diff options
Diffstat (limited to 'extlinux')
| -rw-r--r-- | extlinux/Makefile | 8 | ||||
| -rw-r--r-- | extlinux/extlinux.c | 331 |
2 files changed, 260 insertions, 79 deletions
diff --git a/extlinux/Makefile b/extlinux/Makefile index d2ea6f9b..908d1ce5 100644 --- a/extlinux/Makefile +++ b/extlinux/Makefile @@ -8,16 +8,16 @@ LDHASH := $(call gcc_ok,-Wl$(comma)--hash-style=both,) CC = gcc OPTFLAGS = -g -Os -INCLUDES = -I. -I.. -I../libfat +INCLUDES = -I. -I.. -I../libinstaller CFLAGS = -W -Wall -Wno-sign-compare -D_FILE_OFFSET_BITS=64 $(OPTFLAGS) $(INCLUDES) -LDFLAGS = $(LDHASH) -s +LDFLAGS = $(LDHASH) # -s -SRCS = extlinux.c ../extlinux_bss_bin.c ../extlinux_sys_bin.c +SRCS = extlinux.c setadv.c extlinux_bss_bin.c extlinux_sys_bin.c OBJS = $(patsubst %.c,%.o,$(notdir $(SRCS))) .SUFFIXES: .c .o .i .s .S -VPATH = .:.. +VPATH = .:..:../libinstaller all: installer diff --git a/extlinux/extlinux.c b/extlinux/extlinux.c index a81dff7a..58261b44 100644 --- a/extlinux/extlinux.c +++ b/extlinux/extlinux.c @@ -43,6 +43,7 @@ typedef uint64_t u64; #include "ext2_fs.h" #include "../version.h" +#include "syslxint.h" #ifdef DEBUG # define dprintf printf @@ -59,10 +60,14 @@ struct my_options { unsigned int sectors; unsigned int heads; int raid_mode; + int reset_adv; + const char *set_once; } opt = { .sectors = 0, .heads = 0, .raid_mode = 0, + .reset_adv = 0, + .set_once = NULL, }; static void __attribute__((noreturn)) usage(int rv) @@ -75,6 +80,9 @@ static void __attribute__((noreturn)) usage(int rv) " --sectors=# -S Force the number of sectors per track\n" " --heads=# -H Force number of heads\n" " --raid -r Fall back to the next device on boot failure\n" + " --once=... -o Execute a command once upon boot\n" + " --clear-once -O Clear the boot-once command\n" + " --reset-adv Reset auxilliary data\n" "\n" " Note: geometry is determined at boot time for devices which\n" " are considered hard disks by the BIOS. Unfortunately, this is\n" @@ -88,19 +96,27 @@ static void __attribute__((noreturn)) usage(int rv) exit(rv); } +enum long_only_opt { + OPT_NONE, + OPT_RESET_ADV, +}; + static const struct option long_options[] = { - { "install", 0, NULL, 'i' }, - { "update", 0, NULL, 'U' }, - { "zipdrive", 0, NULL, 'z' }, - { "sectors", 1, NULL, 'S' }, - { "heads", 1, NULL, 'H' }, - { "raid-mode", 0, NULL, 'r' }, - { "version", 0, NULL, 'v' }, - { "help", 0, NULL, 'h' }, + { "install", 0, NULL, 'i' }, + { "update", 0, NULL, 'U' }, + { "zipdrive", 0, NULL, 'z' }, + { "sectors", 1, NULL, 'S' }, + { "heads", 1, NULL, 'H' }, + { "raid-mode", 0, NULL, 'r' }, + { "version", 0, NULL, 'v' }, + { "help", 0, NULL, 'h' }, + { "once", 1, NULL, 'o' }, + { "clear-once", 0, NULL, 'O' }, + { "reset-adv", 0, NULL, OPT_RESET_ADV }, { 0, 0, 0, 0 } }; -static const char short_options[] = "iUuzS:H:rvh"; +static const char short_options[] = "iUuzS:H:rvho:O"; #if defined(__linux__) && !defined(BLKGETSIZE64) /* This takes a u64, but the size field says size_t. Someone screwed big. */ @@ -158,66 +174,10 @@ enum bs_offsets { #define bsCode bs32Code /* The common