mirror of
https://github.com/pi-hole/dnsmasq.git
synced 2025-12-19 10:18:25 +00:00
Tidy up pipe-to-parent code in DNS TCP path.
This commit is contained in:
Simon Kelley
281
src/cache.c
281
src/cache.c
@@ -799,14 +799,16 @@ void cache_end_insert(void)
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char *name = cache_get_name(new_chain);
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ssize_t m = strlen(name);
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unsigned int flags = new_chain->flags;
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unsigned char op = PIPE_OP_RR;
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#ifdef HAVE_DNSSEC
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u16 class = new_chain->uid;
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#endif
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read_write(daemon->pipe_to_parent, &op, sizeof(op), RW_WRITE);
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read_write(daemon->pipe_to_parent, (unsigned char *)&m, sizeof(m), RW_WRITE);
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read_write(daemon->pipe_to_parent, (unsigned char *)name, m, RW_WRITE);
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read_write(daemon->pipe_to_parent, (unsigned char *)&new_chain->ttd, sizeof(new_chain->ttd), RW_WRITE);
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read_write(daemon->pipe_to_parent, (unsigned char *)&flags, sizeof(flags), RW_WRITE);
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read_write(daemon->pipe_to_parent, (unsigned char *)&flags, sizeof(flags), RW_WRITE);
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read_write(daemon->pipe_to_parent, (unsigned char *)&new_chain->addr, sizeof(new_chain->addr), RW_WRITE);
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if (flags & F_RR)
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@@ -838,27 +840,29 @@ void cache_end_insert(void)
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/* signal end of cache insert in master process */
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if (daemon->pipe_to_parent != -1)
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{
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ssize_t m = -1;
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read_write(daemon->pipe_to_parent, (unsigned char *)&m, sizeof(m), RW_WRITE);
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#ifdef HAVE_DNSSEC
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/* Sneak out possibly updated crypto HWM values. */
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read_write(daemon->pipe_to_parent,
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(unsigned char *)&daemon->metrics[METRIC_CRYPTO_HWM],
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sizeof(daemon->metrics[METRIC_CRYPTO_HWM]), RW_WRITE);
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read_write(daemon->pipe_to_parent,
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(unsigned char *)&daemon->metrics[METRIC_SIG_FAIL_HWM],
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sizeof(daemon->metrics[METRIC_SIG_FAIL_HWM]), RW_WRITE);
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read_write(daemon->pipe_to_parent,
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(unsigned char *)&daemon->metrics[METRIC_WORK_HWM],
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sizeof(daemon->metrics[METRIC_WORK_HWM]), RW_WRITE);
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#endif
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unsigned char op = PIPE_OP_END;
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read_write(daemon->pipe_to_parent, &op, sizeof(op), RW_WRITE);
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}
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new_chain = NULL;
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}
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#ifdef HAVE_DNSSEC
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void cache_update_hwm(void)
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{
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/* Sneak out possibly updated crypto HWM values. */
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unsigned char op = PIPE_OP_STATS;
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read_write(daemon->pipe_to_parent, &op, sizeof(op), RW_WRITE);
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read_write(daemon->pipe_to_parent,
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(unsigned char *)&daemon->metrics[METRIC_CRYPTO_HWM],
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sizeof(daemon->metrics[METRIC_CRYPTO_HWM]), RW_WRITE);
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read_write(daemon->pipe_to_parent,
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(unsigned char *)&daemon->metrics[METRIC_SIG_FAIL_HWM],
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sizeof(daemon->metrics[METRIC_SIG_FAIL_HWM]), RW_WRITE);
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read_write(daemon->pipe_to_parent,
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(unsigned char *)&daemon->metrics[METRIC_WORK_HWM],
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sizeof(daemon->metrics[METRIC_WORK_HWM]), RW_WRITE);
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}
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#endif
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/* A marshalled cache entry arrives on fd, read, unmarshall and insert into cache of master process. */
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int cache_recv_insert(time_t now, int fd)
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@@ -869,139 +873,150 @@ int cache_recv_insert(time_t now, int fd)
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time_t ttd;
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unsigned int flags;
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struct crec *crecp = NULL;
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unsigned char op;
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cache_start_insert();
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while (1)
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{
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if (!read_write(fd, (unsigned char *)&m, sizeof(m), RW_READ))
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if (!read_write(fd, &op, sizeof(op), RW_READ))
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return 0;
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if (m == -1)
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switch (op)
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{
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#ifdef HAVE_DNSSEC
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/* Sneak in possibly updated crypto HWM. */
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unsigned int val;
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if (!read_write(fd, (unsigned char *)&val, sizeof(val), RW_READ))
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return 0;
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if (val > daemon->metrics[METRIC_CRYPTO_HWM])
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daemon->metrics[METRIC_CRYPTO_HWM] = val;
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if (!read_write(fd, (unsigned char *)&val, sizeof(val), RW_READ))
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return 0;
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if (val > daemon->metrics[METRIC_SIG_FAIL_HWM])
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daemon->metrics[METRIC_SIG_FAIL_HWM] = val;
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if (!read_write(fd, (unsigned char *)&val, sizeof(val), RW_READ))
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return 0;
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if (val > daemon->metrics[METRIC_WORK_HWM])
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daemon->metrics[METRIC_WORK_HWM] = val;
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#endif
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case PIPE_OP_END:
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cache_end_insert();
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return 1;
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}
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#ifdef HAVE_DNSSEC
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/* UDP validation moved to TCP to avoid truncation.
