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putty/misc.c

669 строки
15 KiB
C
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#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <ctype.h>
#include <assert.h>
#include "putty.h"
/* ----------------------------------------------------------------------
* String handling routines.
*/
char *dupstr(const char *s)
{
int len = strlen(s);
char *p = smalloc(len + 1);
strcpy(p, s);
return p;
}
/* Allocate the concatenation of N strings. Terminate arg list with NULL. */
char *dupcat(const char *s1, ...)
{
int len;
char *p, *q, *sn;
va_list ap;
len = strlen(s1);
va_start(ap, s1);
while (1) {
sn = va_arg(ap, char *);
if (!sn)
break;
len += strlen(sn);
}
va_end(ap);
p = smalloc(len + 1);
strcpy(p, s1);
q = p + strlen(p);
va_start(ap, s1);
while (1) {
sn = va_arg(ap, char *);
if (!sn)
break;
strcpy(q, sn);
q += strlen(q);
}
va_end(ap);
return p;
}
/*
* Do an sprintf(), but into a custom-allocated buffer.
*
* Irritatingly, we don't seem to be able to do this portably using
* vsnprintf(), because there appear to be issues with re-using the
* same va_list for two calls, and the excellent C99 va_copy is not
* yet widespread. Bah. Instead I'm going to do a horrid, horrid
* hack, in which I trawl the format string myself, work out the
* maximum length of each format component, and resize the buffer
* before printing it.
*/
char *dupprintf(const char *fmt, ...)
{
char *ret;
va_list ap;
va_start(ap, fmt);
ret = dupvprintf(fmt, ap);
va_end(ap);
return ret;
}
char *dupvprintf(const char *fmt, va_list ap)
{
char *buf;
int len, size;
buf = smalloc(512);
size = 512;
while (1) {
#ifdef _WINDOWS
#define vsnprintf _vsnprintf
#endif
len = vsnprintf(buf, size, fmt, ap);
if (len >= 0 && len < size) {
/* This is the C99-specified criterion for snprintf to have
* been completely successful. */
return buf;
} else if (len > 0) {
/* This is the C99 error condition: the returned length is
* the required buffer size not counting the NUL. */
size = len + 1;
} else {
/* This is the pre-C99 glibc error condition: <0 means the
* buffer wasn't big enough, so we enlarge it a bit and hope. */
size += 512;
}
buf = srealloc(buf, size);
}
}
/* ----------------------------------------------------------------------
* Base64 encoding routine. This is required in public-key writing
* but also in HTTP proxy handling, so it's centralised here.
*/
void base64_encode_atom(unsigned char *data, int n, char *out)
{
static const char base64_chars[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
unsigned word;
word = data[0] << 16;
if (n > 1)
word |= data[1] << 8;
if (n > 2)
word |= data[2];
out[0] = base64_chars[(word >> 18) & 0x3F];
out[1] = base64_chars[(word >> 12) & 0x3F];
if (n > 1)
out[2] = base64_chars[(word >> 6) & 0x3F];
else
out[2] = '=';
if (n > 2)
out[3] = base64_chars[word & 0x3F];
else
out[3] = '=';
}
/* ----------------------------------------------------------------------
* Generic routines to deal with send buffers: a linked list of
* smallish blocks, with the operations
*
* - add an arbitrary amount of data to the end of the list
* - remove the first N bytes from the list
* - return a (pointer,length) pair giving some initial data in
* the list, suitable for passing to a send or write system
* call
* - retrieve a larger amount of initial data from the list
* - return the current size of the buffer chain in bytes
*/
#define BUFFER_GRANULE 512
struct bufchain_granule {
struct bufchain_granule *next;
int buflen, bufpos;
char buf[BUFFER_GRANULE];
};
void bufchain_init(bufchain *ch)
{
ch->head = ch->tail = NULL;
ch->buffersize = 0;
}
void bufchain_clear(bufchain *ch)
{
struct bufchain_granule *b;
while (ch->head) {
