diff options
Diffstat (limited to 'usr/gen_init_cpio.c')
| -rw-r--r-- | usr/gen_init_cpio.c | 269 |
1 files changed, 181 insertions, 88 deletions
diff --git a/usr/gen_init_cpio.c b/usr/gen_init_cpio.c index 61230532fef1..b7296edc6626 100644 --- a/usr/gen_init_cpio.c +++ b/usr/gen_init_cpio.c @@ -1,4 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <stdint.h> @@ -23,63 +24,72 @@ #define xstr(s) #s #define str(s) xstr(s) #define MIN(a, b) ((a) < (b) ? (a) : (b)) +#define CPIO_HDR_LEN 110 +#define CPIO_TRAILER "TRAILER!!!" +#define padlen(_off, _align) (((_align) - ((_off) & ((_align) - 1))) % (_align)) +/* zero-padding the filename field for data alignment is limited by PATH_MAX */ +static char padding[PATH_MAX]; static unsigned int offset; static unsigned int ino = 721; static time_t default_mtime; +static bool do_file_mtime; static bool do_csum = false; +static int outfd = STDOUT_FILENO; +static unsigned int dalign; struct file_handler { const char *type; int (*handler)(const char *line); }; -static void push_string(const char *name) +static int push_buf(const char *name, size_t name_len) { - unsigned int name_len = strlen(name) + 1; + ssize_t len; + + len = write(outfd, name, name_len); + if (len != name_len) + return -1; - fputs(name, stdout); - putchar(0); offset += name_len; + return 0; } -static void push_pad (void) +static int push_pad(size_t padlen) { - while (offset & 3) { - putchar(0); - offset++; - } -} + ssize_t len = 0; -static void push_rest(const char *name) -{ - unsigned int name_len = strlen(name) + 1; - unsigned int tmp_ofs; + if (!padlen) + return 0; - fputs(name, stdout); - putchar(0); - offset += name_len; + if (padlen < sizeof(padding)) + len = write(outfd, padding, padlen); + if (len != padlen) + return -1; - tmp_ofs = name_len + 110; - while (tmp_ofs & 3) { - putchar(0); - offset++; - tmp_ofs++; - } + offset += padlen; + return 0; } -static void push_hdr(const char *s) +static int push_rest(const char *name, size_t name_len) { - fputs(s, stdout); - offset += 110; + ssize_t len; + + len = write(outfd, name, name_len); + if (len != name_len) + return -1; + + offset += name_len; + + return push_pad(padlen(name_len + CPIO_HDR_LEN, 4)); } -static void cpio_trailer(void) +static int cpio_trailer(void) { - char s[256]; - const char name[] = "TRAILER!!!"; + int len; + unsigned int namesize = sizeof(CPIO_TRAILER); - sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX" + len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX" "%08X%08X%08X%08X%08X%08X%08X", do_csum ? "070702" : "070701", /* magic */ 0, /* ino */ @@ -93,25 +103,32 @@ static void cpio_trailer(void) 0, /* minor */ 0, /* rmajor */ 0, /* rminor */ - (unsigned)strlen(name)+1, /* namesize */ + namesize, /* namesize */ 0); /* chksum */ - push_hdr(s); - push_rest(name); + offset += len; - while (offset % 512) { - putchar(0); - offset++; - } + if (len != CPIO_HDR_LEN || + push_rest(CPIO_TRAILER, namesize) < 0 || + push_pad(padlen(offset, 512)) < 0) + return -1; + + if (fsync(outfd) < 0 && errno != EINVAL) + return -1; + + return 0; } static int cpio_mkslink(const char *name, const char *target, unsigned int mode, uid_t uid, gid_t gid) { - char s[256]; + int len; + unsigned int namesize, targetsize = strlen(target) + 1; if (name[0] == '/') name++; - sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX" + namesize = strlen(name) + 1; + + len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX" "%08X%08X%08X%08X%08X%08X%08X", do_csum ? "070702" : "070701", /* magic */ ino++, /* ino */ @@ -120,19 +137,24 @@ static int cpio_mkslink(const char *name, const char *target, (long) gid, /* gid */ 1, /* nlink */ (long) default_mtime, /* mtime */ - (unsigned)strlen(target)+1, /* filesize */ + targetsize, /* filesize */ 3, /* major */ 1, /* minor */ 0, /* rmajor */ 0, /* rminor */ - (unsigned)strlen(name) + 1,/* namesize */ + namesize, /* namesize */ 0); /* chksum */ - push_hdr(s); - push_string(name); - push_pad(); - push_string(target); - push_pad(); + offset += len; + + if (len != CPIO_HDR_LEN || + push_buf(name, namesize) < 0 || + push_pad(padlen(offset, 4)) < 0 || + push_buf(target, targetsize) < 0 || + push_pad(padlen(offset, 4)) < 0) + return -1; + return 0; + } static int cpio_mkslink_line(const char *line) @@ -156,11 +178,14 @@ static int cpio_mkslink_line(const char *line) static int cpio_mkgeneric(const char *name, unsigned int mode, uid_t uid, gid_t gid) { - char s[256]; + int len; + unsigned int namesize; if (name[0] == '/') name++; - sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX" + namesize = strlen(name) + 1; + + len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX" "%08X%08X%08X%08X%08X%08X%08X", do_csum ? "070702" : "070701", /* magic */ ino++, /* ino */ @@ -174,10 +199,14 @@ static int cpio_mkgeneric(const char *name, unsigned int mode, 1, /* minor */ 0, /* rmajor */ 0, /* rminor */ - (unsigned)strlen(name) + 1,/* namesize */ + namesize, /* namesize */ 0); /* chksum */ - push_hdr(s); - push_rest(name); + offset += len; + + if (len != CPIO_HDR_LEN || + push_rest(name, namesize) < 0) + return -1; + return 0; } @@ -245,7 +274,8 @@ 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]; + int len; + unsigned int namesize; if (dev_type == 'b') mode |= S_IFBLK; @@ -254,7 +284,9 @@ static int cpio_mknod(const char *name, unsigned int mode, if (name[0] == '/') name++; - sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX" + namesize = strlen(name) + 1; + + len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX" "%08X%08X%08X%08X%08X%08X%08X", do_csum ? "070702" : "070701", /* magic */ ino++, /* ino */ @@ -268,10 +300,14 @@ static int cpio_mknod(const char *name, unsigned int mode, 1, /* minor */ maj, /* rmajor */ min, /* rminor */ - (unsigned)strlen(name) + 1,/* namesize */ + namesize, /* namesize */ 0); /* chksum */ - push_hdr(s); - push_rest(name); + offset += len; + + if (len != CPIO_HDR_LEN || + push_rest(name, namesize) < 0) + return -1; + return 0; } @@ -323,15 +359,15 @@ 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]; struct stat buf; unsigned long size; - int file; - int retval; + int file, retval, len; int rc = -1; - int namesize; + time_t mtime; + int namesize, namepadlen; unsigned int i; uint32_t csum = 0; + ssize_t this_read; mode |= S_IFREG; @@ -347,16 +383,21 @@ static int cpio_mkfile(const char *name, const char *location, goto error; } - if (buf.st_mtime > 0xffffffff) { - fprintf(stderr, "%s: Timestamp exceeds maximum cpio timestamp, clipping.\n", - location); - buf.st_mtime = 0xffffffff; - } + if (do_file_mtime) { + mtime = default_mtime; + } else { + mtime = buf.st_mtime; + if (mtime > 0xffffffff) { + fprintf(stderr, "%s: Timestamp exceeds maximum cpio timestamp, clipping.\n", + location); + mtime = 0xffffffff; + } - if (buf.st_mtime < 0) { - fprintf(stderr, "%s: Timestamp negative, clipping.\n", - location); - buf.st_mtime = 0; + if (mtime < 0) { + fprintf(stderr, "%s: Timestamp negative, clipping.