diff options
Diffstat (limited to 'src/minutils/s6-devd.c')
| -rw-r--r-- | src/minutils/s6-devd.c | 297 |
1 files changed, 56 insertions, 241 deletions
diff --git a/src/minutils/s6-devd.c b/src/minutils/s6-devd.c index f51550c..9df5c80 100644 --- a/src/minutils/s6-devd.c +++ b/src/minutils/s6-devd.c @@ -1,281 +1,96 @@ /* ISC license. */ -#ifndef _GNU_SOURCE -#define _GNU_SOURCE -#endif - -#include <sys/types.h> -#include <unistd.h> -#include <spawn.h> -#include <signal.h> -#include <sys/socket.h> -#include <linux/netlink.h> -#include <errno.h> -#include <skalibs/allreadwrite.h> -#include <skalibs/bytestr.h> #include <skalibs/uint.h> #include <skalibs/sgetopt.h> #include <skalibs/strerr2.h> -#include <skalibs/tai.h> -#include <skalibs/iopause.h> -#include <skalibs/env.h> #include <skalibs/djbunix.h> -#include <skalibs/sig.h> -#include <skalibs/selfpipe.h> +#include <s6-linux-utils/config.h> -#define USAGE "s6-devd [ -q | -v ] [ -b kbufsz ] [ -t maxlife:maxterm:maxkill ] helperprogram..." +#define USAGE "s6-devd [ -q | -v ] [ -b kbufsz ] [ -l linevar ] [ -t maxlife:maxterm:maxkill ] helperprogram..." #define dieusage() strerr_dieusage(100, USAGE) -static unsigned int cont = 1, state = 0, verbosity = 1 ; -static pid_t pid ; -static tain_t lifetto = TAIN_INFINITE_RELATIVE, - termtto = TAIN_INFINITE_RELATIVE, - killtto = TAIN_INFINITE_RELATIVE, - deadline ; - -static inline int fd_recvmsg (int fd, struct msghdr *hdr) -{ - int r ; - do r = recvmsg(fd, hdr, 0) ; - while ((r == -1) && (errno == EINTR)) ; - return r ; -} - -static inline int netlink_init (unsigned int kbufsz) -{ - struct sockaddr_nl nl = { .nl_family = AF_NETLINK, .nl_pad = 0, .nl_groups = 1, .nl_pid = 0 } ; - int fd = socket_internal(AF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT, DJBUNIX_FLAG_NB|DJBUNIX_FLAG_COE) ; - if (fd < 0) return -1 ; - if (bind(fd, (struct sockaddr *)&nl, sizeof(struct sockaddr_nl)) < 0) goto err ; - if (setsockopt(fd, SOL_SOCKET, SO_RCVBUFFORCE, &kbufsz, sizeof(unsigned int)) < 0) goto err ; - return fd ; - err: - { - register int e = errno ; - fd_close(fd) ; - errno = e ; - } - return -1 ; -} - -static inline void on_death (void) -{ - pid = 0 ; - state = 0 ; - tain_add_g(&deadline, &tain_infinite_relative) ; - if (cont == 2) cont = 0 ; -} - -static inline void on_event (char const *const *argv, char const *const *envp, char const *s, unsigned int len) -{ - unsigned int envlen = env_len(envp) ; - unsigned int n = envlen + 1 + byte_count(s, len, '\0') ; - int e ; - char const *v[n] ; - if (!env_merge(v, n, envp, envlen, s, len)) - strerr_diefu1sys(111, "env_merge") ; - e = posix_spawnp(&pid, argv[0], 0, 0, (char *const *)argv, (char * const *)v) ; - if (e) { errno = e ; strerr_diefu2sys(111, "spawn ", argv[0]) ; } - state = 1 ; - tain_add_g(&deadline, &lifetto) ; -} - -static inline void handle_timeout (void) +static inline int check_targ (char const *s) { - switch (state) - { - case 0 : - tain_add_g(&deadline, &tain_infinite_relative) ; - break ; - case 1 : - kill(pid, SIGTERM) ; - tain_add_g(&deadline, &termtto) ; - state++ ; - break ; - case 2 : - kill(pid, SIGKILL) ; - tain_add_g(&deadline, &killtto) ; - state++ ; - break ; - case 3 : - strerr_dief1x(99, "child resisted SIGKILL - check your kernel logs.") ; - default : - strerr_dief1x(101, "internal error: inconsistent state. Please submit a bug-report.") ; - } -} - -static inline void handle_signals (void) -{ - for (;;) - { - char c = selfpipe_read() ; - switch (c) - { - case -1 : strerr_diefu1sys(111, "selfpipe_read") ; - case 0 : return ; - case SIGTERM : - cont = pid ? 