b = ch->head;
ch->head = ch->head->next;
sfree(b);
}
ch->tail = NULL;
ch->buffersize = 0;
}
int bufchain_size(bufchain *ch)
{
return ch->buffersize;
}
void bufchain_add(bufchain *ch, const void *data, int len)
{
const char *buf = (const char *)data;
ch->buffersize += len;
if (ch->tail && ch->tail->buflen < BUFFER_GRANULE) {
int copylen = min(len, BUFFER_GRANULE - ch->tail->buflen);
memcpy(ch->tail->buf + ch->tail->buflen, buf, copylen);
buf += copylen;
len -= copylen;
ch->tail->buflen += copylen;
}
while (len > 0) {
int grainlen = min(len, BUFFER_GRANULE);
struct bufchain_granule *newbuf;
newbuf = smalloc(sizeof(struct bufchain_granule));
newbuf->bufpos = 0;
newbuf->buflen = grainlen;
memcpy(newbuf->buf, buf, grainlen);
buf += grainlen;
len -= grainlen;
if (ch->tail)
ch->tail->next = newbuf;
else
ch->head = ch->tail = newbuf;
newbuf->next = NULL;
ch->tail = newbuf;
}
}
void bufchain_consume(bufchain *ch, int len)
{
struct bufchain_granule *tmp;
assert(ch->buffersize >= len);
while (len > 0) {
int remlen = len;
assert(ch->head != NULL);
if (remlen >= ch->head->buflen - ch->head->bufpos) {
remlen = ch->head->buflen - ch->head->bufpos;
tmp = ch->head;
ch->head = tmp->next;
sfree(tmp);
if (!ch->head)
ch->tail = NULL;
} else
ch->head->bufpos += remlen;
ch->buffersize -= remlen;
len -= remlen;
}
}
void bufchain_prefix(bufchain *ch, void **data, int *len)
{
*len = ch->head->buflen - ch->head->bufpos;
*data = ch->head->buf + ch->head->bufpos;
}
void bufchain_fetch(bufchain *ch, void *data, int len)
{
struct bufchain_granule *tmp;
char *data_c = (char *)data;
tmp = ch->head;
assert(ch->buffersize >= len);
while (len > 0) {
int remlen = len;
assert(tmp != NULL);
if (remlen >= tmp->buflen - tmp->bufpos)
remlen = tmp->buflen - tmp->bufpos;
memcpy(data_c, tmp->buf + tmp->bufpos, remlen);
tmp = tmp->next;
len -= remlen;
data_c += remlen;
}
}
/* ----------------------------------------------------------------------
* My own versions of malloc, realloc and free. Because I want
* malloc and realloc to bomb out and exit the program if they run
* out of memory, realloc to reliably call malloc if passed a NULL
* pointer, and free to reliably do nothing if passed a NULL
* pointer. We can also put trace printouts in, if we need to; and
* we can also replace the allocator with an ElectricFence-like
* one.
*/
#ifdef MINEFIELD
/*
* Minefield - a Windows equivalent for Electric Fence
*/
#define PAGESIZE 4096
/*
* Design:
*
* We start by reserving as much virtual address space as Windows
* will sensibly (or not sensibly) let us have. We flag it all as
* invalid memory.
*
* Any allocation attempt is satisfied by committing one or more
* pages, with an uncommitted page on either side. The returned
* memory region is jammed up against the _end_ of the pages.
*
* Freeing anything causes instantaneous decommitment of the pages
* involved, so stale pointers are caught as soon as possible.
*/
static int minefield_initialised = 0;
static void *minefield_region = NULL;
static long minefield_size = 0;
static long minefield_npages = 0;
static long minefield_curpos = 0;
static unsigned short *minefield_admin = NULL;
static void *minefield_pages = NULL;
static void minefield_admin_hide(int hide)
{
int access = hide ? PAGE_NOACCESS : PAGE_READWRITE;
VirtualProtect(minefield_admin, minefield_npages * 2, access, NULL);
}
static void minefield_init(void)
{
int size;
int admin_size;
int i;
for (size = 0x40000000; size > 0; size = ((size >> 3) * 7) & ~0xFFF) {
minefield_region = VirtualAlloc(NULL, size,
MEM_RESERVE, PAGE_NOACCESS);
if (minefield_region)
break;
}
minefield_size = size;
/*
* Firstly, allocate a section of that to be the admin block.
* We'll need a two-byte field for each page.