\n", + location); + mtime = 0; + } } if (buf.st_size > 0xffffffff) { @@ -371,15 +412,28 @@ static int cpio_mkfile(const char *name, const char *location, } size = 0; + namepadlen = 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" + + /* data goes on last link, after any alignment padding */ + if (i == nlinks) + size = buf.st_size; + + if (dalign && size > dalign) { + namepadlen = padlen(offset + CPIO_HDR_LEN + namesize, + dalign); + if (namesize + namepadlen > PATH_MAX) { + fprintf(stderr, + "%s: best-effort alignment %u missed\n", + name, dalign); + namepadlen = 0; + } + } + + len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX" "%08lX%08X%08X%08X%08X%08X%08X", do_csum ? "070702" : "070701", /* magic */ ino, /* ino */ @@ -387,21 +441,34 @@ static int cpio_mkfile(const char *name, const char *location, (long) uid, /* uid */ (long) gid, /* gid */ nlinks, /* nlink */ - (long) buf.st_mtime, /* mtime */ + (long) mtime, /* mtime */ size, /* filesize */ 3, /* major */ 1, /* minor */ 0, /* rmajor */ 0, /* rminor */ - namesize, /* namesize */ + namesize + namepadlen, /* namesize */ size ? csum : 0); /* chksum */ - push_hdr(s); - push_string(name); - push_pad(); + offset += len; + + if (len != CPIO_HDR_LEN || + push_buf(name, namesize) < 0 || + push_pad(namepadlen ? namepadlen : padlen(offset, 4)) < 0) + goto error; + + if (size) { + this_read = copy_file_range(file, NULL, outfd, NULL, size, 0); + if (this_read > 0) { + if (this_read > size) + goto error; + offset += this_read; + size -= this_read; + } + /* short or failed copy falls back to read/write... */ + } while (size) { unsigned char filebuf[65536]; - ssize_t this_read; size_t this_size = MIN(size, sizeof(filebuf)); this_read = read(file, filebuf, this_size); @@ -410,14 +477,15 @@ static int cpio_mkfile(const char *name, const char *location, goto error; } - if (fwrite(filebuf, this_read, 1, stdout) != 1) { + if (write(outfd, filebuf, this_read) != this_read) { fprintf(stderr, "writing filebuf failed\n"); goto error; } offset += this_read; size -= this_read; } - push_pad(); + if (push_pad(padlen(offset, 4)) < 0) + goto error; name += namesize; } @@ -502,7 +570,7 @@ static int cpio_mkfile_line(const char *line) static void usage(const char *prog) { fprintf(stderr, "Usage:\n" - "\t%s [-t <timestamp>] [-c] <cpio_list>\n" + "\t%s [-t <timestamp>] [-c] [-o <output_file>] [-a <data_align>] <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" @@ -536,9 +604,14 @@ static void usage(const char *prog) "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" - "-c: calculate and store 32-bit checksums for file data.\n", + "as mtime for symlinks, directories, regular and special files.\n" + "The default is to use the current time for all files, but\n" + "preserve modification time for regular files.\n" + "-c: calculate and store 32-bit checksums for file data.\n" + "<output_file>: write cpio to this file instead of stdout\n" + "<data_align>: attempt to align file data by zero-padding the\n" + "filename field up to data_align. Must be a multiple of 4.\n" + "Alignment is best-effort; PATH_MAX limits filename padding.\n", prog); } @@ -580,7 +653,7 @@ int main (int argc, char *argv[]) default_mtime = time(NULL); while (1) { - int opt = getopt(argc, argv, "t:ch"); + int opt = getopt(argc, argv, "t:cho:a:"); char *invalid; if (opt == -1) @@ -594,10 +667,30 @@ int main (int argc, char *argv[]) usage(argv[0]); exit(1); } + do_file_mtime = true; break; case 'c': do_csum = true; break; + case 'o': + outfd = open(optarg, + O_WRONLY | O_CREAT | O_LARGEFILE | O_TRUNC, + 0600); + if (outfd < 0) { + fprintf(stderr, "failed to open %s\n", optarg); + usage(argv[0]); + exit(1); + } + break; + case 'a': + dalign = strtoul(optarg, &invalid, 10); + if (!*optarg || *invalid || (dalign & 3)) { + fprintf(stderr, "Invalid data_align: %s\n", + optarg); + usage(argv[0]); + exit(1); + } + break; case 'h': case '?': usage(argv[0]); @@ -682,7 +775,7 @@ int main (int argc, char *argv[]) } } if (ec == 0) - cpio_trailer(); + ec = cpio_trailer(); exit(ec); } |