diff options
Diffstat (limited to 'src/conn-tools/s6-tcpserverd.c')
| -rw-r--r-- | src/conn-tools/s6-tcpserverd.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/src/conn-tools/s6-tcpserverd.c b/src/conn-tools/s6-tcpserverd.c new file mode 100644 index 0000000..5a15dd9 --- /dev/null +++ b/src/conn-tools/s6-tcpserverd.c @@ -0,0 +1,435 @@ +/* ISC license. */ + +#include <string.h> +#include <stdint.h> +#include <sys/stat.h> +#include <sys/wait.h> +#include <errno.h> +#include <unistd.h> +#include <fcntl.h> +#include <signal.h> + +#include <skalibs/posixplz.h> +#include <skalibs/uint16.h> +#include <skalibs/uint32.h> +#include <skalibs/types.h> +#include <skalibs/ip46.h> +#include <skalibs/allreadwrite.h> +#include <skalibs/sgetopt.h> +#include <skalibs/strerr.h> +#include <skalibs/fmtscan.h> +#include <skalibs/env.h> +#include <skalibs/cspawn.h> +#include <skalibs/djbunix.h> +#include <skalibs/sig.h> +#include <skalibs/selfpipe.h> +#include <skalibs/iopause.h> +#include <skalibs/socket.h> +#include <skalibs/genset.h> +#include <skalibs/avltreen.h> + +#define ABSOLUTE_MAXCONN 16384 + +#define USAGE "s6-tcpserverd [ -v verbosity ] [ -1 ] [ -c maxconn ] [ -C localmaxconn ] prog..." + +static uint32_t maxconn = 40 ; +static uint32_t localmaxconn = 40 ; +static uint32_t verbosity = 1 ; +static int cont = 1 ; +static int is6 ; + +typedef struct pidi_s pidi, *pidi_ref ; +struct pidi_s +{ + pid_t pid ; + uint32_t i ; +} ; + +static genset *pidis ; +#define PIDI(i) genset_p(pidi, pidis, (i)) +#define numconn genset_n(pidis) +static avltreen *by_pid ; + +static genset *ipnums ; +#define IP(i) (genset_p(char, ipnums, (i)) + 4) +#define NUMP(i) ((uint32_t *)genset_p(char, ipnums, (i))) +static avltreen *by_ip ; + +static char fmtmaxconn[UINT32_FMT + 1] = "/" ; +static char fmtlocalmaxconn[UINT32_FMT + 1] = "/" ; + + +static inline void dieusage () +{ + strerr_dieusage(100, USAGE) ; +} + +static inline void X (void) +{ + strerr_dief1x(101, "internal inconsistency. Please submit a bug-report.") ; +} + +static void *bypid_dtok (uint32_t d, void *aux) +{ + return &genset_p(pidi, (genset *)aux, d)->pid ; +} + +static int bypid_cmp (void const *a, void const *b, void *aux) +{ + (void)aux ; + pid_t aa = *(pid_t const *)a ; + pid_t bb = *(pid_t const *)b ; + return aa < bb ? -1 : aa > bb ; +} + +static void *byip_dtok (uint32_t d, void *aux) +{ + return genset_p(char, (genset *)aux, d) + 4 ; +} + +static int byip_cmp (void const *a, void const *b, void *aux) +{ + (void)aux ; + return memcmp(a, b, is6 ? 16 : 4) ; +} + +static inline void log_start (char const *fmtip, char const *fmtport) +{ + strerr_warni4x("starting - bound to ip ", fmtip, " port ", fmtport) ; +} + +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 inline void log_deny (char const *ip, uint16_t port, uint32_t num) +{ + char fmtip[IP46_FMT] ; + char fmtport[UINT16_FMT] ; + char fmtnum[UINT32_FMT] ; + fmtip[is6 ? ip6_fmt(fmtip, ip) : ip4_fmt(fmtip, ip)] = 0 ; + fmtport[uint16_fmt(fmtport, port)] = 0 ; + fmtnum[uint32_fmt(fmtnum, num)] = 0 ; + strerr_warni7sys("deny ", fmtip, ":", fmtport, " count ", fmtnum, fmtlocalmaxconn) ; +} + +static inline void log_accept (pid_t pid, char const *ip, uint16_t port, uint32_t num) +{ + char fmtip[IP46_FMT] ; + char fmtport[UINT16_FMT] ; + char fmtnum[UINT32_FMT] ; + char fmtpid[PID_FMT] ; + fmtip[is6 ? ip6_fmt(fmtip, ip) : ip4_fmt(fmtip, ip)] = 0 ; + fmtport[uint16_fmt(fmtport, port)] = 