*/
minefield_admin = minefield_region;
minefield_npages = minefield_size / PAGESIZE;
admin_size = (minefield_npages * 2 + PAGESIZE - 1) & ~(PAGESIZE - 1);
minefield_npages = (minefield_size - admin_size) / PAGESIZE;
minefield_pages = (char *) minefield_region + admin_size;
/*
* Commit the admin region.
*/
VirtualAlloc(minefield_admin, minefield_npages * 2,
MEM_COMMIT, PAGE_READWRITE);
/*
* Mark all pages as unused (0xFFFF).
*/
for (i = 0; i < minefield_npages; i++)
minefield_admin[i] = 0xFFFF;
/*
* Hide the admin region.
*/
minefield_admin_hide(1);
minefield_initialised = 1;
}
static void minefield_bomb(void)
{
div(1, *(int *) minefield_pages);
}
static void *minefield_alloc(int size)
{
int npages;
int pos, lim, region_end, region_start;
int start;
int i;
npages = (size + PAGESIZE - 1) / PAGESIZE;
minefield_admin_hide(0);
/*
* Search from current position until we find a contiguous
* bunch of npages+2 unused pages.
*/
pos = minefield_curpos;
lim = minefield_npages;
while (1) {
/* Skip over used pages. */
while (pos < lim && minefield_admin[pos] != 0xFFFF)
pos++;
/* Count unused pages. */
start = pos;
while (pos < lim && pos - start < npages + 2 &&
minefield_admin[pos] == 0xFFFF)
pos++;
if (pos - start == npages + 2)
break;
/* If we've reached the limit, reset the limit or stop. */
if (pos >= lim) {
if (lim == minefield_npages) {
/* go round and start again at zero */
lim = minefield_curpos;
pos = 0;
} else {
minefield_admin_hide(1);
return NULL;
}
}
}
minefield_curpos = pos - 1;
/*
* We have npages+2 unused pages starting at start. We leave
* the first and last of these alone and use the rest.
*/
region_end = (start + npages + 1) * PAGESIZE;
region_start = region_end - size;
/* FIXME: could align here if we wanted */
/*
* Update the admin region.
*/
for (i = start + 2; i < start + npages + 1; i++)
minefield_admin[i] = 0xFFFE; /* used but no region starts here */
minefield_admin[start + 1] = region_start % PAGESIZE;
minefield_admin_hide(1);
VirtualAlloc((char *) minefield_pages + region_start, size,
MEM_COMMIT, PAGE_READWRITE);
return (char *) minefield_pages + region_start;
}
static void minefield_free(void *ptr)
{
int region_start, i, j;
minefield_admin_hide(0);
region_start = (char *) ptr - (char *) minefield_pages;
i = region_start / PAGESIZE;
if (i < 0 || i >= minefield_npages ||
minefield_admin[i] != region_start % PAGESIZE)
minefield_bomb();
for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++) {
minefield_admin[j] = 0xFFFF;
}
VirtualFree(ptr, j * PAGESIZE - region_start, MEM_DECOMMIT);
minefield_admin_hide(1);
}
static int minefield_get_size(void *ptr)
{
int region_start, i, j;
minefield_admin_hide(0);
region_start = (char *) ptr - (char *) minefield_pages;
i = region_start / PAGESIZE;
if (i < 0 || i >= minefield_npages ||
minefield_admin[i] != region_start % PAGESIZE)
minefield_bomb();
for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++);
minefield_admin_hide(1);
return j * PAGESIZE - region_start;
}
static void *minefield_c_malloc(size_t size)
{
if (!minefield_initialised)
minefield_init();
return minefield_alloc(size);
}
static void minefield_c_free(void *p)
{
if (!minefield_initialised)
minefield_init();
minefield_free(p);
}
/*
* realloc _always_ moves the chunk, for rapid detection of code
* that assumes it won't.