safe choice */ #define bsCodeLen (bsSignature-bs32Code) -/* - * Access functions for littleendian numbers, possibly misaligned. - */ -static inline uint8_t get_8(const unsigned char *p) -{ - return *(const uint8_t *)p; -} - -static inline uint16_t get_16(const unsigned char *p) -{ -#if defined(__i386__) || defined(__x86_64__) - /* Littleendian and unaligned-capable */ - return *(const uint16_t *)p; -#else - return (uint16_t)p[0] + ((uint16_t)p[1] << 8); -#endif -} - -static inline uint32_t get_32(const unsigned char *p) -{ -#if defined(__i386__) || defined(__x86_64__) - /* Littleendian and unaligned-capable */ - return *(const uint32_t *)p; -#else - return (uint32_t)p[0] + ((uint32_t)p[1] << 8) + - ((uint32_t)p[2] << 16) + ((uint32_t)p[3] << 24); -#endif -} - -static inline void set_16(unsigned char *p, uint16_t v) -{ -#if defined(__i386__) || defined(__x86_64__) - /* Littleendian and unaligned-capable */ - *(uint16_t *)p = v; -#else - p[0] = (v & 0xff); - p[1] = ((v >> 8) & 0xff); -#endif -} - -static inline void set_32(unsigned char *p, uint32_t v) -{ -#if defined(__i386__) || defined(__x86_64__) - /* Littleendian and unaligned-capable */ - *(uint32_t *)p = v; -#else - p[0] = (v & 0xff); - p[1] = ((v >> 8) & 0xff); - p[2] = ((v >> 16) & 0xff); - p[3] = ((v >> 24) & 0xff); -#endif -} - #ifndef EXT2_SUPER_OFFSET #define EXT2_SUPER_OFFSET 1024 #endif -#define SECTOR_SHIFT 9 /* 512-byte sectors */ -#define SECTOR_SIZE (1 << SECTOR_SHIFT) - const char *program; /* @@ -490,6 +450,7 @@ patch_file_and_bootblock(int fd, int dirfd, int devfd) dprintf("directory inode = %lu\n", (unsigned long) dirst.st_ino); nsect = (boot_image_len+SECTOR_SIZE-1) >> SECTOR_SHIFT; + nsect += 2; /* Two sectors for the ADV */ sectp = alloca(sizeof(uint32_t)*nsect); if ( sectmap(fd, sectp, nsect) ) { perror("bmap"); @@ -505,9 +466,10 @@ patch_file_and_bootblock(int fd, int dirfd, int devfd) patcharea = p+8; /* Set up the totals */ - dw = boot_image_len >> 2; /* COMPLETE dwords! */ + dw = boot_image_len >> 2; /* COMPLETE dwords, excluding ADV */ set_16(patcharea, dw); - set_16(patcharea+2, nsect); /* Does not include the first sector! */ + set_16(patcharea+2, nsect); /* Not including the first sector, but + including the ADV */ set_32(patcharea+8, dirst.st_ino); /* "Current" directory */ /* Set the sector pointers */ @@ -530,6 +492,163 @@ patch_file_and_bootblock(int fd, int dirfd, int devfd) } /* + * Read the ADV from an existing instance, or initialize if invalid. + * Returns -1 on fatal errors, 0 if ADV is okay, and 1 if no valid + * ADV was found. + */ +int +read_adv(const char *path) +{ + char *file; + int fd = -1; + struct stat st; + int err = 0; + + asprintf(&file, "%s%sextlinux.sys", + path, + path[0] && path[strlen(path)-1] == '/' ? "" : "/"); + + if ( !file ) { + perror(program); + return -1; + } + + fd = open(file, O_RDONLY); + if ( fd < 0 ) { + if ( errno != ENOENT ) { + err = -1; + } else { + syslinux_reset_adv(syslinux_adv); + } + } else if (fstat(fd, &st)) { + err = -1; + } else if (st.st_size < 2*ADV_SIZE) { + /* Too small to be useful */ + syslinux_reset_adv(syslinux_adv); + err = 0; /* Nothing to read... */ + } else if (xpread(fd, syslinux_adv, 2*ADV_SIZE, + st.st_size-2*ADV_SIZE) != 2*ADV_SIZE) { + err = -1; + } else { + /* We got it... maybe? */ + err = syslinux_validate_adv(syslinux_adv) ? 