0 ; + fmtnum[uint32_fmt(fmtnum, num)] = 0 ; + fmtpid[pid_fmt(fmtpid, pid)] = 0 ; + strerr_warni9x("allow ", fmtip, ":", fmtport, " pid ", fmtpid, " count ", fmtnum, fmtlocalmaxconn) ; +} + +static inline void log_close (pid_t pid, char const *ip, int w) +{ + char fmtpid[PID_FMT] ; + char fmtw[UINT_FMT] ; + fmtpid[pid_fmt(fmtpid, pid)] = 0 ; + fmtw[uint_fmt(fmtw, WIFSIGNALED(w) ? WTERMSIG(w) : WEXITSTATUS(w))] = 0 ; + strerr_warni4x("end pid ", fmtpid, WIFSIGNALED(w) ? " signal " : " exitcode ", fmtw) ; +} + +static int killthem_iter (void *data, void *aux) +{ + kill(((pidi *)data)->pid, *(int *)aux) ; + return 1 ; +} + +static void killthem (int sig) +{ + genset_iter(pidis, &killthem_iter, &sig) ; +} + +static inline void wait_children (void) +{ + for (;;) + { + uint32_t d ; + int wstat ; + pid_t pid = wait_nohang(&wstat) ; + if (pid < 0) + if (errno != ECHILD) strerr_diefu1sys(111, "wait_nohang") ; + else break ; + else if (!pid) break ; + if (avltreen_search(by_pid, &pid, &d)) + { + uint32_t i = PIDI(d)->i ; + char ip[SKALIBS_IP_SIZE] ; + memcpy(ip, IP(i), is6 ? 16 : 4) ; + avltreen_delete(by_pid, &pid) ; + genset_delete(pidis, d) ; + if (!--*NUMP(i)) + { + avltreen_delete(by_ip, ip) ; + genset_delete(ipnums, i) ; + } + if (verbosity >= 2) + { + log_close(pid, ip, wstat) ; + log_status() ; + } + } + } +} + +static inline 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 and SIGCONT", " to all connections") ; + killthem(SIGTERM) ; + killthem(SIGCONT) ; + break ; + } + case SIGQUIT : + { + if (verbosity >= 2) + strerr_warni6x("received ", "SIGQUIT,", " sending ", "SIGTERM and 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() ; + } +} + +static inline void new_connection (int s, char const *ip, uint16_t port, char const *const *argv, char const *const *envp, char *modifs, size_t m, size_t envlen) +{ + pid_t pid ; + uint32_t d ; + uint32_t num = avltreen_search(by_ip, ip, &d) ? *NUMP(d) : 0 ; + if (num >= localmaxconn) + { + log_deny(ip, port, num) ; + return ; + } + + m += is6 ? ip6_fmt(modifs + m, ip) : ip4_fmt(modifs + m, ip) ; + modifs[m++] = 0 ; + memcpy(modifs + m, "TCPREMOTEPORT=", 14) ; m += 14 ; + m += uint16_fmt(modifs + m, port) ; + modifs[m++] = 0 ; + memcpy(modifs + m, "TCPCONNNUM=", 11) ; m += 11 ; + m += uint32_fmt(modifs + m, num) ; + modifs[m++] = 0 ; + + { + cspawn_fileaction fa[2] = + { + [0] = { .type = CSPAWN_FA_MOVE, .x = { .fd2 = { [0] = 0, [1] = s } } }, + [1] = { .type = CSPAWN_FA_COPY, .x = { .fd2 = { [0] = 1, [1] = 0 } } } + } ; + char const *newenvp[envlen + 7] ; + env_mergen(newenvp, envlen + 7, envp, envlen, modifs, m, 6) ; + pid = cspawn(argv[0], argv, newenvp, CSPAWN_FLAGS_SELFPIPE_FINISH, fa, 2) ; + if (!pid) + { + if (verbosity) strerr_warnwu2sys("spawn ", argv[0]) ; + return ; + } + } + + if (num) (*NUMP(d))++ ; + else + { + d = genset_new(ipnums) ; + *NUMP(d) = 1 ; + memcpy(IP(d), ip, is6 ? 16 : 4) ; + avltreen_insert(by_ip, d) ; + } + + num = genset_new(pidis) ; + PIDI(num)->pid = pid ; + PIDI(num)->i = d ; + avltreen_insert(by_pid, num) ; + if (verbosity >= 2) + { + log_accept(pid, ip, port, *NUMP(d)) ; + log_status() ; + } +} + +int main (int argc, char const *const *argv) +{ + iopause_fd x[2] = { { .events = IOPAUSE_READ }, { .fd = 0, .events = IOPAUSE_READ | IOPAUSE_EXCEPT } } ; + int flag1 = 0 ; + PROG = "s6-tcpserverd" ; + { + subgetopt l = SUBGETOPT_ZERO ; + for (;;) + { + int opt = subgetopt_r(argc, argv, "1c:C:v:", &l) ; + if (opt == -1) break ; + switch (opt) + { + case '1' : flag1 = 1 ; break ; + case 'c' : if (!uint320_scan(l.arg, &maxconn)) dieusage() ; break ; + case 'C' : if (!uint320_scan(l.arg, &localmaxconn)) dieusage() ; break ; + case 'v' : if (!uint320_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) == -1 || ndelay_on(0) == -1) + strerr_diefu1sys(111, "set socket flags") ; + 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_altignore(SIGPIPE)) 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)) strerr_diefu1sys(111, "trap signals") ; + } + fmtlocalmaxconn[1+uint32_fmt(fmtlocalmaxconn+1, localmaxconn)] = 0 ; + } + + { + /* Yo dawg, I herd u like stack allocations */ + char ipnum_storage[maxconn * (is6 ? 20 : 8)] ; + uint32_t ipnum_freelist[maxconn] ; + avlnode byip_storage[maxconn] ; + uint32_t byip_freelist[maxconn] ; + pidi pidi_storage[maxconn] ; + uint32_t pidi_freelist[maxconn] ; + avlnode bypid_storage[maxconn] ; + uint32_t bypid_freelist[maxconn] ; + genset ipnum_info ; + genset pidi_info ; + avltreen byip_info ; + avltreen bypid_info ; + size_t envlen = env_len((char const *const *)environ) ; + size_t m = 21 ; + char ip[SKALIBS_IP_SIZE] ; + uint16_t port ; + char modifs[sizeof("PROTO=TCP TCPLOCALIP= TCPLOCALPORT= TCPREMOTEIP= TCPREMOTEPORT= TCPCONNNUM=") + 2 * (IP46_FMT + UINT16_FMT) + UINT32_FMT] = "PROTO=TCP\0TCPLOCALIP=" ; + + genset_init(&ipnum_info, ipnum_storage, ipnum_freelist, is6 ? 20 : 8, maxconn) ; + GENSET_init(&pidi_info, pidi, pidi_storage, pidi_freelist, maxconn) ; + avltreen_init(&byip_info, byip_storage, byip_freelist, maxconn, &byip_dtok, &byip_cmp, &ipnum_info) ; + avltreen_init(&bypid_info, bypid_storage, bypid_freelist, maxconn, &bypid_dtok, &bypid_cmp, &pidi_info) ; + ipnums = &ipnum_info ; + pidis = &pidi_info ; + by_ip = &byip_info ; + by_pid = &bypid_info ; + + { + size_t iplen, portlen ; + char fmtip[IP4_FMT] ; + char fmtport[UINT16_FMT] ; + ip46 loc ; + if (socket_local46(0, &loc, &port) == -1) + strerr_diefu1sys(111, "get local socket information") ; + is6 = ip46_is6(&loc) ; + memcpy(ip, loc.ip, is6 ? 16 : 4) ; + iplen = is6 ? ip6_fmt(fmtip, ip) : ip4_fmt(fmtip, ip) ; + portlen = uint16_fmt(fmtport, port) ; + memcpy(modifs + m, fmtip, iplen) ; m += iplen ; + memcpy(modifs + m, "\0TCPLOCALPORT=", 14) ; m += 14 ; + memcpy(modifs + m, fmtport, portlen) ; m += portlen ; + memcpy(modifs + m, "\0TCPREMOTEIP=", 13) ; m += 13 ; + + if (verbosity >= 2) + { + fmtmaxconn[1 + uint32_fmt(fmtmaxconn+1, maxconn)] = 0 ; + log_start(fmtip, fmtport) ; + log_status() ; + } + + if (flag1) + { + fmtport[portlen] = '\n' ; + allwrite(1, fmtport, portlen + 1) ; + close(1) ; + } + } + + while (cont) + { + if (iopause_g(x, 1 + (numconn < maxconn), 0) == -1) + strerr_diefu1sys(111, "iopause") ; + + if (x[0].revents & IOPAUSE_EXCEPT) strerr_dief1x(111, "trouble with selfpipe") ; + if (x[0].revents & IOPAUSE_READ) + { + handle_signals() ; + continue ; + } + if (numconn < maxconn) + { + if (x[1].revents & IOPAUSE_EXCEPT) strerr_dief1x(111, "trouble with socket") ; + if (x[1].revents & IOPAUSE_READ) + { + int fd = is6 ? socket_accept6(x[1].fd, ip, &port) : socket_accept4(x[1].fd, ip, &port) ; + if (fd == -1) + { + if (verbosity) strerr_warnwu1sys("accept") ; + } + else + { + new_connection(fd, ip, port, argv, (char const *const *)environ, modifs, m, envlen) ; + fd_close(fd) ; + } + } + } + } + } + if (verbosity >= 2) log_exit() ; + return 0 ; +} |