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fix a bug in which evbuffer_add_vfprintf would loop forever; avoid

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fragmentation in evbuffer_expand by increasing the size of the last buffer
in the chain; as a result with have to keep track of the previous_to_last
chain;   provide a evbuffer_validate() function in the regression test to
make sure that all evbuffer are internally consistent.


svn:r699
This commit is contained in:
Niels Provos 2008-03-31 02:04:34 +00:00
parent 3ef1f50415
commit 193c06a7ed
3 changed files with 211 additions and 34 deletions
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109
buffer.c
View File

@ -122,6 +122,37 @@ evbuffer_length(struct evbuffer *buffer)
return (buffer->total_len);
}
#define ZERO_CHAIN(dst) do { \
(dst)->first = NULL; \
(dst)->last = NULL; \
(dst)->previous_to_last = NULL; \
(dst)->total_len = 0; \
} while (0)
#define COPY_CHAIN(dst, src) do { \
(dst)->first = (src)->first; \
(dst)->previous_to_last = (src)->previous_to_last; \
(dst)->last = (src)->last; \
(dst)->total_len = (src)->total_len; \
} while (0)
#define APPEND_CHAIN(dst, src) do { \
(dst)->last->next = (src)->first; \
(dst)->previous_to_last = (src)->previous_to_last ? \
(src)->previous_to_last : (dst)->last; \
(dst)->last = (src)->last; \
(dst)->total_len += (src)->total_len; \
} while (0)
#define PREPEND_CHAIN(dst, src) do { \
(src)->last->next = (dst)->first; \
(dst)->first = (src)->first; \
(dst)->total_len += (src)->total_len; \
if ((dst)->previous_to_last == NULL) \
(dst)->previous_to_last = (src)->last; \
} while (0)
int
evbuffer_add_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf)
{
@ -129,19 +160,13 @@ evbuffer_add_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf)
size_t in_total_len = inbuf->total_len;
if (out_total_len == 0) {
outbuf->first = inbuf->first;
outbuf->last = inbuf->last;
outbuf->total_len = in_total_len;
COPY_CHAIN(outbuf, inbuf);
} else {
outbuf->last->next = inbuf->first;
outbuf->last = inbuf->last;
outbuf->total_len += in_total_len;
APPEND_CHAIN(outbuf, inbuf);
}
/* remove everything from inbuf */
inbuf->first = NULL;
inbuf->last = NULL;
inbuf->total_len = 0;
ZERO_CHAIN(inbuf);
if (inbuf->cb != NULL && inbuf->total_len != in_total_len)
(*inbuf->cb)(inbuf, in_total_len, inbuf->total_len,
@ -163,19 +188,13 @@ evbuffer_prepend_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf)
return;
if (out_total_len == 0) {
outbuf->first = inbuf->first;
outbuf->last = inbuf->last;
outbuf->total_len = in_total_len;
COPY_CHAIN(outbuf, inbuf);
} else {
inbuf->last->next = outbuf->first;
outbuf->first = inbuf->first;
outbuf->total_len += in_total_len;
PREPEND_CHAIN(outbuf, inbuf);
}
/* remove everything from inbuf */
inbuf->first = NULL;
inbuf->last = NULL;
inbuf->total_len = 0;
ZERO_CHAIN(inbuf);
if (inbuf->cb != NULL && inbuf->total_len != in_total_len)
(*inbuf->cb)(inbuf, in_total_len, inbuf->total_len,
@ -201,8 +220,7 @@ evbuffer_drain(struct evbuffer *buf, size_t len)
event_free(chain);
}
buf->total_len = 0;
buf->first = buf->last = NULL;
ZERO_CHAIN(buf);
} else {
buf->total_len -= len;