2 : 0 ; - break ; - case SIGCHLD : - if (!pid) wait_reap() ; - else - { - int wstat ; - int r = wait_pid_nohang(pid, &wstat) ; - if (r < 0) - if (errno != ECHILD) strerr_diefu1sys(111, "wait_pid_nohang") ; - else break ; - else if (!r) break ; - on_death() ; - } - break ; - default : - strerr_dief1x(101, "internal error: inconsistent signal state. Please submit a bug-report.") ; - } - } -} - -static inline void handle_netlink (int fd, char const *const *argv, char const *const *envp) -{ - char buf[4096] ; - int r ; - { - struct sockaddr_nl nl; - struct iovec iov = { .iov_base = &buf, .iov_len = sizeof(buf) } ; - char ctlmsg[CMSG_SPACE(sizeof(struct ucred))] ; - struct msghdr msg = { - .msg_name = &nl, - .msg_namelen = sizeof(struct sockaddr_nl), - .msg_iov = &iov, - .msg_iovlen = 1, - .msg_control = ctlmsg, - .msg_controllen = sizeof(ctlmsg), - .msg_flags = 0 - } ; - r = sanitize_read(fd_recvmsg(fd, &msg)) ; - if (r < 0) - { - if (errno == EPIPE) - { - if (verbosity >= 2) strerr_warnw1x("received EOF on netlink") ; - cont = 0 ; - return ; - } - else strerr_diefu1sys(111, "receive netlink message") ; - } - if (!r) return ; - if (r < 32 || r > 4096) - { - if (verbosity >= 2) - strerr_warnw2x("received and ignored netlink message ", "with invalid length") ; - return ; - } - if (nl.nl_pid) - { - if (verbosity >= 3) - { - char fmt[UINT_FMT] ; - fmt[uint_fmt(fmt, nl.nl_pid)] = 0 ; - strerr_warnw3x("received and ignored netlink message ", "from userspace process ", fmt) ; - } - return ; - } - } - { - unsigned int start = str_len(buf) + 1 ; - if (start < 5 || start > (unsigned int)r) - { - if (verbosity >= 2) - strerr_warnw3x("received and ignored netlink message ", "with invalid header", " length") ; - return ; - } - if (str_strn(buf, start, "@/", 2) >= start) - { - if (verbosity >= 2) - strerr_warnw2x("received and ignored netlink message ", "with invalid header") ; - return ; - } - on_event(argv, envp, buf + start, r - start) ; - } -} - -static inline int make_ttos (char const *s) -{ - unsigned int tlife = 0, tterm = 0, tkill = 0, pos = 0 ; - pos += uint_scan(s + pos, &tlife) ; + unsigned int t = 0, pos = 0 ; + pos += uint_scan(s + pos, &t) ; if (s[pos] && s[pos++] != ':') return 0 ; - if (!tlife) return 1 ; - tain_from_millisecs(&lifetto, tlife) ; - pos += uint_scan(s + pos, &tterm) ; + if (!t) return 1 ; + pos += uint_scan(s + pos, &t) ; if (s[pos] && s[pos++] != ':') return 0 ; - if (!tterm) return 1 ; - tain_from_millisecs(&termtto, tterm) ; - tain_add(&termtto, &termtto, &lifetto) ; - pos += uint_scan(s + pos, &tkill) ; + if (!t) return 1 ; + pos += uint_scan(s + pos, &t) ; if (s[pos]) return 0 ; - if (!tkill) return 1 ; - tain_from_millisecs(&killtto, tkill) ; - tain_add(&killtto, &killtto, &termtto) ; return 1 ; } int main (int argc, char const *const *argv, char const *const *envp) { - iopause_fd x[2] = { { -1, IOPAUSE_READ, 0 }, { -1, IOPAUSE_READ, 0 } } ; + unsigned int kbufsz = 65536, verbosity = 1 ; + char const *linevar = 0 ; + char const *targ = 0 ; PROG = "s6-devd" ; { - unsigned int kbufsz = 65536 ; subgetopt_t l = SUBGETOPT_ZERO ; for (;;) { - register int opt = subgetopt_r(argc, argv, "qvb:t:", &l) ; + register int opt = subgetopt_r(argc, argv, "qvb:l:t:", &l) ; if (opt == -1) break ; switch (opt) { case 'q' : if (verbosity) verbosity-- ; break ; case 'v' : verbosity++ ; break ; case 'b' : if (!uint0_scan(l.arg, &kbufsz)) dieusage() ; break ; - case 't' : if (!make_ttos(l.arg)) dieusage() ; break ; + case 'l' : linevar = l.arg ; break ; + case 't' : if (!check_targ(l.arg)) dieusage() ; targ = l.arg ; break ; default : dieusage() ; } } argc -= l.ind ; argv += l.ind ; - if (!argc) strerr_dieusage(100, USAGE) ; - close(0) ; - if (open_readb("/dev/null") < 0) strerr_diefu1sys(111, "open /dev/null for reading") ; - x[1].fd = netlink_init(kbufsz) ; - if (x[1].fd < 0) strerr_diefu1sys(111, "init netlink") ; - } - - x[0].fd = selfpipe_init() ; - if (x[0].fd == -1) strerr_diefu1sys(111, "init selfpipe") ; - if (sig_ignore(SIGPIPE) < 0) strerr_diefu1sys(111, "ignore SIGPIPE") ; - { - sigset_t set ; - sigemptyset(&set) ; - sigaddset(&set, SIGTERM) ; - sigaddset(&set, SIGCHLD) ; - if (selfpipe_trapset(&set) < 0) strerr_diefu1sys(111, "trap signals") ; } + if (!argc) strerr_dieusage(100, USAGE) ; - tain_now_g() ; - tain_add_g(&deadline, &tain_infinite_relative) ; - if (verbosity >= 2) strerr_warni1x("starting") ; - - while (cont) { - register int r = iopause_g(x, 1 + !pid, &deadline) ; - if (r < 0) strerr_diefu1sys(111, "iopause") ; - else if (!r) handle_timeout() ; - else + unsigned int m = 0, pos = 0 ; + char fmt[UINT_FMT * 3] ; + char const *newargv[argc + 15] ; + newargv[m++] = S6_LINUX_UTILS_BINPREFIX "s6-uevent-listener" ; + if (verbosity != 1) + { + newargv[m++] = "-v" ; + newargv[m++] = fmt + pos ; + pos += uint_fmt(fmt + pos, verbosity) ; + fmt[pos++] = 0 ; + } + if (kbufsz != 65536) + { + newargv[m++] = "-k" ; + newargv[m++] = fmt + pos ; + pos += uint_fmt(fmt + pos, kbufsz) ; + fmt[pos++] = 0 ; + } + newargv[m++] = "--" ; + newargv[m++] = S6_LINUX_UTILS_BINPREFIX "s6-uevent-spawner" ; + if (verbosity != 1) + { + newargv[m++] = "-v" ; + newargv[m++] = fmt + pos ; + pos += uint_fmt(fmt + pos, verbosity) ; + fmt[pos++] = 0 ; + } + if (linevar) + { + newargv[m++] = "-l" ; + newargv[m++] = linevar ; + } + if (targ) { - if ((x[0].revents | x[1].revents) & IOPAUSE_EXCEPT) - strerr_diefu1x(111, "iopause: trouble with pipes") ; - if (x[0].revents & IOPAUSE_READ) handle_signals() ; - else if (!pid && (x[1].revents & IOPAUSE_READ)) - handle_netlink(x[1].fd, argv, envp) ; + newargv[m++] = "-t" ; + newargv[m++] = targ ; } + newargv[m++] = "--" ; + while (*argv) newargv[m++] = *argv++ ; + newargv[m++] = 0 ; + pathexec_run(newargv[0], newargv, envp) ; + strerr_dieexec(111, newargv[0]) ; } - if (verbosity >= 2) strerr_warni1x("exiting") ; - return 0 ; } |