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Diffstat (limited to 'src/qmail-remote/smtproutes.c')
| -rw-r--r-- | src/qmail-remote/smtproutes.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/src/qmail-remote/smtproutes.c b/src/qmail-remote/smtproutes.c new file mode 100644 index 0000000..7467031 --- /dev/null +++ b/src/qmail-remote/smtproutes.c @@ -0,0 +1,240 @@ +/* ISC license. */ + +#include <skalibs/bsdsnowflake.h> + +#include <string.h> +#include <stdint.h> +#include <unistd.h> +#include <stdlib.h> +#include <errno.h> +#include <stdio.h> + +#include <skalibs/stat.h> +#include <skalibs/posixplz.h> +#include <skalibs/uint16.h> +#include <skalibs/buffer.h> +#include <skalibs/cdb.h> +#include <skalibs/cdbmake.h> +#include <skalibs/stralloc.h> +#include <skalibs/djbtime.h> +#include <skalibs/djbunix.h> + +#include <smtpd-starttls-proxy/config.h> +#include "qmailr.h" +#include "qmail-remote.h" + + +/* + qmail-remote uses a "constmap" for smtproutes, which is + basically a cdb in RAM. Every instance of qmail-remote + parses control/smtproutes to make the constmap. + We replace it with a real cdb, stored in the filesystem. + It saves CPU (N-1 instances of qmail-remote use the cdb + directly) and RAM (the cdb is read-only and shared). + The cdb is updated whenever control/smtproutes is newer. + We have to lock around the test to avoid several + concurrent compilations; the current lock feels too big, + the crit section can probably be made smaller, but the + behaviour is safe and avoids retry heuristics. +*/ + +/* + Key to the control/smtproutes parser + [host]:[relay[:port]] + An ip in square brackets is acceptable in host and relay, even ipv6 + + + 0 1 2 3 4 5 6 7 8 9 +st\ev EOF # \n : [ ] 0-9 a-f other special + +0 h n n n +START END COMMENT START RELAY QHOST X HOST HOST HOST X + +1 +COMMENT END COMMENT START COMMENT COMMENT COMMENT COMMENT COMMENT COMMENT COMMENT + +2 n n n +QHOST X X X QHOST X EHOST QHOST QHOST X X + +3 n h n n n +HOST X HOST X RELAY X X HOST HOST HOST X + +4 h +EHOST X X X RELAY X X X X X X + +5 ra n ra r n n n +RELAY END INRELAY START PORT QRELAY X INRELAY INRELAY INRELAY X + +6 n n n +QRELAY X X X QRELAY X ERELAY QRELAY QRELAY X X + +7 ra ra r n n n +INRELAY END X START PORT X X INRELAY INRELAY INRELAY X + +8 ra ra r +ERELAY END X START PORT X X X X X X + +9 pa pa n +PORT END X START X X X PORT X X X + +END=a, X=b + +0x0100 n push character +0x0200 h compute host length +0x0400 r compute relay length +0x0800 p compute port +0x1000 a add route entry +*/ + +static inline uint8_t cclass (char c) +{ + static uint8_t const table[128] = "0999999999299999999999999999999998918889999898786666666666399898877777788888888888888888884958898888888888888888888888888899999" ; + return c & 0x80 ? 9 : table[(uint8_t)c] - '0' ; +} + +static inline char getnext (buffer *b) +{ + char c ; + ssize_t r = buffer_get(b, &c, 1) ; + if (r == -1) qmailr_tempsys("Unable to read from control/smtproutes") ; + return r ? c : 0 ; +} + +static inline void smtproutes_compile (int fdr, int fdw) +{ + static uint16_t const table[10][10] = + { + { 0x000a, 0x0001, 0x0000, 0x0205, 0x0002, 0x000b, 0x0103, 0x0103, 0x0103, 0x000b }, + { 0x000a, 0x0001, 0x0000, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001 }, + { 0x000b, 0x000b, 0x000b, 0x0102, 0x000b, 0x0004, 0x0102, 0x0102, 0x0102, 0x000b }, + { 0x000b, 0x0103, 0x000b, 0x0205, 0x000b, 0x000b, 0x0103, 0x0103, 0x0103, 0x000b }, + { 0x000b, 0x000b, 0x000b, 0x0205, 0x000b, 0x000b, 0x000b, 0x000b, 0x000b, 0x000b }, + { 0x140a, 0x0107, 0x1400, 0x0409, 0x0006, 0x000b, 0x0107, 0x0107, 0x0107, 0x000b }, + { 0x000b, 0x000b, 0x000b, 0x0106, 0x000b, 0x0008, 0x0106, 0x0106, 0x0106, 0x000b }, + { 0x140a, 0x000b, 0x1400, 0x0409, 0x000b, 0x000b, 0x0107, 0x0107, 0x0107, 0x000b }, + { 0x140a, 0x000b, 0x1400, 0x0409, 0x000b, 0x000b, 0x000b, 0x000b, 0x000b, 0x000b }, + { 0x180a, 0x000b, 0x1800, 0x000b, 0x000b, 0x000b, 0x0109, 0x000b, 0x000b, 