location, O_RDONLY); if (file < 0) { fprintf (stderr, "File %s could not be opened for reading\n", location); goto error; } retval = fstat(file, &buf); if (retval) { fprintf(stderr, "File %s could not be stat()'ed\n", location); goto error; } filebuf = malloc(buf.st_size); if (!filebuf) { fprintf (stderr, "out of memory\n"); goto error; } retval = read (file, filebuf, buf.st_size); if (retval < 0) { fprintf (stderr, "Can not read %s file\n", location); goto error; } size = 0; for (i = 1; i <= nlinks; i++) { /* data goes on last link */ if (i == nlinks) size = buf.st_size; if (name[0] == '/') name++; namesize = strlen(name) + 1; sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX" "%08lX%08X%08X%08X%08X%08X%08X", "070701", /* magic */ ino, /* ino */ mode, /* mode */ (long) uid, /* uid */ (long) gid, /* gid */ nlinks, /* nlink */ (long) buf.st_mtime, /* mtime */ size, /* filesize */ 3, /* major */ 1, /* minor */ 0, /* rmajor */ 0, /* rminor */ namesize, /* namesize */ 0); /* chksum */ push_hdr(s); push_string(name); push_pad(); if (size) { if (fwrite(filebuf, size, 1, stdout) != 1) { fprintf(stderr, "writing filebuf failed\n"); goto error; } offset += size; push_pad(); } name += namesize; } ino++; rc = 0; error: if (filebuf) free(filebuf); if (file >= 0) close(file); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Greg Kroah-Hartman23058.38%111.11%
Luciano Rocha7318.53%111.11%
Thayne Harbaugh399.90%111.11%
Mike Frysinger164.06%111.11%
Jesper Juhl143.55%111.11%
Thomas Chou123.05%111.11%
Jeff Garzik61.52%111.11%
Andrew Morton30.76%111.11%
Kees Cook10.25%111.11%
Total394100.00%9100.00%


static char *cpio_replace_env(char *new_location) { char expanded[PATH_MAX + 1]; char *start, *end, *var; while ((start = strstr(new_location, "${")) && (end = strchr(start + 2, '}'))) { *start = *end = 0; var = getenv(start + 2); snprintf(expanded, sizeof expanded, "%s%s%s", new_location, var ? var : "", end + 1); strcpy(new_location, expanded); } return new_location; }

Contributors

PersonTokensPropCommitsCommitProp
Sally, Gene7873.58%150.00%
Michal Nazarewicz2826.42%150.00%
Total106100.00%2100.00%


static int cpio_mkfile_line(const char *line) { char name[PATH_MAX + 1]; char *dname = NULL; /* malloc'ed buffer for hard links */ char location[PATH_MAX + 1]; unsigned int mode; int uid; int gid; int nlinks = 1; int end = 0, dname_len = 0; int rc = -1; if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d %n", name, location, &mode, &uid, &gid, &end)) { fprintf(stderr, "Unrecognized file format '%s'", line); goto fail; } if (end && isgraph(line[end])) { int len; int nend; dname = malloc(strlen(line)); if (!dname) { fprintf (stderr, "out of memory (%d)\n", dname_len); goto fail; } dname_len = strlen(name) + 1; memcpy(dname, name, dname_len); do { nend = 0; if (sscanf(line + end, "%" str(PATH_MAX) "s %n", name, &nend) < 1) break; len = strlen(name) + 1; memcpy(dname + dname_len, name, len); dname_len += len; nlinks++; end += nend; } while (isgraph(line[end])); } else { dname = name; } rc = cpio_mkfile(dname, cpio_replace_env(location), mode, uid, gid, nlinks); fail: if (dname_len) free(dname); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Luciano Rocha18562.50%125.00%
Thayne Harbaugh10334.80%125.00%
Greg Kroah-Hartman51.69%125.00%
Sally, Gene31.01%125.00%
Total296100.00%4100.00%


