From 87c5b2118efcee65eeda3f743d081ea9c2b866d9 Mon Sep 17 00:00:00 2001 From: Laurent Bercot Date: Thu, 15 Jan 2015 20:14:44 +0000 Subject: Move Unix domain utilities and access control utilites, as well as the accessrules library, from s6-networking to here --- src/conn-tools/s6-ipcserverd.c | 399 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 399 insertions(+) create mode 100644 src/conn-tools/s6-ipcserverd.c (limited to 'src/conn-tools/s6-ipcserverd.c') diff --git a/src/conn-tools/s6-ipcserverd.c b/src/conn-tools/s6-ipcserverd.c new file mode 100644 index 0000000..4afe5cc --- /dev/null +++ b/src/conn-tools/s6-ipcserverd.c @@ -0,0 +1,399 @@ +/* ISC license. */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define USAGE "s6-ipcserverd [ -v verbosity ] [ -1 ] [ -P | -p ] [ -c maxconn ] [ -C localmaxconn ] prog..." + +#define ABSOLUTE_MAXCONN 1000 + +static unsigned int maxconn = 40 ; +static unsigned int localmaxconn = 40 ; +static char fmtmaxconn[UINT_FMT+1] = "/" ; +static char fmtlocalmaxconn[UINT_FMT+1] = "/" ; +static int flaglookup = 1 ; +static unsigned int verbosity = 1 ; +static int cont = 1 ; + +static diuint *piduid ; +static unsigned int numconn = 0 ; +static diuint *uidnum ; +static unsigned int uidlen = 0 ; + + + /* Utility functions */ + +static inline void dieusage () +{ + strerr_dieusage(100, USAGE) ; +} + +static inline void X (void) +{ + strerr_dief1x(101, "internal inconsistency. Please submit a bug-report.") ; +} + + + /* Lookup primitives */ + +static unsigned int lookup_diuint (diuint const *tab, unsigned int tablen, unsigned int key) +{ + register unsigned int i = 0 ; + for (; i < tablen ; i++) if (key == tab[i].left) break ; + return i ; +} + +static inline unsigned int lookup_pid (unsigned int pid) +{ + return lookup_diuint(piduid, numconn, pid) ; +} + +static inline unsigned int lookup_uid (unsigned int uid) +{ + return lookup_diuint(uidnum, uidlen, uid) ; +} + + + /* Logging */ + +static inline void log_start (void) +{ + strerr_warni1x("starting") ; +} + +static inline void log_exit (void) +{ + strerr_warni1x("exiting") ; +} + +static void log_status (void) +{ + char fmt[UINT_FMT] ; + fmt[uint_fmt(fmt, numconn)] = 0 ; + strerr_warni3x("status: ", fmt, fmtmaxconn) ; +} + +static void log_deny (unsigned int uid, unsigned int gid, unsigned int num) +{ + char fmtuid[UINT_FMT] = "?" ; + char fmtgid[UINT_FMT] = "?" ; + char fmtnum[UINT_FMT] = "?" ; + if (flaglookup) + { + fmtuid[uint_fmt(fmtuid, uid)] = 0 ; + fmtgid[uint_fmt(fmtgid, gid)] = 0 ; + fmtnum[uint_fmt(fmtnum, num)] = 0 ; + } + strerr_warni7sys("deny ", fmtuid, ":", fmtgid, " count ", fmtnum, fmtlocalmaxconn) ; +} + +static void log_accept (unsigned int pid, unsigned int uid, unsigned int gid, unsigned int num) +{ + char fmtuidgid[UINT_FMT * 2 + 1] = "?:?" ; + char fmtpid[UINT_FMT] ; + char fmtnum[UINT_FMT] = "?" ; + if (flaglookup) + { + register unsigned int n = uint_fmt(fmtuidgid, uid) ; + fmtuidgid[n++] = ':' ; + n += uint_fmt(fmtuidgid + n, gid) ; + fmtuidgid[n] = 0 ; + fmtnum[uint_fmt(fmtnum, num)] = 0 ; + } + fmtpid[uint_fmt(fmtpid, pid)] = 0 ; + strerr_warni7x("allow ", fmtuidgid, " pid ", fmtpid, " count ", fmtnum, fmtlocalmaxconn) ; +} + +static void log_close (unsigned int pid, unsigned int uid, int w) +{ + char fmtpid[UINT_FMT] ; + char fmtuid[UINT_FMT] = "?" ; + char fmtw[UINT_FMT] ; + fmtpid[uint_fmt(fmtpid, pid)] = 0 ; + if (flaglookup) fmtuid[uint_fmt(fmtuid, uid)] = 0 ; + fmtw[uint_fmt(fmtw, WIFSIGNALED(w) ? WTERMSIG(w) : WEXITSTATUS(w))] = 0 ; + strerr_warni6x("end pid ", fmtpid, " uid ", fmtuid, WIFSIGNALED(w) ? " signal " : " exitcode ", fmtw) ; +} + + + /* Signal handling */ + +static void killthem (int sig) +{ + register unsigned int i = 0 ; + for (; i < numconn ; i++) kill(piduid[i].left, sig) ; +} + +static void wait_children (void) +{ + for (;;) + { + unsigned int i ; + int w ; + register pid_t pid = wait_nohang(&w) ; + if (pid < 0) + if (errno != ECHILD) strerr_diefu1sys(111, "wait_nohang") ; + else break ; + else if (!pid) break ; + i = lookup_pid(pid) ; + if (i < numconn) + { + unsigned int uid = piduid[i].right ; + register unsigned int j = lookup_uid(uid) ; + if (j >= uidlen) X() ; + if (!--uidnum[j].right) uidnum[j] = uidnum[--uidlen] ; + piduid[i] = piduid[--numconn] ; + if (verbosity >= 2) + { + log_close(pid, uid, w) ; + log_status() ; + } + } + } +} + +static void handle_signals (void) +{ + for (;;) switch (selfpipe_read()) + { + case -1 : strerr_diefu1sys(111, "read selfpipe") ; + case 0 : return ; + case SIGCHLD : wait_children() ; break ; + case SIGTERM : + { + if (verbosity >= 2) + strerr_warni3x("received ", "SIGTERM,", " quitting") ; + cont = 0 ; + break ; + } + case SIGHUP : + { + if (verbosity >= 2) + strerr_warni5x("received ", "SIGHUP,", " sending ", "SIGTERM+SIGCONT", " to all connections") ; + killthem(SIGTERM) ; + killthem(SIGCONT) ; + break ; + } + case SIGQUIT : + { + if (verbosity >= 2) + strerr_warni6x("received ", "SIGQUIT,", " sending ", "SIGTERM+SIGCONT", " to all connections", " and quitting") ; + cont = 0 ; + killthem(SIGTERM) ; + killthem(SIGCONT) ; + break ; + } + case SIGABRT : + { + if (verbosity >= 2) + strerr_warni6x("received ", "SIGABRT,", " sending ", "SIGKILL", " to all connections", " and quitting") ; + cont = 0 ; + killthem(SIGKILL) ; + break ; + } + default : X() ; + } +} + + + /* New connection handling */ + +static void run_child (int, unsigned int, unsigned int, unsigned int, char const *, char const *const *, char const *const *) gccattr_noreturn ; +static void run_child (int s, unsigned int uid, unsigned int gid, unsigned int num, char const *remotepath, char const *const *argv, char const *const *envp) +{ + unsigned int rplen = str_len(remotepath) + 1 ; + unsigned int n = 0 ; + char fmt[65 + UINT_FMT * 3 + rplen] ; + PROG = "s6-ipcserver (child)" ; + if ((fd_move(0, s) < 0) || (fd_copy(1, 0) < 0)) + strerr_diefu1sys(111, "move fds") ; + byte_copy(fmt+n, 23, "PROTO=IPC\0IPCREMOTEEUID") ; n += 23 ; + if (flaglookup) + { + fmt[n++] = '=' ; + n += uint_fmt(fmt+n, uid) ; + } + fmt[n++] = 0 ; + byte_copy(fmt+n, 13, "IPCREMOTEEGID") ; n += 13 ; + if (flaglookup) + { + fmt[n++] = '=' ; + n += uint_fmt(fmt+n, gid) ; + } + fmt[n++] = 0 ; + byte_copy(fmt+n, 11, "IPCCONNNUM=") ; n += 11 ; + if (flaglookup) n += uint_fmt(fmt+n, num) ; + fmt[n++] = 0 ; + byte_copy(fmt+n, 14, "IPCREMOTEPATH=") ; n += 14 ; + byte_copy(fmt+n, rplen, remotepath) ; n += rplen ; + pathexec_r(argv, envp, env_len(envp), fmt, n) ; + strerr_dieexec(111, argv[0]) ; +} + +static void new_connection (int s, char const *remotepath, char const *const *argv, char const *const *envp) +{ + unsigned int uid = 0, gid = 0 ; + unsigned int num, i ; + register pid_t pid ; + if (flaglookup && (ipc_eid(s, &uid, &gid) < 0)) + { + if (verbosity) strerr_warnwu1sys("ipc_eid") ; + return ; + } + i = lookup_uid(uid) ; + num = (i < uidlen) ? uidnum[i].right : 0 ; + if (num >= localmaxconn) + { + log_deny(uid, gid, num) ; + return ; + } + pid = fork() ; + if (pid < 0) + { + if (verbosity) strerr_warnwu1sys("fork") ; + return ; + } + else if (!pid) + { + selfpipe_finish() ; + run_child(s, uid, gid, num+1, remotepath, argv, envp) ; + } + + if (i < uidlen) uidnum[i].right = num + 1 ; + else + { + uidnum[uidlen].left = uid ; + uidnum[uidlen++].right = 1 ; + } + piduid[numconn].left = (unsigned int)pid ; + piduid[numconn++].right = uid ; + if (verbosity >= 2) + { + log_accept((unsigned int)pid, uid, gid, uidnum[i].right) ; + log_status() ; + } +} + + + /* And the main */ + +int main (int argc, char const *const *argv, char const *const *envp) +{ + iopause_fd x[2] = { { .events = IOPAUSE_READ }, { .fd = 0, .events = IOPAUSE_READ | IOPAUSE_EXCEPT } } ; + PROG = "s6-ipcserverd" ; + { + subgetopt_t l = SUBGETOPT_ZERO ; + int flag1 = 0 ; + for (;;) + { + register int opt = subgetopt_r(argc, argv, "Pp1c:C:v:", &l) ; + if (opt == -1) break ; + switch (opt) + { + case 'P' : flaglookup = 0 ; break ; + case 'p' : flaglookup = 1 ; break ; + case '1' : flag1 = 1 ; break ; + case 'c' : if (!uint0_scan(l.arg, &maxconn)) dieusage() ; break ; + case 'C' : if (!uint0_scan(l.arg, &localmaxconn)) dieusage() ; break ; + case 'v' : if (!uint0_scan(l.arg, &verbosity)) dieusage() ; break ; + default : dieusage() ; + } + } + argc -= l.ind ; argv += l.ind ; + if (!argc || !*argv[0]) dieusage() ; + { + struct stat st ; + if (fstat(0, &st) < 0) strerr_diefu1sys(111, "fstat stdin") ; + if (!S_ISSOCK(st.st_mode)) strerr_dief1x(100, "stdin is not a socket") ; + } + if (coe(0) < 0) strerr_diefu1sys(111, "make socket close-on-exec") ; + if (flag1) + { + if (fcntl(1, F_GETFD) < 0) + strerr_dief1sys(100, "called with option -1 but stdout said") ; + } + else close(1) ; + if (!maxconn) maxconn = 1 ; + if (maxconn > ABSOLUTE_MAXCONN) maxconn = ABSOLUTE_MAXCONN ; + if (!flaglookup || (localmaxconn > maxconn)) localmaxconn = maxconn ; + + x[0].fd = selfpipe_init() ; + if (x[0].fd == -1) strerr_diefu1sys(111, "create selfpipe") ; + if (sig_ignore(SIGPIPE) < 0) strerr_diefu1sys(111, "ignore SIGPIPE") ; + { + sigset_t set ; + sigemptyset(&set) ; + sigaddset(&set, SIGCHLD) ; + sigaddset(&set, SIGTERM) ; + sigaddset(&set, SIGHUP) ; + sigaddset(&set, SIGQUIT) ; + sigaddset(&set, SIGABRT) ; + if (selfpipe_trapset(&set) < 0) strerr_diefu1sys(111, "trap signals") ; + } + + fmtlocalmaxconn[1+uint_fmt(fmtlocalmaxconn+1, localmaxconn)] = 0 ; + if (verbosity >= 2) + { + fmtmaxconn[1+uint_fmt(fmtmaxconn+1, maxconn)] = 0 ; + log_start() ; + log_status() ; + } + if (flag1) + { + fd_write(1, "\n", 1) ; + fd_close(1) ; + } + } + + { + diuint inyostack[maxconn + (flaglookup ? maxconn : 1)] ; + piduid = inyostack ; uidnum = inyostack + maxconn ; + + while (cont) + { + if (iopause_g(x, 1 + (numconn < maxconn), 0) < 0) + strerr_diefu1sys(111, "iopause") ; + + if (x[0].revents & IOPAUSE_EXCEPT) strerr_dief1x(111, "trouble with selfpipe") ; + if (x[0].revents & IOPAUSE_READ) handle_signals() ; + if (numconn < maxconn) + { + if (x[1].revents & IOPAUSE_EXCEPT) strerr_dief1x(111, "trouble with socket") ; + if (x[1].revents & IOPAUSE_READ) + { + int dummy ; + char remotepath[IPCPATH_MAX+1] ; + register int s = ipc_accept(x[1].fd, remotepath, IPCPATH_MAX+1, &dummy) ; + if (s < 0) + { + if (verbosity) strerr_warnwu1sys("accept") ; + } + else + { + new_connection(s, remotepath, argv, envp) ; + fd_close(s) ; + } + } + } + } + } + if (verbosity >= 2) log_exit() ; + return 0 ; +} -- cgit v1.2.3