@ -214,6 +232,8 @@ evbuffer_drain(struct evbuffer *buf, size_t len)
}
buf->first = chain;
if (buf->first == buf->last)
buf->previous_to_last = NULL;
chain->misalign += len;
chain->off -= len;
}
@ -254,6 +274,8 @@ evbuffer_remove(struct evbuffer *buf, void *data_out, size_t datlen)
buf->first = chain;
if (chain == NULL)
buf->last = NULL;
if (buf->first == buf->last)
buf->previous_to_last = NULL;
if (datlen) {
memcpy(data, chain->buffer + chain->misalign, datlen);
@ -276,7 +298,8 @@ int
evbuffer_remove_buffer(struct evbuffer *src, struct evbuffer *dst,
size_t datlen)
{
struct evbuffer_chain *chain = src->first, *previous = chain;
struct evbuffer_chain *chain = src->first;
struct evbuffer_chain *previous = chain, *previous_to_previous = NULL;
size_t nread = 0;
/* short-cut if there is no more data buffered */
@ -293,6 +316,7 @@ evbuffer_remove_buffer(struct evbuffer *src, struct evbuffer *dst,
while (chain->off <= datlen) {
nread += chain->off;
datlen -= chain->off;
previous_to_previous = previous;
previous = chain;
chain = chain->next;
}
@ -304,9 +328,12 @@ evbuffer_remove_buffer(struct evbuffer *src, struct evbuffer *dst,
} else {
dst->last->next = src->first;
}
dst->previous_to_last = previous_to_previous;
dst->last = previous;
previous->next = NULL;
src->first = chain;
if (src->first == src->last)
src->previous_to_last = NULL;
dst->total_len += nread;
}
@ -383,8 +410,12 @@ evbuffer_pullup(struct evbuffer *buf, int size)
memcpy(buffer, chain->buffer + chain->misalign, size);
chain->misalign += size;
chain->off -= size;
if (chain == buf->last)
buf->previous_to_last = tmp;
} else {
buf->last = tmp;
/* the last is already the first, so we have no previous */
buf->previous_to_last = NULL;
}
tmp->next = chain;
@ -605,6 +636,7 @@ evbuffer_add(struct evbuffer *buf, const void *data_in, size_t datlen)
if (chain->next == NULL)
return (-1);
buf->last = chain->next;
buf->previous_to_last = chain;
buf->total_len += datlen;
memcpy(chain->buffer + chain->misalign + chain->off,
@ -646,13 +678,15 @@ evbuffer_prepend(struct evbuffer *buf, const void *data, size_t datlen)
chain->misalign -= datlen;
} else {
struct evbuffer_chain *tmp;
/* XXX we should copy as much of the data into chain as possible
* before we put any into tmp. */
/* XXX we should copy as much of the data into chain
* as possible before we put any into tmp. */
/* we need to add another chain */
if ((tmp = evbuffer_chain_new(datlen)) == NULL)
return (-1);
buf->first = tmp;
if (buf->previous_to_last == NULL)
buf->previous_to_last = tmp;
tmp->next = chain;
tmp->off = datlen;
@ -691,6 +725,7 @@ evbuffer_expand(struct evbuffer *buf, size_t datlen)
return (-1);
buf->first = buf->last = chain;
buf->previous_to_last = NULL;
return (0);
}
@ -700,25 +735,34 @@ evbuffer_expand(struct evbuffer *buf, size_t datlen)
if (chain->buffer_len >= need)
return (0);
/* If the misalignment plus the remaining space fulfils our data needs, we
* just force an alignment to happen. Afterwards, we have enough space.
/* If the misalignment plus the remaining space fulfils our
* data needs, we just force an alignment to happen.
* Afterwards, we have enough space.