*/
static void *minefield_c_realloc(void *p, size_t size)
{
size_t oldsize;
void *q;
if (!minefield_initialised)
minefield_init();
q = minefield_alloc(size);
oldsize = minefield_get_size(p);
memcpy(q, p, (oldsize < size ? oldsize : size));
minefield_free(p);
return q;
}
#endif /* MINEFIELD */
#ifdef MALLOC_LOG
static FILE *fp = NULL;
static char *mlog_file = NULL;
static int mlog_line = 0;
void mlog(char *file, int line)
{
mlog_file = file;
mlog_line = line;
if (!fp) {
fp = fopen("putty_mem.log", "w");
setvbuf(fp, NULL, _IONBF, BUFSIZ);
}
if (fp)
fprintf(fp, "%s:%d: ", file, line);
}
#endif
void *safemalloc(size_t size)
{
void *p;
#ifdef MINEFIELD
p = minefield_c_malloc(size);
#else
p = malloc(size);
#endif
if (!p) {
char str[200];
#ifdef MALLOC_LOG
sprintf(str, "Out of memory! (%s:%d, size=%d)",
mlog_file, mlog_line, size);
fprintf(fp, "*** %s\n", str);
fclose(fp);
#else
strcpy(str, "Out of memory!");
#endif
modalfatalbox(str);
}
#ifdef MALLOC_LOG
if (fp)
fprintf(fp, "malloc(%d) returns %p\n", size, p);
#endif
return p;
}
void *saferealloc(void *ptr, size_t size)
{
void *p;
if (!ptr) {
#ifdef MINEFIELD
p = minefield_c_malloc(size);
#else
p = malloc(size);
#endif
} else {
#ifdef MINEFIELD
p = minefield_c_realloc(ptr, size);
#else
p = realloc(ptr, size);
#endif
}
if (!p) {
char str[200];
#ifdef MALLOC_LOG
sprintf(str, "Out of memory! (%s:%d, size=%d)",
mlog_file, mlog_line, size);
fprintf(fp, "*** %s\n", str);
fclose(fp);
#else
strcpy(str, "Out of memory!");
#endif
modalfatalbox(str);
}
#ifdef MALLOC_LOG
if (fp)
fprintf(fp, "realloc(%p,%d) returns %p\n", ptr, size, p);
#endif
return p;
}
void safefree(void *ptr)
{
if (ptr) {
#ifdef MALLOC_LOG
if (fp)
fprintf(fp, "free(%p)\n", ptr);
#endif
#ifdef MINEFIELD
minefield_c_free(ptr);
#else
free(ptr);
#endif
}
#ifdef MALLOC_LOG
else if (fp)
fprintf(fp, "freeing null pointer - no action taken\n");
#endif
}
/* ----------------------------------------------------------------------
* Debugging routines.
*/
#ifdef DEBUG
static FILE *debug_fp = NULL;
static HANDLE debug_hdl = INVALID_HANDLE_VALUE;
static int debug_got_console = 0;
static void dputs(char *buf)
{
DWORD dw;
if (!debug_got_console) {
if (AllocConsole()) {
debug_got_console = 1;
debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE);
}
}
if (!debug_fp) {
debug_fp = fopen("debug.log", "w");
}
if (debug_hdl != INVALID_HANDLE_VALUE) {
WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL);
}
fputs(buf, debug_fp);
fflush(debug_fp);
}
void dprintf(char *fmt, ...)
{
char *buf;
va_list ap;
va_start(ap, fmt);
buf = dupvprintf(fmt, ap);
dputs(buf);
sfree(buf);
va_end(ap);
}
void debug_memdump(void *buf, int len, int L)
{
int i;
unsigned char *p = buf;
char foo[17];
if (L) {
int delta;
dprintf("\t%d (0x%x) bytes:\n", len, len);
delta = 15 & (int) p;
p -= delta;
len += delta;
}
for (; 0 < len; p += 16, len -= 16) {
dputs(" ");
if (L)
dprintf("%p: ", p);
strcpy(foo, "................"); /* sixteen dots */
for (i = 0; i < 16 && i < len; ++i) {
if (&p[i] < (unsigned char *) buf) {
dputs(" "); /* 3 spaces */
foo[i] = ' ';
} else {
dprintf("%c%02.2x",
&p[i] != (unsigned char *) buf
&& i % 4 ? '.' : ' ', p[i]
);
if (p[i] >= ' ' && p[i] <= '~')
foo[i] = (char) p[i];
}
}
foo[i] = '\0';
dprintf("%*s%s\n", (16 - i) * 3 + 2, "", foo);
}
}
#endif /* def DEBUG */
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