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authorLaurent Bercot <ska-skaware@skarnet.org>2015-01-07 01:12:01 +0000
committerLaurent Bercot <ska-skaware@skarnet.org>2015-01-07 01:12:01 +0000
commite3aeb3b63b9996bd06c20861e1dac1c9421d9312 (patch)
treef777537b8db0ae5241f5b6d4a20ca39351249bc1 /src/conn-tools/s6-tcpserver4d.c
parent80f1ebe9aaa1f5fb0ee796f005b0abda1628226d (diff)
downloads6-networking-e3aeb3b63b9996bd06c20861e1dac1c9421d9312.tar.xz
Experimental decoupling of socketbinders and daemons in ucspi servers.
Rewrite of s6-ipcserver as a small wrapper. s6-tcpserver4 and s6-tcpserver6 will follow.
Diffstat (limited to 'src/conn-tools/s6-tcpserver4d.c')
-rw-r--r--src/conn-tools/s6-tcpserver4d.c375
1 files changed, 375 insertions, 0 deletions
diff --git a/src/conn-tools/s6-tcpserver4d.c b/src/conn-tools/s6-tcpserver4d.c
new file mode 100644
index 0000000..c594b41
--- /dev/null
+++ b/src/conn-tools/s6-tcpserver4d.c
@@ -0,0 +1,375 @@
+/* ISC license. */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <skalibs/gccattributes.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/uint16.h>
+#include <skalibs/uint32.h>
+#include <skalibs/uint.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/sgetopt.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/fmtscan.h>
+#include <skalibs/diuint32.h>
+#include <skalibs/env.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/sig.h>
+#include <skalibs/selfpipe.h>
+#include <skalibs/iopause.h>
+#include <skalibs/socket.h>
+
+#define ABSOLUTE_MAXCONN 1000
+
+#define USAGE "s6-tcpserver4d [ -v verbosity ] [ -1 ] [ -c maxconn ] [ -C localmaxconn ] prog..."
+
+static unsigned int maxconn = 40 ;
+static unsigned int localmaxconn = 40 ;
+static unsigned int verbosity = 1 ;
+static int cont = 1 ;
+static diuint32 *pidip = 0 ;
+static unsigned int numconn = 0 ;
+static diuint32 *ipnum = 0 ;
+static unsigned int iplen = 0 ;
+
+static char fmtmaxconn[UINT_FMT+1] = "/" ;
+static char fmtlocalmaxconn[UINT_FMT+1] = "/" ;
+
+
+ /* 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_diuint32 (diuint32 const *, unsigned int, unsigned int) gccattr_pure ;
+static unsigned int lookup_diuint32 (diuint32 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 (uint32 pid)
+{
+ return lookup_diuint32(pidip, numconn, pid) ;
+}
+
+static inline unsigned int lookup_ip (uint32 ip)
+{
+ return lookup_diuint32(ipnum, iplen, ip) ;
+}
+
+
+ /* Logging */
+
+static 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 (uint32 ip, uint16 port, unsigned int num)
+{
+ char fmtip[UINT32_FMT] ;
+ char fmtport[UINT16_FMT] ;
+ char fmtnum[UINT_FMT] ;
+ fmtip[ip4_fmtu32(fmtip, ip)] = 0 ;
+ fmtport[uint16_fmt(fmtport, port)] = 0 ;
+ fmtnum[uint_fmt(fmtnum, num)] = 0 ;
+ strerr_warni7sys("deny ", fmtip, ":", fmtport, " count ", fmtnum, fmtlocalmaxconn) ;
+}
+
+static void log_accept (uint32 pid, uint32 ip, uint16 port, unsigned int num)
+{
+ char fmtipport[IP4_FMT + UINT16_FMT + 1] ;
+ char fmtpid[UINT32_FMT] ;
+ char fmtnum[UINT_FMT] ;
+ register unsigned int n ;
+ n = ip4_fmtu32(fmtipport, ip) ;
+ fmtipport[n++] = ':' ;
+ n += uint16_fmt(fmtipport + n, port) ;
+ fmtipport[n] = 0 ;
+ fmtnum[uint_fmt(fmtnum, num)] = 0 ;
+ fmtpid[uint32_fmt(fmtpid, pid)] = 0 ;
+ strerr_warni7x("allow ", fmtipport, " pid ", fmtpid, " count ", fmtnum, fmtlocalmaxconn) ;
+}
+
+static void log_close (uint32 pid, uint32 ip, int w)