*/
if (chain->buffer_len - chain->off >= datlen) {
evbuffer_chain_align(chain);
return (0);
}
/* avoid a memcpy if we can just append a new chain */
/* XXX in practice, does this result in lots of leftover space? */
length = chain->buffer_len << 1;
if (length < datlen)
length = datlen;
/* figure out how much space we need */
length = chain->buffer_len - chain->misalign + datlen;
tmp = evbuffer_chain_new(length);
if (tmp == NULL)
return (-1);
chain->next = tmp;
/* copy the data over that we had so far */
tmp->off = chain->off;
tmp->misalign = 0;
memcpy(tmp->buffer, chain->buffer + chain->misalign, chain->off);
/* fix up the chain */
if (buf->first == chain)
buf->first = tmp;
if (buf->previous_to_last)
buf->previous_to_last->next = tmp;
buf->last = tmp;
event_free(chain);
return (0);
}
@ -851,7 +895,6 @@ evbuffer_find(struct evbuffer *buffer, const u_char *what, size_t len)
int
evbuffer_add_vprintf(struct evbuffer *buf, const char *fmt, va_list ap)
{
struct evbuffer_chain *chain;
char *buffer;
size_t space;
size_t old_len = buf->total_len;
@ -862,8 +905,8 @@ evbuffer_add_vprintf(struct evbuffer *buf, const char *fmt, va_list ap)
if (evbuffer_expand(buf, 64) == -1)
return (-1);
chain = buf->last;
for (;;) {
struct evbuffer_chain *chain = buf->last;
size_t used = chain->misalign + chain->off;
buffer = (char *)chain->buffer + chain->misalign + chain->off;
assert(chain->buffer_len >= used);

1
evbuffer-internal.h
View File

@ -45,6 +45,7 @@ struct evbuffer_chain;
struct evbuffer {
struct evbuffer_chain *first;
struct evbuffer_chain *last;
struct evbuffer_chain *previous_to_last;
size_t total_len; /* total length of all buffers */

135
test/regress.c
View File

@ -53,10 +53,12 @@
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include "event.h"
#include "evutil.h"
#include "event-internal.h"
#include "evbuffer-internal.h"
#include "log.h"
#include "regress.h"
@ -890,6 +892,38 @@ test_nonpersist_readd(void)
cleanup_test();
}
/* validates that an evbuffer is good */
static void
evbuffer_validate(struct evbuffer *buf)
{
struct evbuffer_chain *chain, *previous = NULL;
size_t sum = 0;
if (buf->first == NULL) {
assert(buf->last == NULL);
assert(buf->previous_to_last == NULL);
assert(buf->total_len == 0);
}
if (buf->previous_to_last == NULL) {
assert(buf->first == buf->last);
}
chain = buf->first;
while (chain != NULL) {
sum += chain->off;
if (chain->next == NULL) {
assert(buf->previous_to_last == previous);
assert(buf->last == chain);
}
assert(chain->buffer_len >= chain->misalign + chain->off);
previous = chain;
chain = chain->next;
}
assert(sum == buf->total_len);
}
static void
test_evbuffer(void)
{
@ -900,19 +934,24 @@ test_evbuffer(void)
int i;
setup_test("Testing Evbuffer: ");
evbuffer_validate(evb);
evbuffer_add_printf(evb, "%s/%d", "hello", 1);
evbuffer_validate(evb);
if (EVBUFFER_LENGTH(evb) != 7 ||
strcmp((char*)EVBUFFER_DATA(evb), "hello/1") != 0)
goto out;
evbuffer_drain(evb, strlen("hello/"));
evbuffer_validate(evb);
if (EVBUFFER_LENGTH(evb) != 1 ||
strcmp((char*)EVBUFFER_DATA(evb), "1") != 0)
goto out;
evbuffer_add_printf(evb_two, "%s", "/hello");
evbuffer_validate(evb);
evbuffer_add_buffer(evb, evb_two);
evbuffer_validate(evb);
if (EVBUFFER_LENGTH(evb_two) != 0 ||
EVBUFFER_LENGTH(evb) != 7 ||
@ -921,6 +960,7 @@ test_evbuffer(void)
memset(buffer, 0, sizeof(buffer));
evbuffer_add(evb, buffer, sizeof(buffer));