static void usage(const char *prog) { fprintf(stderr, "Usage:\n" "\t%s [-t <timestamp>] <cpio_list>\n" "\n" "<cpio_list> is a file containing newline separated entries that\n" "describe the files to be included in the initramfs archive:\n" "\n" "# a comment\n" "file <name> <location> <mode> <uid> <gid> [<hard links>]\n" "dir <name> <mode> <uid> <gid>\n" "nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n" "slink <name> <target> <mode> <uid> <gid>\n" "pipe <name> <mode> <uid> <gid>\n" "sock <name> <mode> <uid> <gid>\n" "\n" "<name> name of the file/dir/nod/etc in the archive\n" "<location> location of the file in the current filesystem\n" " expands shell variables quoted with ${}\n" "<target> link target\n" "<mode> mode/permissions of the file\n" "<uid> user id (0=root)\n" "<gid> group id (0=root)\n" "<dev_type> device type (b=block, c=character)\n" "<maj> major number of nod\n" "<min> minor number of nod\n" "<hard links> space separated list of other links to file\n" "\n" "example:\n" "# A simple initramfs\n" "dir /dev 0755 0 0\n" "nod /dev/console 0600 0 0 c 5 1\n" "dir /root 0700 0 0\n" "dir /sbin 0755 0 0\n" "file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n" "\n" "<timestamp> is time in seconds since Epoch that will be used\n" "as mtime for symlinks, special files and directories. The default\n" "is to use the current time for these entries.\n", prog); }

Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh3867.86%233.33%
Luciano Rocha1119.64%116.67%
Michal Marek58.93%116.67%
Trevor Keith11.79%116.67%
Sally, Gene11.79%116.67%
Total56100.00%6100.00%

struct file_handler file_handler_table[] = { { .type = "file", .handler = cpio_mkfile_line, }, { .type = "nod", .handler = cpio_mknod_line, }, { .type = "dir", .handler = cpio_mkdir_line, }, { .type = "slink", .handler = cpio_mkslink_line, }, { .type = "pipe", .handler = cpio_mkpipe_line, }, { .type = "sock", .handler = cpio_mksock_line, }, { .type = NULL, .handler = NULL, } }; #define LINE_SIZE (2 * PATH_MAX + 50)
int main (int argc, char *argv[]) { FILE *cpio_list; char line[LINE_SIZE]; char *args, *type; int ec = 0; int line_nr = 0; const char *filename; default_mtime = time(NULL); while (1) { int opt = getopt(argc, argv, "t:h"); char *invalid; if (opt == -1) break; switch (opt) { case 't': default_mtime = strtol(optarg, &invalid, 10); if (!*optarg || *invalid) { fprintf(stderr, "Invalid timestamp: %s\n", optarg); usage(argv[0]); exit(1); } break; case 'h': case '?': usage(argv[0]); exit(opt == 'h' ? 0 : 1); } } if (argc - optind != 1) { usage(argv[0]); exit(1); } filename = argv[optind]; if (!strcmp(filename, "-")) cpio_list = stdin; else if (!(cpio_list = fopen(filename, "r"))) { fprintf(stderr, "ERROR: unable to open '%s': %s\n\n", filename, strerror(errno)); usage(argv[0]); exit(1); } while (fgets(line, LINE_SIZE, cpio_list)) { int type_idx; size_t slen = strlen(line); line_nr++; if ('#' == *line) { /* comment - skip to next line */ continue; } if (! (type = strtok(line, " \t"))) { fprintf(stderr, "ERROR: incorrect format, could not locate file type line %d: '%s'\n", line_nr, line); ec = -1; break; } if ('\n' == *type) { /* a blank line */ continue; } if (slen == strlen(type)) { /* must be an empty line */ continue; } if (! (args = strtok(NULL, "\n"))) { fprintf(stderr, "ERROR: incorrect format, newline required line %d: '%s'\n", line_nr, line); ec = -1; } for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) { int rc; if (! strcmp(line, file_handler_table[type_idx].type)) { if ((rc = file_handler_table[type_idx].handler(args))) { ec = rc; fprintf(stderr, " line %d\n", line_nr); } break; } } if (NULL == file_handler_table[type_idx].type) { fprintf(stderr, "unknown file type line %d: '%s'\n", line_nr, line); } } if (ec == 0) cpio_trailer(); exit(ec); }

Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh28358.35%233.33%
Michal Marek13527.84%116.67%
Jeff Garzik438.87%116.67%
Mike Frysinger173.51%116.67%
Jesper Juhl71.44%116.67%
Total485100.00%6100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Thayne Harbaugh122645.80%210.00%
Jeff Garzik50318.79%210.00%
Greg Kroah-Hartman30111.24%210.00%
Luciano Rocha27010.09%15.00%
Michal Marek1475.49%15.00%
Sally, Gene823.06%15.00%
Thomas Chou481.79%15.00%
Mike Frysinger331.23%210.00%
Michal Nazarewicz281.05%15.00%
Jesper Juhl210.78%210.00%
Andrew Morton150.56%210.00%
Kees Cook10.04%15.00%
Randy Dunlap10.04%15.00%
Trevor Keith10.04%15.00%
Total2677100.00%20100.00%
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