1 : 0; + } + + if (err < 0) + perror(file); + + if (fd >= 0) + close(fd); + if (file) + free(file); + + return err; +} + +/* + * Update the ADV in an existing installation. + */ +int +write_adv(const char *path) +{ + unsigned char advtmp[2*ADV_SIZE]; + char *file; + int fd = -1; + struct stat st, xst; + int err = 0; + int flags, nflags; + + asprintf(&file, "%s%sextlinux.sys", + path, + path[0] && path[strlen(path)-1] == '/' ? "" : "/"); + + if ( !file ) { + perror(program); + return -1; + } + + fd = open(file, O_RDONLY); + if ( fd < 0 ) { + err = -1; + } else if (fstat(fd, &st)) { + err = -1; + } else if (st.st_size < 2*ADV_SIZE) { + /* Too small to be useful */ + err = -2; + } else if (xpread(fd, advtmp, 2*ADV_SIZE, + st.st_size-2*ADV_SIZE) != 2*ADV_SIZE) { + err = -1; + } else { + /* We got it... maybe? */ + err = syslinux_validate_adv(advtmp) ? -2 : 0; + if (!err) { + /* Got a good one, write our own ADV here */ + if (!ioctl(fd, EXT2_IOC_GETFLAGS, &flags)) { + nflags = flags & ~EXT2_IMMUTABLE_FL; + if (nflags != flags) + ioctl(fd, EXT2_IOC_SETFLAGS, &nflags); + } + if (!(st.st_mode & S_IWUSR)) + fchmod(fd, st.st_mode | S_IWUSR); + + /* Need to re-open read-write */ + close(fd); + fd = open(file, O_RDWR|O_SYNC); + if (fd < 0) { + err = -1; + } else if (fstat(fd, &xst) || xst.st_ino != st.st_ino || + xst.st_dev != st.st_dev || xst.st_size != st.st_size) { + fprintf(stderr, "%s: race condition on write\n", file); + err = -2; + } + /* Write our own version ... */ + if (xpwrite(fd, syslinux_adv, 2*ADV_SIZE, + st.st_size-2*ADV_SIZE) != 2*ADV_SIZE) { + err = -1; + } + + sync(); + + if (!(st.st_mode & S_IWUSR)) + fchmod(fd, st.st_mode); + + if (nflags != flags) + ioctl(fd, EXT2_IOC_SETFLAGS, &flags); + } + } + + if (err == -2) + fprintf(stderr, "%s: cannot write auxilliary data (need --update)?\n", + file); + else if (err == -1) + perror(file); + + if (fd >= 0) + close(fd); + if (file) + free(file); + + return err; +} + +/* + * Make any user-specified ADV modifications + */ +int modify_adv(void) +{ + int rv = 0; + + if (opt.set_once) { + if (syslinux_setadv(ADV_BOOTONCE, strlen(opt.set_once), opt.set_once)) { + fprintf(stderr, "%s: not enough space for boot-once command\n", program); + rv = -1; + } + } + + return rv; +} + +/* * Install the boot block on the specified device. * Must be run AFTER install_file()! */ @@ -595,14 +714,15 @@ install_file(const char *path, int devfd, struct stat *rst) } close(fd); - fd = open(file, O_WRONLY|O_TRUNC|O_CREAT, S_IRUSR|S_IRGRP|S_IROTH); + fd = open(file, O_WRONLY|O_TRUNC|O_CREAT|O_SYNC, S_IRUSR|S_IRGRP|S_IROTH); if ( fd < 0 ) { perror(file); goto bail; } /* Write it the first time */ - if ( xpwrite(fd, boot_image, boot_image_len, 0) != boot_image_len ) { + if ( xpwrite(fd, boot_image, boot_image_len, 