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Restart UDP validation process with the returned result. */
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if (m == -2)
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{
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int status, uid, keycount, validatecount;
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int *keycountp, *validatecountp;
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size_t ret_len;
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case PIPE_OP_STATS:
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{
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/* Sneak in possibly updated crypto HWM. */
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unsigned int val;
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if (!read_write(fd, (unsigned char *)&val, sizeof(val), RW_READ))
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return 0;
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if (val > daemon->metrics[METRIC_CRYPTO_HWM])
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daemon->metrics[METRIC_CRYPTO_HWM] = val;
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if (!read_write(fd, (unsigned char *)&val, sizeof(val), RW_READ))
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return 0;
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if (val > daemon->metrics[METRIC_SIG_FAIL_HWM])
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daemon->metrics[METRIC_SIG_FAIL_HWM] = val;
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if (!read_write(fd, (unsigned char *)&val, sizeof(val), RW_READ))
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return 0;
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if (val > daemon->metrics[METRIC_WORK_HWM])
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daemon->metrics[METRIC_WORK_HWM] = val;
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return 1;
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}
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struct frec *forward;
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if (!read_write(fd, (unsigned char *)&status, sizeof(status), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&ret_len, sizeof(ret_len), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)daemon->packet, ret_len, RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&forward, sizeof(forward), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&uid, sizeof(uid), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&keycount, sizeof(keycount), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&keycountp, sizeof(keycountp), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&validatecount, sizeof(validatecount), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&validatecountp, sizeof(validatecountp), RW_READ))
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return 0;
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/* There's a tiny chance that the frec may have been freed
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and reused before the TCP process returns. Detect that with
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the uid field which is unique modulo 2^32 for each use. */
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if (uid == forward->uid)
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{
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/* repatriate the work counters from the child process. */
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*keycountp = keycount;
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*validatecountp = validatecount;
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if (!forward->dependent)
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return_reply(now, forward, (struct dns_header *)daemon->packet, ret_len, status);
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else
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pop_and_retry_query(forward, status, now);
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}
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return 1;
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}
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case PIPE_OP_RESULT:
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{
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/* UDP validation moved to TCP to avoid truncation.
