diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/qmail-remote/tls.c | 61 |
1 files changed, 49 insertions, 12 deletions
diff --git a/src/qmail-remote/tls.c b/src/qmail-remote/tls.c index 8c4c068..77be6f8 100644 --- a/src/qmail-remote/tls.c +++ b/src/qmail-remote/tls.c @@ -1,10 +1,12 @@ /* ISC license. */ +#include <sys/wait.h> #include <unistd.h> #include <limits.h> #include <skalibs/types.h> #include <skalibs/env.h> +#include <skalibs/allreadwrite.h> #include <skalibs/stralloc.h> #include <skalibs/cspawn.h> #include <skalibs/djbunix.h> @@ -16,11 +18,32 @@ #include "qmailr.h" #include "qmail-remote.h" +/* + Ideally, we would just exec into "s6-tlsc qmail-remote-io". + Unfortunately, the interface with qmail-rspawn is super weird: +we don't have access to stderr directly, stdout counts as both a +protocol channel and an error channel so we need to prepend +messages with Z|D|K and null-terminate them, and qmail-rspawn +hates a child that doesn't exit 0 or 111. + s6-tlsc writes error messages to its stderr and exits nonzero +and non-111 in important TLS failure cases that we want to report. +So instead of execing, we spawn it and stick around to translate +the exit code and the error message back to qmail-rspawn. +*/ + void run_tls (int fdr, char const *fmtip, unsigned int timeoutconnect, unsigned int timeoutremote, qmailr_tls const *qtls, size_t helopos, size_t const *eaddrpos, unsigned int n, char const *storage) { + int wstat ; + pid_t pid ; int fdw = dup(fdr) ; unsigned int m = 0 ; stralloc modif = STRALLOC_ZERO ; + cspawn_fileaction fa[2] = + { + [0] = { .type = CSPAWN_FA_CLOSE }, + [1] = { .type = CSPAWN_FA_MOVE, .x = { .fd2 = { [0] = 2 } } } + } ; + int p[2] ; char fmtr[UINT_FMT] ; char fmtw[UINT_FMT] ; char fmtt[UINT_FMT] ; @@ -28,6 +51,10 @@ void run_tls (int fdr, char const *fmtip, unsigned int timeoutconnect, unsigned char const *argv[20 + n] ; if (fdw == -1) qmailr_tempusys("duplicate file descriptor") ; + if (pipe(p) == -1) qmailr_tempusys("pipe") ; + fa[1].x.fd = p[0] ; + fa[1].x.fd2[1] = p[1] ; + if (!env_addmodif(&modif, "TLS_UID", 0) || !env_addmodif(&modif, "TLS_GID", 0) || !env_addmodif(&modif, qtls->flagtadir ? "CADIR" : "CAFILE", storage + qtls->tapos)) dienomem() ; if (qtls->flagclientcert) @@ -36,22 +63,13 @@ void run_tls (int fdr, char const *fmtip, unsigned int timeoutconnect, unsigned || !env_addmodif(&modif, "KEYFILE", storage + qtls->keypos)) dienomem() ; } - { - int devnull = open_readb("/dev/null") ; - if (devnull >= 0) - { - if (devnull < 3) qmailr_temp("weird fd configuration") ; - fd_move(2, devnull) ; - } - } - fmtr[uint_fmt(fmtr, (unsigned int)fdr)] = 0 ; fmtw[uint_fmt(fmtw, (unsigned int)fdw)] = 0 ; fmtt[uint_fmt(fmtt, timeoutremote)] = 0 ; fmtk[uint_fmt(fmtk, timeoutconnect > UINT_MAX/1000 ? UINT_MAX : timeoutconnect * 1000)] = 0 ; argv[m++] = S6_NETWORKING_EXTBINPREFIX "s6-tlsc" ; - argv[m++] = "-Sjzv0" ; + argv[m++] = "-Sjzv0" ; /* S = use close_notify, v0 = as silent as possible */ argv[m++] = "-K" ; argv[m++] = fmtk ; argv[m++] = "-6" ; @@ -72,6 +90,25 @@ void run_tls (int fdr, char const *fmtip, unsigned int timeoutconnect, unsigned argv[m++] = storage + helopos ; for (unsigned int i = 0 ; i < n ; i++) argv[m++] = storage + eaddrpos[i] ; argv[m++] = 0 ; - mexec_m(argv, modif.s, modif.len) ; - qmailr_tempusys("exec ", argv[0]) ; + pid = mspawn_m(argv, modif.s, modif.len, 0, fa, 2) ; + if (!pid) qmailr_tempusys("spawn ", argv[0]) ; + + stralloc_free(&modif) ; + fd_close(p[1]) ; + if (wait_pid(pid, &wstat) == -1) qmailr_tempusys("waitpid") ; + if (WIFSIGNALED(wstat)) + qmailr_tempusys("either s6-tlsc or qmail-remote-io crashed") ; + + { + char buf[4096] ; + size_t r = fd_read(p[0], buf, 4096) ; + if (r == -1) qmailr_tempusys("read from pipe") ; + if (r) + { + if (r == 4096) r-- ; + buf[r++] = 0 ; + qmailr_temp(buf) ; + } + } + _exit(0) ; } |