git/http.c
Shawn O. Pearce 3278cd0a39 Properly cleanup in http_cleanup so builtin-fetch does not segfault
Junio and I both noticed that the new builtin-fetch was segfaulting
immediately on http/https/ftp style URLs (those that went through
libcurl and the commit walker).  Although the builtin-fetch changes
in this area were really just minor refactorings there was one major
change made: we invoked http_init(), http_cleanup() then http_init()
again in the same process.

When we call curl_easy_cleanup() on each active_request_slot we
are telling libcurl we did not want that buffer to be used again.
Unfortunately we did not also deallocate the active_request_slot
itself nor did we NULL out active_queue_head.  This lead us to
attempt to reuse these cleaned up libcurl handles when we later tried
to invoke http_init() a second time to reactivate the curl library.
The next file get operation then immediately segfaulted on most
versions of libcurl.

Properly freeing our own buffers and clearing the list causes us to
reinitialize the curl buffers again if/when we need to use libcurl
from within this same process.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-19 03:22:31 -07:00

551 lines
12 KiB
C

#include "http.h"
int data_received;
int active_requests = 0;
#ifdef USE_CURL_MULTI
int max_requests = -1;
CURLM *curlm;
#endif
#ifndef NO_CURL_EASY_DUPHANDLE
CURL *curl_default;
#endif
char curl_errorstr[CURL_ERROR_SIZE];
int curl_ssl_verify = -1;
char *ssl_cert = NULL;
#if LIBCURL_VERSION_NUM >= 0x070902
char *ssl_key = NULL;
#endif
#if LIBCURL_VERSION_NUM >= 0x070908
char *ssl_capath = NULL;
#endif
char *ssl_cainfo = NULL;
long curl_low_speed_limit = -1;
long curl_low_speed_time = -1;
int curl_ftp_no_epsv = 0;
struct curl_slist *pragma_header;
struct active_request_slot *active_queue_head = NULL;
size_t fread_buffer(void *ptr, size_t eltsize, size_t nmemb,
struct buffer *buffer)
{
size_t size = eltsize * nmemb;
if (size > buffer->size - buffer->posn)
size = buffer->size - buffer->posn;
memcpy(ptr, (char *) buffer->buffer + buffer->posn, size);
buffer->posn += size;
return size;
}
size_t fwrite_buffer(const void *ptr, size_t eltsize,
size_t nmemb, struct buffer *buffer)
{
size_t size = eltsize * nmemb;
if (size > buffer->size - buffer->posn) {
buffer->size = buffer->size * 3 / 2;
if (buffer->size < buffer->posn + size)
buffer->size = buffer->posn + size;
buffer->buffer = xrealloc(buffer->buffer, buffer->size);
}
memcpy((char *) buffer->buffer + buffer->posn, ptr, size);
buffer->posn += size;
data_received++;
return size;
}
size_t fwrite_null(const void *ptr, size_t eltsize,
size_t nmemb, struct buffer *buffer)
{
data_received++;
return eltsize * nmemb;
}
static void finish_active_slot(struct active_request_slot *slot);
#ifdef USE_CURL_MULTI
static void process_curl_messages(void)
{
int num_messages;
struct active_request_slot *slot;
CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
while (curl_message != NULL) {
if (curl_message->msg == CURLMSG_DONE) {
int curl_result = curl_message->data.result;
slot = active_queue_head;
while (slot != NULL &&
slot->curl != curl_message->easy_handle)
slot = slot->next;
if (slot != NULL) {
curl_multi_remove_handle(curlm, slot->curl);
slot->curl_result = curl_result;
finish_active_slot(slot);
} else {
fprintf(stderr, "Received DONE message for unknown request!\n");
}
} else {
fprintf(stderr, "Unknown CURL message received: %d\n",
(int)curl_message->msg);
}
curl_message = curl_multi_info_read(curlm, &num_messages);
}
}
#endif
static int http_options(const char *var, const char *value)
{
if (!strcmp("http.sslverify", var)) {
if (curl_ssl_verify == -1) {
curl_ssl_verify = git_config_bool(var, value);
}
return 0;
}
if (!strcmp("http.sslcert", var)) {
if (ssl_cert == NULL) {
ssl_cert = xmalloc(strlen(value)+1);
strcpy(ssl_cert, value);
}
return 0;
}
#if LIBCURL_VERSION_NUM >= 0x070902
if (!strcmp("http.sslkey", var)) {
if (ssl_key == NULL) {
ssl_key = xmalloc(strlen(value)+1);
strcpy(ssl_key, value);
}
return 0;
}
#endif
#if LIBCURL_VERSION_NUM >= 0x070908
if (!strcmp("http.sslcapath", var)) {
if (ssl_capath == NULL) {
ssl_capath = xmalloc(strlen(value)+1);
strcpy(ssl_capath, value);
}
return 0;
}
#endif
if (!strcmp("http.sslcainfo", var)) {
if (ssl_cainfo == NULL) {
ssl_cainfo = xmalloc(strlen(value)+1);
strcpy(ssl_cainfo, value);
}
return 0;
}
#ifdef USE_CURL_MULTI
if (!strcmp("http.maxrequests", var)) {
if (max_requests == -1)
max_requests = git_config_int(var, value);
return 0;
}
#endif
if (!strcmp("http.lowspeedlimit", var)) {
if (curl_low_speed_limit == -1)
curl_low_speed_limit = (long)git_config_int(var, value);
return 0;
}
if (!strcmp("http.lowspeedtime", var)) {
if (curl_low_speed_time == -1)
curl_low_speed_time = (long)git_config_int(var, value);