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Restart UDP validation process with the returned result. */
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int status, uid, keycount, validatecount;
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int *keycountp, *validatecountp;
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size_t ret_len;
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struct frec *forward;
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if (!read_write(fd, (unsigned char *)&status, sizeof(status), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&ret_len, sizeof(ret_len), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)daemon->packet, ret_len, RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&forward, sizeof(forward), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&uid, sizeof(uid), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&keycount, sizeof(keycount), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&keycountp, sizeof(keycountp), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&validatecount, sizeof(validatecount), RW_READ))
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return 0;
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if (!read_write(fd, (unsigned char *)&validatecountp, sizeof(validatecountp), RW_READ))
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return 0;
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/* There's a tiny chance that the frec may have been freed
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and reused before the TCP process returns. Detect that with
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the uid field which is unique modulo 2^32 for each use. */
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if (uid == forward->uid)
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{
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/* repatriate the work counters from the child process. */
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*keycountp = keycount;
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*validatecountp = validatecount;
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if (!forward->dependent)
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return_reply(now, forward, (struct dns_header *)daemon->packet, ret_len, status);
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else
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pop_and_retry_query(forward, status, now);
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}
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return 1;
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}
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#endif
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if (!read_write(fd, (unsigned char *)daemon->namebuff, m, RW_READ) ||
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!read_write(fd, (unsigned char *)&ttd, sizeof(ttd), RW_READ) ||
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!read_write(fd, (unsigned char *)&flags, sizeof(flags), RW_READ) ||
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!read_write(fd, (unsigned char *)&addr, sizeof(addr), RW_READ))
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return 0;
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daemon->namebuff[m] = 0;
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ttl = difftime(ttd, now);
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if (flags & F_CNAME)
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{
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struct crec *newc = really_insert(daemon->namebuff, NULL, C_IN, now, ttl, flags);
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/* This relies on the fact that the target of a CNAME immediately precedes
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it because of the order of extraction in extract_addresses, and
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the order reversal on the new_chain. */
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if (newc)
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case PIPE_OP_RR:
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if (!read_write(fd, (unsigned char *)&m, sizeof(m), RW_READ) ||
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!read_write(fd, (unsigned char *)daemon->namebuff, m, RW_READ) ||
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!read_write(fd, (unsigned char *)&ttd, sizeof(ttd), RW_READ) ||
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!read_write(fd, (unsigned char *)&flags, sizeof(flags), RW_READ) ||
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!read_write(fd, (unsigned char *)&addr, sizeof(addr), RW_READ))
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return 0;
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daemon->namebuff[m] = 0;
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ttl = difftime(ttd, now);
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if (flags & F_CNAME)
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{
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newc->addr.cname.is_name_ptr = 0;
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if (!crecp)
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newc->addr.cname.target.cache = NULL;
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else
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struct crec *newc = really_insert(daemon->namebuff, NULL, C_IN, now, ttl, flags);
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/* This relies on the fact that the target of a CNAME immediately precedes
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it because of the order of extraction in extract_addresses, and
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the order reversal on the new_chain. */
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if (newc)
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{
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next_uid(crecp);
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newc->addr.cname.target.cache = crecp;
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newc->addr.cname.uid = crecp->uid;
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newc->addr.cname.is_name_ptr = 0;
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if (!crecp)
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newc->addr.cname.target.cache = NULL;
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else
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{
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next_uid(crecp);
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newc->addr.cname.target.cache = crecp;
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newc->addr.cname.uid = crecp->uid;
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}
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}
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}
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}
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else
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{
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unsigned short class = C_IN;
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if ((flags & F_RR) && !(flags & F_NEG) && (flags & F_KEYTAG)
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&& !(addr.rrblock.rrdata = blockdata_read(fd, addr.rrblock.datalen)))
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return 0;
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else
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{
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unsigned short class = C_IN;
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if ((flags & F_RR) && !(flags & F_NEG) && (flags & F_KEYTAG)
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&& !(addr.rrblock.rrdata = blockdata_read(fd, addr.rrblock.datalen)))
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return 0;
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#ifdef HAVE_DNSSEC
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if (flags & F_DNSKEY)
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{
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if (!read_write(fd, (unsigned char *)&class, sizeof(class), RW_READ) ||
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!(addr.key.keydata = blockdata_read(fd, addr.key.keylen)))
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return 0;
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}
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else if (flags & F_DS)
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{
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if (!read_write(fd, (unsigned char *)&class, sizeof(class), RW_READ) ||
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(!(flags & F_NEG) && !(addr.key.keydata = blockdata_read(fd, addr.key.keylen))))
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return 0;
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}
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if (flags & F_DNSKEY)
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{
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if (!read_write(fd, (unsigned char *)&class, sizeof(class), RW_READ) ||
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!(addr.key.keydata = blockdata_read(fd, addr.key.keylen)))
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return 0;
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}
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else if (flags & F_DS)
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{
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if (!read_write(fd, (unsigned char *)&class, sizeof(class), RW_READ) ||
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(!(flags & F_NEG) && !(addr.key.keydata = blockdata_read(fd, addr.key.keylen))))
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return 0;
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}
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#endif
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crecp = really_insert(daemon->namebuff, &addr, class, now, ttl, flags);
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crecp = really_insert(daemon->namebuff, &addr, class, now, ttl, flags);
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}
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/* loop reading RRs, since we don't want to go back to the poll() loop
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and start processing other queries which might pollute the insertion
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chain. The child will never block between the first OP_RR and the OP_END */
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continue;
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}
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}
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}
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