0) != boot_image_len || + xpwrite(fd, syslinux_adv, 2*ADV_SIZE, boot_image_len) != 2*ADV_SIZE ) { fprintf(stderr, "%s: write failure on %s\n", program, file); goto bail; } @@ -610,8 +730,9 @@ install_file(const char *path, int devfd, struct stat *rst) /* Map the file, and patch the initial sector accordingly */ patch_file_and_bootblock(fd, dirfd, devfd); - /* Write it again - this relies on the file being overwritten in place! */ - if ( xpwrite(fd, boot_image, boot_image_len, 0) != boot_image_len ) { + /* Write the first sector again - this relies on the file being + overwritten in place! */ + if ( xpwrite(fd, boot_image, SECTOR_SIZE, 0) != SECTOR_SIZE ) { fprintf(stderr, "%s: write failure on %s\n", program, file); goto bail; } @@ -665,6 +786,17 @@ static void device_cleanup(void) } #endif +/* Verify that a device fd and a pathname agree. + Return 0 on valid, -1 on error. */ +static int validate_device(const char *path, int devfd) +{ + struct stat pst, dst; + + if (stat(path, &pst) || fstat(devfd, &dst)) + return -1; + + return (pst.st_dev == dst.st_rdev) ? 0 : -1; +} int install_loader(const char *path, int update_only) @@ -738,12 +870,30 @@ install_loader(const char *path, int update_only) return 1; } + /* Verify that the device we opened is the device intended */ + if (validate_device(path, devfd)) { + fprintf(stderr, "%s: path %s doesn't match device %s\n", + program, path, devname); + return 1; + } + if ( update_only && !already_installed(devfd) ) { fprintf(stderr, "%s: no previous extlinux boot sector found\n", program); return 1; } - install_file(path, devfd, &fst); + /* Read a pre-existing ADV, if already installed */ + if (opt.reset_adv) + syslinux_reset_adv(syslinux_adv); + else if (read_adv(path) < 0) + return 1; + + if (modify_adv() < 0) + return 1; + + /* Install extlinux.sys */ + if (install_file(path, devfd, &fst)) + return 1; if ( fst.st_dev != st.st_dev ) { fprintf(stderr, "%s: file system changed under us - aborting!\n", @@ -759,6 +909,26 @@ install_loader(const char *path, int update_only) return rv; } +/* + * Modify the ADV of an existing installation + */ +int +modify_existing_adv(const char *path) +{ + if (opt.reset_adv) + syslinux_reset_adv(syslinux_adv); + else if (read_adv(path) < 0) + return 1; + + if (modify_adv() < 0) + return 1; + + if (write_adv(path) < 0) + return 1; + + return 0; +} + int main(int argc, char *argv[]) { @@ -804,6 +974,15 @@ main(int argc, char *argv[]) case 'h': usage(0); break; + case 'o': + opt.set_once = optarg; + break; + case 'O': + opt.set_once = ""; + break; + case OPT_RESET_ADV: + opt.reset_adv = 1; + break; case 'v': fputs("extlinux " VERSION "\n", stderr); exit(0); @@ -818,9 +997,11 @@ main(int argc, char *argv[]) usage(EX_USAGE); if ( update_only == -1 ) { - fprintf(stderr, "%s: warning: a future version will require " - "--install or --update\n", program); - update_only = 0; + if (opt.reset_adv || opt.set_once) { + return modify_existing_adv(directory); + } else { + usage(EX_USAGE); + } } return install_loader(directory, update_only); |