Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: master
Fetching contributors…

Octocat-spinner-32-eaf2f5

Cannot retrieve contributors at this time

file 270 lines (228 sloc) 6.009 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269
#include "cache.h"
#include "credential.h"
#include "unix-socket.h"
#include "sigchain.h"

static const char *socket_path;

static void cleanup_socket(void)
{
if (socket_path)
unlink(socket_path);
}

static void cleanup_socket_on_signal(int sig)
{
cleanup_socket();
sigchain_pop(sig);
raise(sig);
}

struct credential_cache_entry {
struct credential item;
unsigned long expiration;
};
static struct credential_cache_entry *entries;
static int entries_nr;
static int entries_alloc;

static void cache_credential(struct credential *c, int timeout)
{
struct credential_cache_entry *e;

ALLOC_GROW(entries, entries_nr + 1, entries_alloc);
e = &entries[entries_nr++];

/* take ownership of pointers */
memcpy(&e->item, c, sizeof(*c));
memset(c, 0, sizeof(*c));
e->expiration = time(NULL) + timeout;
}

static struct credential_cache_entry *lookup_credential(const struct credential *c)
{
int i;
for (i = 0; i < entries_nr; i++) {
struct credential *e = &entries[i].item;
if (credential_match(c, e))
return &entries[i];
}
return NULL;
}

static void remove_credential(const struct credential *c)
{
struct credential_cache_entry *e;

e = lookup_credential(c);
if (e)
e->expiration = 0;
}

static int check_expirations(void)
{
static unsigned long wait_for_entry_until;
int i = 0;
unsigned long now = time(NULL);
unsigned long next = (unsigned long)-1;

/*
* Initially give the client 30 seconds to actually contact us
* and store a credential before we decide there's no point in
* keeping the daemon around.
*/
if (!wait_for_entry_until)
wait_for_entry_until = now + 30;

while (i < entries_nr) {
if (entries[i].expiration <= now) {
entries_nr--;
credential_clear(&entries[i].item);
if (i != entries_nr)
memcpy(&entries[i], &entries[entries_nr], sizeof(*entries));
/*
* Stick around 30 seconds in case a new credential
* shows up (e.g., because we just removed a failed
* one, and we will soon get the correct one).
*/
wait_for_entry_until = now + 30;
}
else {
if (entries[i].expiration < next)
next = entries[i].expiration;
i++;
}
}

if (!entries_nr) {
if (wait_for_entry_until <= now)
return 0;
next = wait_for_entry_until;
}

return next - now;
}

static int read_request(FILE *fh, struct credential *c,
struct strbuf *action, int *timeout) {
static struct strbuf item = STRBUF_INIT;
const char *p;

strbuf_getline(&item, fh, '\n');
p = skip_prefix(item.buf, "action=");
if (!p)
return error("client sent bogus action line: %s", item.buf);
strbuf_addstr(action, p);

strbuf_getline(&item, fh, '\n');
p = skip_prefix(item.buf, "timeout=");
if (!p)
return error("client sent bogus timeout line: %s", item.buf);
*timeout = atoi(p);

if (credential_read(c, fh) < 0)
return -1;
return 0;
}

static void serve_one_client(FILE *in, FILE *out)
{
struct credential c = CREDENTIAL_INIT;
struct strbuf action = STRBUF_INIT;
int timeout = -1;

if (read_request(in, &c, &action, &timeout) < 0)
/* ignore error */ ;
else if (!strcmp(action.buf, "get")) {
struct credential_cache_entry *e = lookup_credential(&c);
if (e) {
fprintf(out, "username=%s\n", e->item.username);
fprintf(out, "password=%s\n", e->item.password);
}
}
else if (!strcmp(action.buf, "exit"))
exit(0);
else if (!strcmp(action.buf, "erase"))
remove_credential(&c);
else if (!strcmp(action.buf, "store")) {
if (timeout < 0)
warning("cache client didn't specify a timeout");
else if (!c.username || !c.password)
warning("cache client gave us a partial credential");
else {
remove_credential(&c);
cache_credential(&c, timeout);
}
}
else
warning("cache client sent unknown action: %s", action.buf);

credential_clear(&c);
strbuf_release(&action);
}

static int serve_cache_loop(int fd)
{
struct pollfd pfd;
unsigned long wakeup;

wakeup = check_expirations();
if (!wakeup)
return 0;

pfd.fd = fd;
pfd.events = POLLIN;
if (poll(&pfd, 1, 1000 * wakeup) < 0) {
if (errno != EINTR)
die_errno("poll failed");
return 1;
}

if (pfd.revents & POLLIN) {
int client, client2;
FILE *in, *out;

client = accept(fd, NULL, NULL);
if (client < 0) {
warning("accept failed: %s", strerror(errno));
return 1;
}
client2 = dup(client);
if (client2 < 0) {
warning("dup failed: %s", strerror(errno));
close(client);
return 1;
}

in = xfdopen(client, "r");
out = xfdopen(client2, "w");
serve_one_client(in, out);
fclose(in);
fclose(out);
}
return 1;
}

static void serve_cache(const char *socket_path)
{
int fd;

fd = unix_stream_listen(socket_path);
if (fd < 0)
die_errno("unable to bind to '%s'", socket_path);

printf("ok\n");
fclose(stdout);

while (serve_cache_loop(fd))
; /* nothing */

close(fd);
unlink(socket_path);
}

static const char permissions_advice[] =
"The permissions on your socket directory are too loose; other\n"
"users may be able to read your cached credentials. Consider running:\n"
"\n"
" chmod 0700 %s";
static void check_socket_directory(const char *path)
{
struct stat st;
char *path_copy = xstrdup(path);
char *dir = dirname(path_copy);

if (!stat(dir, &st)) {
if (st.st_mode & 077)
die(permissions_advice, dir);
free(path_copy);
return;
}

/*
* We must be sure to create the directory with the correct mode,
* not just chmod it after the fact; otherwise, there is a race
* condition in which somebody can chdir to it, sleep, then try to open
* our protected socket.
*/
if (safe_create_leading_directories_const(dir) < 0)
die_errno("unable to create directories for '%s'", dir);
if (mkdir(dir, 0700) < 0)
die_errno("unable to mkdir '%s'", dir);
free(path_copy);
}

int main(int argc, const char **argv)
{
socket_path = argv[1];

if (!socket_path)
die("usage: git-credential-cache--daemon <socket_path>");
check_socket_directory(socket_path);

atexit(cleanup_socket);
sigchain_push_common(cleanup_socket_on_signal);

serve_cache(socket_path);

return 0;
}
Something went wrong with that request. Please try again.