evbuffer_validate(evb);
if (EVBUFFER_LENGTH(evb) != 7 + 512)
goto out;
@ -931,20 +971,29 @@ test_evbuffer(void)
goto out;
if (memcmp(tmp + 7, buffer, sizeof(buffer)) != 0)
goto out;
evbuffer_validate(evb);
evbuffer_prepend(evb, "something", 9);
evbuffer_validate(evb);
evbuffer_prepend(evb, "else", 4);
evbuffer_validate(evb);
tmp = (char *)evbuffer_pullup(evb, 4 + 9 + 7);
if (strncmp(tmp, "elsesomething1/hello", 4 + 9 + 7) != 0)
goto out;
evbuffer_validate(evb);
evbuffer_drain(evb, -1);
evbuffer_validate(evb);
evbuffer_drain(evb_two, -1);
evbuffer_validate(evb);
for (i = 0; i < 3; ++i) {
evbuffer_add(evb_two, buffer, sizeof(buffer));
evbuffer_validate(evb_two);
evbuffer_add_buffer(evb, evb_two);
evbuffer_validate(evb);
evbuffer_validate(evb_two);
}
if (EVBUFFER_LENGTH(evb_two) != 0 ||
@ -957,12 +1006,14 @@ test_evbuffer(void)
if (EVBUFFER_LENGTH(evb_two) != sz_tmp ||
EVBUFFER_LENGTH(evb) != sizeof(buffer) / 2)
goto out;
evbuffer_validate(evb);
if (memcmp(evbuffer_pullup(
evb, -1), buffer, sizeof(buffer) / 2) != 0 ||
memcmp(evbuffer_pullup(
evb_two, -1), buffer, sizeof(buffer) != 0))
goto out;
evbuffer_validate(evb);
test_ok = 1;
@ -986,123 +1037,169 @@ test_evbuffer_readln(void)
/* Test EOL_ANY. */
s = "complex silly newline\r\n\n\r\n\n\rmore\0\n";
evbuffer_add(evb, s, strlen(s)+2);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_ANY);
if (!cp || sz != strlen(cp) || strcmp(cp, "complex silly newline"))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_ANY);
if (!cp || sz != 5 || memcmp(cp, "more\0\0", 6))
goto done;
if (EVBUFFER_LENGTH(evb) != 0)
goto done;
evbuffer_validate(evb);
s = "\nno newline";
evbuffer_add(evb, s, strlen(s));
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_ANY);
if (!cp || sz || strcmp(cp, ""))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_ANY);
if (cp)
goto done;
evbuffer_validate(evb);
evbuffer_drain(evb, EVBUFFER_LENGTH(evb));
if (EVBUFFER_LENGTH(evb) != 0)
goto done;
evbuffer_validate(evb);
/* Test EOL_CRLF */
s = "Line with\rin the middle\nLine with good crlf\r\n\nfinal\n";
evbuffer_add(evb, s, strlen(s));
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF);
if (!cp || sz != strlen(cp) || strcmp(cp, "Line with\rin the middle"))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF);
if (!cp || sz != strlen(cp) || strcmp(cp, "Line with good crlf"))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF);
if (!cp || sz != strlen(cp) || strcmp(cp, ""))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF);
if (!cp || sz != strlen(cp) || strcmp(cp, "final"))
goto done;
s = "x";
evbuffer_validate(evb);
evbuffer_add(evb, s, 1);
evbuffer_validate(evb);
free(cp);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF);
if (cp)
goto done;
evbuffer_validate(evb);
/* Test CRLF_STRICT */
s = " and a bad crlf\nand a good one\r\n\r\nMore\r";
evbuffer_add(evb, s, strlen(s));
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF_STRICT);
if (!cp || sz != strlen(cp) ||
strcmp(cp, "x and a bad crlf\nand a good one"))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF_STRICT);
if (!cp || sz != strlen(cp) || strcmp(cp, ""))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF_STRICT);
if (cp)
goto done;
evbuffer_validate(evb);
evbuffer_add(evb, "\n", 1);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF_STRICT);
if (!cp || sz != strlen(cp) || strcmp(cp, "More"))
goto done;
