From 660d3eac7782f63ae220ac4654e784f5dac1adc6 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Fri, 14 Dec 2007 15:14:10 -0800 Subject: [PATCH] Add missing libinstaller files Files missing from previous checkin, sigh. --- libinstaller/advconst.h | 1 + libinstaller/setadv.c | 160 ++++++++++++++++++++++++++++++++++++++++++++++++ libinstaller/syslxint.h | 74 ++++++++++++++++++++++ 3 files changed, 235 insertions(+) create mode 120000 libinstaller/advconst.h create mode 100644 libinstaller/setadv.c create mode 100644 libinstaller/syslxint.h diff --git a/libinstaller/advconst.h b/libinstaller/advconst.h new file mode 120000 index 0000000..044572b --- /dev/null +++ b/libinstaller/advconst.h @@ -0,0 +1 @@ +../com32/include/syslinux/advconst.h \ No newline at end of file diff --git a/libinstaller/setadv.c b/libinstaller/setadv.c new file mode 100644 index 0000000..e786e40 --- /dev/null +++ b/libinstaller/setadv.c @@ -0,0 +1,160 @@ +/* ----------------------------------------------------------------------- * + * + * Copyright 2007 H. Peter Anvin - All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, Inc., 53 Temple Place Ste 330, + * Boston MA 02111-1307, USA; either version 2 of the License, or + * (at your option) any later version; incorporated herein by reference. + * + * ----------------------------------------------------------------------- */ + +/* + * setadv.c + * + * (Over)write a data item in the auxilliary data vector. To + * delete an item, set its length to zero. + * + * Return 0 on success, -1 on error, and set errno. + * + */ + +#include +#include +#include "syslxint.h" + +unsigned char syslinux_adv[2*ADV_SIZE]; + +#define ADV_MAGIC1 0x5a2d2fa5 /* Head signature */ +#define ADV_MAGIC2 0xa3041767 /* Total checksum */ +#define ADV_MAGIC3 0xdd28bf64 /* Tail signature */ + +static void cleanup_adv(unsigned char *advbuf) +{ + int i; + uint32_t csum; + + /* Make sure both copies agree, and update the checksum */ + set_32(advbuf, ADV_MAGIC1); + + csum = ADV_MAGIC2; + for (i = 8; i < ADV_SIZE-4; i += 4) + csum -= get_32(advbuf+i); + + set_32(advbuf+4, csum); + set_32(advbuf+ADV_SIZE-4, ADV_MAGIC3); + + memcpy(advbuf+ADV_SIZE, advbuf, ADV_SIZE); +} + +int syslinux_setadv(int tag, size_t size, const void *data) +{ + uint8_t *p; + size_t left; + uint8_t advtmp[ADV_SIZE]; + + if ((unsigned)tag-1 > 254) { + errno = EINVAL; + return -1; /* Impossible tag value */ + } + + if (size > 255) { + errno = ENOSPC; /* Max 255 bytes for a data item */ + return -1; + } + + left = ADV_LEN; + p = advtmp; + memcpy(p, syslinux_adv+2*4, left); /* Make working copy */ + + while (left >= 2) { + uint8_t ptag = p[0]; + size_t plen = p[1]+2; + + if (ptag == ADV_END) + break; + + if (ptag == tag) { + /* Found our tag. Delete it. */ + + if (plen >= left) { + /* Entire remainder is our tag */ + break; + } + memmove(p, p+plen, left-plen); + } else { + /* Not our tag */ + if (plen > left) + break; /* Corrupt tag (overrun) - overwrite it */ + + left -= plen; + p += plen; + } + } + + /* Now (p, left) reflects the position to write in and how much space + we have for our data. */ + + if (size) { + if (left < size+2) { + errno = ENOSPC; /* Not enough space for data */ + return -1; + } + + *p++ = tag; + *p++ = size; + memcpy(p, data, size); + p += size; + left -= size+2; + } + + memset(p, 0, left); + + /* If we got here, everything went OK, commit the write */ + memcpy(syslinux_adv+2*4, advtmp, ADV_LEN); + cleanup_adv(syslinux_adv); + + return 0; +} + +void syslinux_reset_adv(unsigned char *advbuf) +{ + /* Create an all-zero ADV */ + memset(advbuf+2*4, 0, ADV_LEN); + cleanup_adv(advbuf); +} + +static int adv_consistent(const unsigned char *p) +{ + int i; + uint32_t csum; + + if (get_32(p) != ADV_MAGIC1 || get_32(p+ADV_SIZE-4) != ADV_MAGIC3) + return 0; + + csum = 0; + for (i = 4; i < ADV_SIZE-4; i += 4) + csum += get_32(p+i); + + return csum == ADV_MAGIC2; +} + +/* + * Verify that an in-memory ADV is consistent, making the copies consistent. + * If neither copy is OK, return -1 and call syslinux_reset_adv(). + */ +int syslinux_validate_adv(unsigned char *advbuf) +{ + if (adv_consistent(advbuf+0*ADV_SIZE)) { + memcpy(advbuf+ADV_SIZE, advbuf, ADV_SIZE); + return 0; + } else if (adv_consistent(advbuf+1*ADV_SIZE)) { + memcpy(advbuf, advbuf+ADV_SIZE, ADV_SIZE); + return 0; + } else { + syslinux_reset_adv(advbuf); + return -1; + } +} + diff --git a/libinstaller/syslxint.h b/libinstaller/syslxint.h new file mode 100644 index 0000000..e296df1 --- /dev/null +++ b/libinstaller/syslxint.h @@ -0,0 +1,74 @@ +/* ----------------------------------------------------------------------- * + * + * Copyright 2007 H. Peter Anvin - All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, Inc., 53 Temple Place Ste 330, + * Boston MA 02111-1307, USA; either version 2 of the License, or + * (at your option) any later version; incorporated herein by reference. + * + * ----------------------------------------------------------------------- */ + +#ifndef SYSLXINT_H +#define SYSLXINT_H + +#include "syslinux.h" + +/* + * 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 +} + +#define SECTOR_SHIFT 9 /* 512-byte sectors */ +#define SECTOR_SIZE (1 << SECTOR_SHIFT) + +#endif /* SYSLXINT_H */ -- 2.7.4