return 0;
}
if (!strcmp("http.noepsv", var)) {
curl_ftp_no_epsv = git_config_bool(var, value);
return 0;
}
/* Fall back on the default ones */
return git_default_config(var, value);
}
static CURL* get_curl_handle(void)
{
CURL* result = curl_easy_init();
curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
#if LIBCURL_VERSION_NUM >= 0x070907
curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
#endif
if (ssl_cert != NULL)
curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
#if LIBCURL_VERSION_NUM >= 0x070902
if (ssl_key != NULL)
curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
#endif
#if LIBCURL_VERSION_NUM >= 0x070908
if (ssl_capath != NULL)
curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
#endif
if (ssl_cainfo != NULL)
curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
curl_easy_setopt(result, CURLOPT_FAILONERROR, 1);
if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
curl_low_speed_limit);
curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
curl_low_speed_time);
}
curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
if (getenv("GIT_CURL_VERBOSE"))
curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
curl_easy_setopt(result, CURLOPT_USERAGENT, GIT_USER_AGENT);
if (curl_ftp_no_epsv)
curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
return result;
}
void http_init(void)
{
char *low_speed_limit;
char *low_speed_time;
curl_global_init(CURL_GLOBAL_ALL);
pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
#ifdef USE_CURL_MULTI
{
char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
if (http_max_requests != NULL)
max_requests = atoi(http_max_requests);
}
curlm = curl_multi_init();
if (curlm == NULL) {
fprintf(stderr, "Error creating curl multi handle.\n");
exit(1);
}
#endif
if (getenv("GIT_SSL_NO_VERIFY"))
curl_ssl_verify = 0;
ssl_cert = getenv("GIT_SSL_CERT");
#if LIBCURL_VERSION_NUM >= 0x070902
ssl_key = getenv("GIT_SSL_KEY");
#endif
#if LIBCURL_VERSION_NUM >= 0x070908
ssl_capath = getenv("GIT_SSL_CAPATH");
#endif
ssl_cainfo = getenv("GIT_SSL_CAINFO");
low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
if (low_speed_limit != NULL)
curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
if (low_speed_time != NULL)
curl_low_speed_time = strtol(low_speed_time, NULL, 10);
git_config(http_options);
if (curl_ssl_verify == -1)
curl_ssl_verify = 1;
#ifdef USE_CURL_MULTI
if (max_requests < 1)
max_requests = DEFAULT_MAX_REQUESTS;
#endif
if (getenv("GIT_CURL_FTP_NO_EPSV"))
curl_ftp_no_epsv = 1;
#ifndef NO_CURL_EASY_DUPHANDLE
curl_default = get_curl_handle();
#endif
}
void http_cleanup(void)
{
struct active_request_slot *slot = active_queue_head;
#ifdef USE_CURL_MULTI
char *wait_url;
#endif
while (slot != NULL) {
struct active_request_slot *next = slot->next;
#ifdef USE_CURL_MULTI
if (slot->in_use) {
curl_easy_getinfo(slot->curl,
CURLINFO_EFFECTIVE_URL,
&wait_url);
fprintf(stderr, "Waiting for %s\n", wait_url);
run_active_slot(slot);
}
#endif
if (slot->curl != NULL)
curl_easy_cleanup(slot->curl);
free(slot);
slot = next;
}
active_queue_head = NULL;
#ifndef NO_CURL_EASY_DUPHANDLE
curl_easy_cleanup(curl_default);
#endif
#ifdef USE_CURL_MULTI
curl_multi_cleanup(curlm);
#endif
curl_global_cleanup();
curl_slist_free_all(pragma_header);
pragma_header = NULL;
}
struct active_request_slot *get_active_slot(void)
{
struct active_request_slot *slot = active_queue_head;
struct active_request_slot *newslot;
#ifdef USE_CURL_MULTI
int num_transfers;
/* Wait for a slot to open up if the queue is full */
while (active_requests >= max_requests) {
curl_multi_perform(curlm, &num_transfers);
if (num_transfers < active_requests) {
process_curl_messages();
}
}
#endif
while (slot != NULL && slot->in_use) {
slot = slot->next;
}
if (slot == NULL) {
newslot = xmalloc(sizeof(*newslot));
newslot->curl = NULL;
newslot->in_use = 0;
newslot->next = NULL;
slot = active_queue_head;
if (slot == NULL) {
active_queue_head = newslot;
} else {
while (slot->next != NULL) {
slot = slot->next;
}
slot->next = newslot;
}
slot = newslot;
}
if (slot->curl == NULL) {
#ifdef NO_CURL_EASY_DUPHANDLE
slot->curl = get_curl_handle();
#else
slot->curl = curl_easy_duphandle(curl_default);
#endif
}
active_requests++;
slot->in_use = 1;
slot->local = NULL;
slot->results = NULL;
slot->finished = NULL;
slot->callback_data = NULL;
slot->callback_func = NULL;
curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
return slot;
}
int start_active_slot(struct active_request_slot *slot)
{
#ifdef USE_CURL_MULTI
CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
int num_transfers;
if (curlm_result != CURLM_OK &&
curlm_result != CURLM_CALL_MULTI_PERFORM) {
active_requests--;
slot->in_use = 0;
return 0;
}
/*
* We know there must be something to do, since we just added
* something.