if (EVBUFFER_LENGTH(evb) != 0)
goto done;
evbuffer_validate(evb);
/* Test LF */
s = "An\rand a nl\n\nText";
evbuffer_add(evb, s, strlen(s));
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_LF);
if (!cp || sz != strlen(cp) || strcmp(cp, "An\rand a nl"))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_LF);
if (!cp || sz != strlen(cp) || strcmp(cp, ""))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_LF);
if (cp)
goto done;
evbuffer_add(evb, "\n", 1);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_LF);
if (!cp || sz != strlen(cp) || strcmp(cp, "Text"))
goto done;
evbuffer_validate(evb);
/* Test CRLF_STRICT - across boundaries*/
s = " and a bad crlf\nand a good one\r";
evbuffer_add(evb_tmp, s, strlen(s));
evbuffer_validate(evb);
evbuffer_add_buffer(evb, evb_tmp);
evbuffer_validate(evb);
s = "\n\r";
evbuffer_add(evb_tmp, s, strlen(s));
evbuffer_validate(evb);
evbuffer_add_buffer(evb, evb_tmp);
evbuffer_validate(evb);
s = "\nMore\r";
evbuffer_add(evb_tmp, s, strlen(s));
evbuffer_validate(evb);
evbuffer_add_buffer(evb, evb_tmp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF_STRICT);
if (!cp || sz != strlen(cp) ||
strcmp(cp, " and a bad crlf\nand a good one"))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF_STRICT);
if (!cp || sz != strlen(cp) || strcmp(cp, ""))
goto done;
free(cp);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF_STRICT);
if (cp)
goto done;
evbuffer_validate(evb);
evbuffer_add(evb, "\n", 1);
evbuffer_validate(evb);
cp = evbuffer_readln(evb, &sz, EVBUFFER_EOL_CRLF_STRICT);
if (!cp || sz != strlen(cp) || strcmp(cp, "More"))
goto done;
evbuffer_validate(evb);
if (EVBUFFER_LENGTH(evb) != 0)
goto done;
@ -1115,6 +1212,36 @@ test_evbuffer_readln(void)
cleanup_test();
}
static void
test_evbuffer_iterative(void)
{
struct evbuffer *buf = evbuffer_new();
const char *abc = "abcdefghijklmnopqrstvuwxyzabcdefghijklmnopqrstvuwxyzabcdefghijklmnopqrstvuwxyzabcdefghijklmnopqrstvuwxyz";
int i, j, sum;
setup_test("Testing evbuffer() iterative: ");
sum = 0;
for (i = 0; i < 1000; ++i) {
for (j = 1; j < strlen(abc); ++j) {
char format[32];
snprintf(format, sizeof(format), "%%%d.%ds", j, j);
evbuffer_add_printf(buf, format, abc);
evbuffer_validate(buf);
sum += j;
}
}
if (sum == EVBUFFER_LENGTH(buf))
test_ok = 1;
evbuffer_free(buf);
cleanup_test();
}
static void
test_evbuffer_find(void)
{
@ -1129,8 +1256,11 @@ test_evbuffer_find(void)
/* make sure evbuffer_find doesn't match past the end of the buffer */
fprintf(stdout, "Testing evbuffer_find 1: ");
evbuffer_add(buf, (u_char*)test1, strlen(test1));
evbuffer_validate(buf);
evbuffer_drain(buf, strlen(test1));
evbuffer_validate(buf);
evbuffer_add(buf, (u_char*)test2, strlen(test2));
evbuffer_validate(buf);
p = evbuffer_find(buf, (u_char*)"\r\n", 2);
if (p == NULL) {
fprintf(stdout, "OK\n");
@ -1145,10 +1275,12 @@ test_evbuffer_find(void)
*/
fprintf(stdout, "Testing evbuffer_find 2: ");
evbuffer_drain(buf, strlen(test2));
evbuffer_validate(buf);
for (i = 0; i < EVBUFFER_INITIAL_LENGTH; ++i)
test3[i] = 'a';
test3[EVBUFFER_INITIAL_LENGTH - 1] = 'x';
evbuffer_add(buf, (u_char *)test3, EVBUFFER_INITIAL_LENGTH);
evbuffer_validate(buf);
p = evbuffer_find(buf, (u_char *)"xy", 2);
if (p == NULL) {
printf("OK\n");
@ -1718,6 +1850,7 @@ main (int argc, char **argv)
test_priorities(3);
test_evbuffer();
test_evbuffer_iterative();
test_evbuffer_readln();
test_evbuffer_find();