37
37
/* TLS_SESS_STATE *context;
39
/* This module enforces timeouts on non-blocking I/O while
40
/* performing TLS handshake or input/output operations.
39
/* This module enforces VSTREAM-style timeouts on non-blocking
40
/* I/O while performing TLS handshake or input/output operations.
42
42
/* The Postfix VSTREAM read/write routines invoke the
43
43
/* tls_bio_read/write routines to send and receive plain-text
75
75
/* TLS session state.
77
/* The result value is -1 in case of a network read/write
78
/* error, otherwise it is the result value of the TLS operation.
77
/* A result value > 0 means successful completion.
79
/* A result value < 0 means that the requested operation did
80
/* not complete due to TLS protocol failure, system call
81
/* failure, or for any reason described under "in addition"
84
/* A result value of 0 from tls_bio_shutdown() means that the
85
/* operation is in progress. A result value of 0 from other
86
/* tls_bio_ops(3) operations means that the remote party either
87
/* closed the network connection or that it sent a TLS shutdown
90
/* Upon return from the tls_bio_ops(3) routines the global
91
/* errno value is non-zero when the requested operation did not
92
/* complete due to system call failure.
94
/* In addition, the result value is set to -1, and the global
95
/* errno value is set to ETIMEDOUT, when some network read/write
96
/* operation did not complete within the time limit.
103
121
/* System library. */
105
123
#include <sys_defs.h>
124
#include <sys/time.h>
128
#define timersub(a, b, res) do { \
129
(res)->tv_sec = (a)->tv_sec - (b)->tv_sec; \
130
(res)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
131
if ((res)->tv_usec < 0) { \
133
(res)->tv_usec += 1000000; \
127
158
const char *myname = "tls_bio";
162
struct timeval time_left; /* amount of time left */
163
struct timeval time_deadline; /* time of deadline */
164
struct timeval time_now; /* time after SSL_mumble() call */
167
* Compensation for interface mis-match: With VSTREAMs, timeout <= 0
168
* means wait forever; with the read/write_wait() calls below, we need to
169
* specify timeout < 0 instead.
171
* Safety: no time limit means no deadline.
179
* Deadline management is simpler than with VSTREAMs, because we don't
180
* need to decrement a per-stream time limit. We just work within the
181
* budget that is available for this tls_bio() call.
185
vstream_fstat(TLScontext->stream, VSTREAM_FLAG_DEADLINE);
186
if (enable_deadline) {
187
GETTIMEOFDAY(&time_deadline);
188
time_deadline.tv_sec += timeout;
134
193
* If necessary, retry the SSL handshake or read/write operation after
135
194
* handling any pending network I/O.
137
for (done = 0; done == 0; /* void */ ) {
139
198
status = hsfunc(TLScontext->con);
243
* Correspondence between SSL_ERROR_* error codes and tls_bio_(read,
244
* write, accept, connect, shutdown) return values (for brevity:
247
* SSL_ERROR_NONE corresponds with retval > 0. With SSL_(read, write)
248
* this is the number of plaintext bytes sent or received. With
249
* SSL_(accept, connect, shutdown) this means that the operation was
250
* completed successfully.
252
* SSL_ERROR_WANT_(WRITE, READ) start a new loop iteration, or force
253
* (retval = -1, errno = ETIMEDOUT) when the time limit is exceeded.
255
* All other SSL_ERROR_* cases correspond with retval <= 0. With
256
* SSL_(read, write, accept, connect) retval == 0 means that the
257
* remote party either closed the network connection or that it
258
* requested TLS shutdown; with SSL_shutdown() retval == 0 means that
259
* our own shutdown request is in progress. With all operations
260
* retval < 0 means that there was an error. In the latter case,
261
* SSL_ERROR_SYSCALL means that error details are returned via the
184
264
* Find out if we must retry the operation and/or if there is pending
189
269
* anomaly here and repeat the call.
192
case SSL_ERROR_NONE: /* success */
196
272
case SSL_ERROR_WANT_WRITE:
197
if (write_wait(fd, timeout) < 0)
198
return (-1); /* timeout error */
200
273
case SSL_ERROR_WANT_READ:
201
if (read_wait(fd, timeout) < 0)
202
return (-1); /* timeout error */
274
if (enable_deadline) {
275
GETTIMEOFDAY(&time_now);
276
timersub(&time_deadline, &time_now, &time_left);
277
timeout = time_left.tv_sec + (time_left.tv_usec > 0);
283
if (err == SSL_ERROR_WANT_WRITE) {
284
if (write_wait(fd, timeout) < 0)
285
return (-1); /* timeout error */
287
if (read_wait(fd, timeout) < 0)
288
return (-1); /* timeout error */
293
* Unhandled cases: SSL_ERROR_WANT_(ACCEPT, CONNECT, X509_LOOKUP)
294
* etc. Historically, Postfix silently treated these as ordinary
295
* I/O errors so we don't really know how common they are. For
296
* now, we just log a warning.
299
msg_warn("%s: unexpected SSL_ERROR code %d", myname, err);
206
303
* With tls_timed_read() and tls_timed_write() the caller is the
207
304
* VSTREAM library module which is unaware of TLS, so we log the
208
305
* TLS error stack here. In a better world, each VSTREAM I/O
added
removed
src/tls/tls_bio_ops.c
