diff options
Diffstat (limited to 'src/qmail-smtpc/qmailr_tcpto.c')
| -rw-r--r-- | src/qmail-smtpc/qmailr_tcpto.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/qmail-smtpc/qmailr_tcpto.c b/src/qmail-smtpc/qmailr_tcpto.c new file mode 100644 index 0000000..fc8841b --- /dev/null +++ b/src/qmail-smtpc/qmailr_tcpto.c @@ -0,0 +1,167 @@ +/* ISC license. */ + +#include <stdint.h> +#include <string.h> +#include <unistd.h> +#include <stdlib.h> +#include <errno.h> + +#include <skalibs/uint32.h> +#include <skalibs/uint64.h> +#include <skalibs/allreadwrite.h> +#include <skalibs/cdb.h> +#include <skalibs/tai.h> +#include <skalibs/djbunix.h> + +#include <smtpd-starttls-proxy/config.h> +#include "qmailr.h" + +#include <skalibs/posixishard.h> + + +/* + tcpto implementation, should be compatible with qmail-tcpto. + Assumes the 4 unused bytes at the end of a record are there to + accommodate 64-bit time_t. Which we use. But qmail-tcpto does + not, so you should patch that before 2038. + Has ipv6 support, storing v6 records in a different file. + Unlike qmail's tcpto, we assume the records are sorted by IP. + This makes it easy to look for a record with bsearch. We + keep records sorted with every modification, and we aggressively + cut empty ones from the file. + For the match function, not sure what is faster between mmapping and + simple reading. Currently we mmap to save private/dirty RAM, but + that holds the lock longer; it should be ok because we switched to + a shared lock for this (unsure why djb didn't). +*/ + +static int memcmp4 (void const *a, void const *b) +{ + return memcmp(a, b, 4) ; +} + +static int memcmp16 (void const *a, void const *b) +{ + return memcmp(a, b, 16) ; +} + +int qmailr_tcpto_match (char const *ip, int is6) +{ + char const *file = is6 ? SMTPD_STARTTLS_PROXY_QMAIL_HOME "/run/qmail-remote/tcpto6" : SMTPD_STARTTLS_PROXY_QMAIL_HOME "/queue/lock/tcpto" ; + uint32_t iplen = is6 ? 16 : 4 ; + uint32_t width = iplen + 12 ; + int r = 0 ; + char const *p ; + cdb c ; /* XXX: not a cdb, we're just using the mmap wrapper */ + int fd = openc_read(file) ; + + if (fd == -1) return -1 ; + if (fd_lock(fd, 0, 0) == -1) goto err ; + if (!cdb_init_fromfd(&c, fd)) goto err ; + if (c.size % width) goto errproto ; + p = bsearch(ip, c.map, c.size / width, width, is6 ? &memcmp16 : &memcmp4) ; + if (p) + { + if (p[iplen] >= 2) + { + tai when ; + uint64_t x ; + uint64_unpack(p + iplen + 4, &x) ; + tai_u64(&when, x) ; + tai_sub(&when, tain_secp(&STAMP), &when) ; + r = tai_sec(&when) < ((60 + (getpid() & 31)) << 6) ; /* don't ask me, ask djb */ + } + } + cdb_free(&c) ; + fd_close(fd) ; + return r ; + + errproto: + errno = EPROTO ; + err: + fd_close(fd) ; + return -1 ; +} + +int qmailr_tcpto_update (char const *ip, int is6, int problem) +{ + char const *file = is6 ? SMTPD_STARTTLS_PROXY_QMAIL_HOME "/run/qmail-remote/tcpto6" : SMTPD_STARTTLS_PROXY_QMAIL_HOME "/queue/lock/tcpto" ; + uint32_t iplen = is6 ? 16 : 4 ; + uint32_t width = iplen + 12 ; + uint32_t n ; + char *p = 0 ; + struct stat st ; + int fdr ; + int fdw = openc_create(file) ; + + if (fdw == -1) return 0 ; + if (fd_lock(fdw, 1, 0) == -1) goto err ; + fdr = openc_read(file) ; + if (fdr == -1) goto err ; + if (fstat(fdr, &st) == -1) goto err0 ; + if (st.st_size % width) goto errproto ; + n = st.st_size / width ; + + { + char buf[(n+1) * width] ; /* relax, it won't bite */ + if (n) + { + if (allread(fdr, buf, st.st_size) < st.st_size) goto err0 ; + memset(buf + st.st_size, 0, width) ; + p = bsearch(ip, buf, n, width, is6 ? &memcmp16 : &memcmp4) ; + if (p) + { + if (problem) + { + tai when ; + uint64_t x ; + uint64_unpack(p + iplen + 4, &x) ; + tai_u64(&when, x) ; + tai_sub(&when, tain_secp(&STAMP), &when) ; + if (tai_sec(&when) < 120) p = 0 ; + else + { + if (++p[iplen] > 10) p[iplen] = 10 ; + x = tai_sec(tain_secp(&STAMP)) - TAI_MAGIC ; + uint64_pack(p + iplen + 4, x) ; + } + } + else p[iplen] = 0 ; + } + } + else if (problem) + { + uint64_t x = tai_sec(tain_secp(&STAMP)) - TAI_MAGIC ; + p = buf + n++ * width ; + memcpy(p, ip, iplen) ; + p[iplen] = 1 ; + memset(p + iplen + 1, 0, 3) ; + uint64_pack(p + iplen + 4, x) ; + } + fd_close(fdr) ; + + if (p) + { + for (uint32_t i = 0 ; i < n ; i++) + if (!buf[i * width + iplen]) + memcpy(buf + i * width, buf + --n * width, width) ; + if (n) + { + qsort(buf, n, width, is6 ? &memcmp16 : &memcmp4) ; + if (allwrite(fdw, buf, n * width) < n * width) goto err ; + } + if (ftruncate(fdw, n * width) == -1) goto err ; + } + } + + fd_close(fdw) ; + return 1 ; + + errproto: + errno = EPROTO ; + err0: + fd_close(fdr) ; + err: + fd_close(fdw) ; + return 0 ; +} |