+{
+ char fmtpid[UINT32_FMT] ;
+ char fmtip[IP4_FMT] = "?" ;
+ char fmtw[UINT_FMT] ;
+ fmtpid[uint32_fmt(fmtpid, pid)] = 0 ;
+ fmtip[ip4_fmtu32(fmtip, ip)] = 0 ;
+ fmtw[uint_fmt(fmtw, WIFSIGNALED(w) ? WTERMSIG(w) : WEXITSTATUS(w))] = 0 ;
+ strerr_warni6x("end pid ", fmtpid, " ip ", fmtip, WIFSIGNALED(w) ? " signal " : " exitcode ", fmtw) ;
+}
+
+
+ /* Signal handling */
+
+static void killthem (int sig)
+{
+ register unsigned int i = 0 ;
+ for (; i < numconn ; i++) kill(pidip[i].left, sig) ;
+}
+
+static void wait_children (void)
+{
+ for (;;)
+ {
+ unsigned int i ;
+ int w ;
+ register int 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) /* it's one of ours ! */
+ {
+ uint32 ip = pidip[i].right ;
+ register unsigned int j = lookup_ip(ip) ;
+ if (j >= iplen) X() ;
+ if (!--ipnum[j].right) ipnum[j] = ipnum[--iplen] ;
+ pidip[i] = pidip[--numconn] ;
+ if (verbosity >= 2)
+ {
+ log_close(pid, ip, 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, uint32, uint16, unsigned int, char const *const *, char const *const *) gccattr_noreturn ;
+static void run_child (int s, uint32 ip, uint16 port, unsigned int num, char const *const *argv, char const *const *envp)
+{
+ char fmt[74] ;
+ unsigned int n = 0 ;
+ PROG = "s6-tcpserver (child)" ;
+ if ((fd_move(0, s) < 0) || (fd_copy(1, 0) < 0))
+ strerr_diefu1sys(111, "move fds") ;
+ byte_copy(fmt+n, 22, "PROTO=TCP\0TCPREMOTEIP=") ; n += 22 ;
+ n += ip4_fmtu32(fmt+n, ip) ; fmt[n++] = 0 ;
+ byte_copy(fmt+n, 14, "TCPREMOTEPORT=") ; n += 14 ;
+ n += uint16_fmt(fmt+n, port) ; fmt[n++] = 0 ;
+ byte_copy(fmt+n, 11, "TCPCONNNUM=") ; n += 11 ;
+ n += uint_fmt(fmt+n, num) ; fmt[n++] = 0 ;
+ pathexec_r(argv, envp, env_len(envp), fmt, n) ;
+ strerr_dieexec(111, argv[0]) ;
+}
+
+static void new_connection (int s, uint32 ip, uint16 port, char const *const *argv, char const *const *envp)
+{
+ unsigned int i = lookup_ip(ip) ;
+ unsigned int num = (i < iplen) ? ipnum[i].right : 0 ;
+ register int pid ;
+ if (num >= localmaxconn)
+ {
+ log_deny(ip, port, num) ;
+ return ;
+ }
+ pid = fork() ;
+ if (pid < 0)
+ {
+ if (verbosity) strerr_warnwu1sys("fork") ;
+ return ;
+ }
+ else if (!pid)
+ {
+ selfpipe_finish() ;
+ run_child(s, ip, port, num+1, argv, envp) ;
+ }
+
+ if (i < iplen) ipnum[i].right = num + 1 ;
+ else
+ {
+ ipnum[iplen].left = ip ;
+ ipnum[iplen++].right = 1 ;
+ }
+ pidip[numconn].left = (uint32)pid ;
+ pidip[numconn++].right = ip ;
+ if (verbosity >= 2)
+ {
+ log_accept((uint32)pid, ip, port, ipnum[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-tcpserver4d" ;
+ {
+ subgetopt_t l = SUBGETOPT_ZERO ;
+ int flag1 = 0 ;
+ for (;;)
+ {
+ register int opt = subgetopt_r(argc, argv, "1c:C:v:", &l) ;
+ if (opt == -1) break ;
+ switch (opt)
+ {
+ 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 (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) ;
+ }
+ }
+
+ {
+ diuint32 inyostack[maxconn<<1] ;
+ pidip = inyostack ; ipnum = 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)
+ {
+ char packedip[4] ;
+ uint16 port ;
+ register int fd = socket_accept4(x[1].fd, packedip, &port) ;
+ if (fd < 0)
+ {
+ if (verbosity) strerr_warnwu1sys("accept") ;
+ }
+ else
+ {
+ uint32 ip ;
+ uint32_unpack_big(packedip, &ip) ;
+ new_connection(fd, ip, port, argv, envp) ;
+ fd_close(fd) ;
+ }
+ }
+ }
+ }
+ }
+ if (verbosity >= 2) log_exit() ;
+ return 0 ;
+}