0x000b } + } ; + cdbmaker cm = CDBMAKER_ZERO ; + stralloc sa = STRALLOC_ZERO ; + char buf[2048] ; + buffer b = BUFFER_INIT(&buffer_read, fdr, buf, 2048) ; + uint32_t relaypos = 0, relayend = 0 ; + uint8_t state = 0 ; + if (!cdbmake_start(&cm, fdw)) qmailr_tempsys("Unable to cdbmake_start") ; + + while (state < 0x0a) + { + char c = getnext(&b) ; + uint16_t val = table[state][cclass(c)] ; + state = val & 0x000f ; + if (val & 0x0100) + { + if (!stralloc_catb(&sa, &c, 1)) qmailr_tempsys("Unable to grow stralloc") ; + } + if (val & 0x0200) + { + relaypos = sa.len + 1 ; + if (!stralloc_catb(&sa, "\0\0\31", 3)) qmailr_tempsys("Unable to grow stralloc") ; + } + if (val & 0x0400) + { + if (!stralloc_0(&sa)) qmailr_tempsys("Unable to grow stralloc") ; + relayend = sa.len ; + } + if (val & 0x0800) + { + uint16_t port ; + if (!stralloc_0(&sa)) qmailr_tempsys("Unable to grow stralloc") ; + if (!uint160_scan(sa.s + relayend, &port)) qmailr_temp("Invalid port in control/smtproutes") ; + uint16_pack_big(sa.s + relaypos, port) ; + } + if (val & 0x0100) + { + if (relaypos > 1 || relayend > 2 + relaypos) + if (!cdbmake_add(&cm, sa.s, relaypos, sa.s + relaypos, relayend - relaypos)) + qmailr_tempsys("Unable to cdbmake_add") ; + sa.len = 0 ; + } + } + if (state != 0x0a) qmailr_temp("Syntax error in control/smtproutes") ; + stralloc_free(&sa) ; + if (!cdbmake_finish(&cm)) qmailr_tempsys("Unable to cdbmake_finish") ; +} + +int smtproutes_init (smtproutes *routes) +{ + static char const *cdbfile = SMTPD_STARTTLS_PROXY_QMAIL_HOME "/run/qmail-remote/smtproutes.cdb" ; + static char const *lckfile = SMTPD_STARTTLS_PROXY_QMAIL_HOME "/run/qmail-remote/smtproutes.lock" ; + static char const *txtfile = SMTPD_STARTTLS_PROXY_QMAIL_HOME "/control/smtproutes" ; + static size_t const cdblen = sizeof(cdbfile) - 1 ; + int fdl = openc_create(lckfile) ; + if (fdl == -1) qmailr_tempsys("Unable to open run/qmail-remote/smtproutes.lock") ; + if (fd_lock(fdl, 1, 0) == -1) qmailr_tempsys("Unable to lock run/qmail-remote/smtproutes.lock") ; + + int fdc = openc_read(cdbfile) ; + if (fdc >= 0) + { + struct stat stc, str ; + if (fstat(fdc, &stc) == -1) qmailr_tempsys("Unable to fstat run/qmail-remote/smtproutes.cdb") ; + if (stat(txtfile, &str) == -1) + { + if (errno != ENOENT) qmailr_tempsys("Unable to fstat control/smtproutes") ; + unlink_void(cdbfile) ; + fd_close(fdc) ; + goto zero ; + } + if (timespec_cmp(&stc.st_mtim, &str.st_mtim) > 0) goto useit ; + fd_close(fdc) ; + } + + int fdr = openc_read(txtfile) ; + if (fdr == -1) + { + if (errno != ENOENT) qmailr_tempsys("Unable to open control/smtproutes") ; + goto zero ; + } + + { + char tmp[cdblen + 8] ; + memcpy(tmp, cdbfile, cdblen) ; + memcpy(tmp + cdblen, ":XXXXXX", 8) ; + fdc = mkstemp(tmp) ; + if (fdc == -1) qmailr_tempsys("Unable to mkstemp") ; + smtproutes_compile(fdr, fdc) ; + if (lseek(fdc, 0, SEEK_SET) == -1) qmailr_tempsys("Unable to lseek") ; + if (fsync(fdc) == -1) qmailr_tempsys("Unable to fsync run/qmail-remote/smtproutes.cdb") ; + fd_close(fdr) ; + if (rename(tmp, cdbfile) == -1) unlink_void(tmp) ; + } + + useit: + if (!cdb_init_fromfd(&routes->map, fdc)) qmailr_tempsys("Unable to mmap run/qmail-remote/smtproutes.cdb") ; + fd_close(fdc) ; + fd_close(fdl) ; + return 1 ; + + zero: + fd_close(fdl) ; + errno = 0 ; + return 0 ; +} + +int smtproutes_match (smtproutes const *routes, char const *s, stralloc *sa, size_t *pos, uint16_t *port) +{ + cdb_data data ; + int r = cdb_find(&routes->map, &data, s, strlen(s)) ; + if (r == -1) qmailr_temp("Invalid run/qmail-remote/smtproutes.cdb") ; + if (!r) return 0 ; + if (data.len < 3) return 0 ; + if (data.s[data.len - 1]) qmailr_temp("Invalid run/qmail-remote/smtproutes.cdb") ; + *pos = sa->len ; + uint16_unpack_big(data.s, port) ; + if (!stralloc_catb(sa, data.s + 2, data.len - 2)) qmailr_tempsys("Unable to grow stralloc") ; + return 1 ; +} + +void smtproutes_free (smtproutes *routes) +{ + cdb_free(&routes->map) ; +} |