*/
curl_multi_perform(curlm, &num_transfers);
#endif
return 1;
}
#ifdef USE_CURL_MULTI
struct fill_chain {
void *data;
int (*fill)(void *);
struct fill_chain *next;
};
static struct fill_chain *fill_cfg = NULL;
void add_fill_function(void *data, int (*fill)(void *))
{
struct fill_chain *new = malloc(sizeof(*new));
struct fill_chain **linkp = &fill_cfg;
new->data = data;
new->fill = fill;
new->next = NULL;
while (*linkp)
linkp = &(*linkp)->next;
*linkp = new;
}
void fill_active_slots(void)
{
struct active_request_slot *slot = active_queue_head;
while (active_requests < max_requests) {
struct fill_chain *fill;
for (fill = fill_cfg; fill; fill = fill->next)
if (fill->fill(fill->data))
break;
if (!fill)
break;
}
while (slot != NULL) {
if (!slot->in_use && slot->curl != NULL) {
curl_easy_cleanup(slot->curl);
slot->curl = NULL;
}
slot = slot->next;
}
}
void step_active_slots(void)
{
int num_transfers;
CURLMcode curlm_result;
do {
curlm_result = curl_multi_perform(curlm, &num_transfers);
} while (curlm_result == CURLM_CALL_MULTI_PERFORM);
if (num_transfers < active_requests) {
process_curl_messages();
fill_active_slots();
}
}
#endif
void run_active_slot(struct active_request_slot *slot)
{
#ifdef USE_CURL_MULTI
long last_pos = 0;
long current_pos;
fd_set readfds;
fd_set writefds;
fd_set excfds;
int max_fd;
struct timeval select_timeout;
int finished = 0;
slot->finished = &finished;
while (!finished) {
data_received = 0;
step_active_slots();
if (!data_received && slot->local != NULL) {
current_pos = ftell(slot->local);
if (current_pos > last_pos)
data_received++;
last_pos = current_pos;
}
if (slot->in_use && !data_received) {
max_fd = 0;
FD_ZERO(&readfds);
FD_ZERO(&writefds);
FD_ZERO(&excfds);
select_timeout.tv_sec = 0;
select_timeout.tv_usec = 50000;
select(max_fd, &readfds, &writefds,
&excfds, &select_timeout);
}
}
#else
while (slot->in_use) {
slot->curl_result = curl_easy_perform(slot->curl);
finish_active_slot(slot);
}
#endif
}
static void closedown_active_slot(struct active_request_slot *slot)
{
active_requests--;
slot->in_use = 0;
}
void release_active_slot(struct active_request_slot *slot)
{
closedown_active_slot(slot);
if (slot->curl) {
#ifdef USE_CURL_MULTI
curl_multi_remove_handle(curlm, slot->curl);
#endif
curl_easy_cleanup(slot->curl);
slot->curl = NULL;
}
#ifdef USE_CURL_MULTI
fill_active_slots();
#endif
}
static void finish_active_slot(struct active_request_slot *slot)
{
closedown_active_slot(slot);
curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
if (slot->finished != NULL)
(*slot->finished) = 1;
/* Store slot results so they can be read after the slot is reused */
if (slot->results != NULL) {
slot->results->curl_result = slot->curl_result;
slot->results->http_code = slot->http_code;
}
/* Run callback if appropriate */
if (slot->callback_func != NULL) {
slot->callback_func(slot->callback_data);
}
}
void finish_all_active_slots(void)
{
struct active_request_slot *slot = active_queue_head;
while (slot != NULL)
if (slot->in_use) {
run_active_slot(slot);
slot = active_queue_head;
} else {
slot = slot->next;
}
}