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Diffstat (limited to 'networking/inetd.c')
| -rw-r--r-- | networking/inetd.c | 1280 |
1 files changed, 1280 insertions, 0 deletions
diff --git a/networking/inetd.c b/networking/inetd.c new file mode 100644 index 0000000..047358c --- /dev/null +++ b/networking/inetd.c @@ -0,0 +1,1280 @@ +/* + * Copyright (c) 1983,1991 The Regents of the University of California. + * All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * David A. Holland. + * + * Busybox port by Vladimir Oleynik (C) 2001-2003 <dzo@simtreas.ru> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +/* + * Inetd - Internet super-server + * + * This program invokes all internet services as needed. + * connection-oriented services are invoked each time a + * connection is made, by creating a process. This process + * is passed the connection as file descriptor 0 and is + * expected to do a getpeername to find out the source host + * and port. + * + * Datagram oriented services are invoked when a datagram + * arrives; a process is created and passed a pending message + * on file descriptor 0. Datagram servers may either connect + * to their peer, freeing up the original socket for inetd + * to receive further messages on, or ``take over the socket'', + * processing all arriving datagrams and, eventually, timing + * out. The first type of server is said to be ``multi-threaded''; + * the second type of server ``single-threaded''. + * + * Inetd uses a configuration file which is read at startup + * and, possibly, at some later time in response to a hangup signal. + * The configuration file is ``free format'' with fields given in the + * order shown below. Continuation lines for an entry must being with + * a space or tab. All fields must be present in each entry. + * + * service name must be in /etc/services + * socket type stream/dgram/raw/rdm/seqpacket + * protocol must be in /etc/protocols + * wait/nowait[.max] single-threaded/multi-threaded, max # + * user[.group] user/group to run daemon as + * server program full path name + * server program arguments maximum of MAXARGS (20) + * + * RPC services unsuported + * + * Comment lines are indicated by a `#' in column 1. + */ + +/* + * Here's the scoop concerning the user.group feature: + * + * 1) No group listed. + * + * a) for root: NO setuid() or setgid() is done + * + * b) nonroot: setuid() + * setgid(primary group as found in passwd) + * initgroups(name, primary group) + * + * 2) set-group-option on. + * + * a) for root: NO setuid() + * setgid(specified group) + * setgroups(1, specified group) + * + * b) nonroot: setuid() + * setgid(specified group) + * initgroups(name, specified group) + * + * All supplementary groups are discarded at startup in case inetd was + * run manually. + */ + +#define __USE_BSD_SIGNAL + +#include "busybox.h" + +#include <sys/param.h> +#include <sys/stat.h> +#include <sys/ioctl.h> +#include <sys/socket.h> +#include <sys/un.h> +#include <sys/file.h> +#include <sys/wait.h> +#include <sys/time.h> +#include <sys/resource.h> + +#ifndef __linux__ +#ifndef RLIMIT_NOFILE +#define RLIMIT_NOFILE RLIMIT_OFILE +#endif +#endif + +#include <sys/param.h> +#include <sys/stat.h> +#include <sys/ioctl.h> +#include <sys/socket.h> +#include <sys/file.h> +#include <sys/wait.h> +#include <sys/time.h> +#include <sys/resource.h> + +#include <netinet/in.h> +#include <netinet/ip.h> +#include <arpa/inet.h> + +#include <errno.h> +#include <signal.h> +#include <netdb.h> +#include <syslog.h> +#include <pwd.h> +#include <grp.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <getopt.h> +#include <unistd.h> +#include <stdarg.h> + +#define _PATH_INETDCONF "/etc/inetd.conf" +#define _PATH_INETDPID "/var/run/inetd.pid" + +#ifndef MIN +#define MIN(a, b) ((a) < (b) ? (a) : (b)) +#endif + +#define TOOMANY 40 /* don't start more than TOOMANY */ +#define CNT_INTVL 60 /* servers in CNT_INTVL sec. */ +#define RETRYTIME (60*10) /* retry after bind or server fail */ + +#ifndef OPEN_MAX +#define OPEN_MAX 64 +#endif + + +/* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */ +#define FD_MARGIN (8) +static int rlim_ofile_cur = OPEN_MAX; + +#ifdef RLIMIT_NOFILE +static struct rlimit rlim_ofile; +#endif + + +static struct servtab { + char *se_service; /* name of service */ + int se_socktype; /* type of socket to use */ + int se_family; /* address family */ + char *se_proto; /* protocol used */ + short se_wait; /* single threaded server */ + short se_checked; /* looked at during merge */ + char *se_user; /* user name to run as */ + char *se_group; /* group name to run as */ +#ifndef INETD_UNSUPPORT_BILTIN + const struct biltin *se_bi; /* if built-in, description */ +#endif + char *se_server; /* server program */ +#define MAXARGV 20 + char *se_argv[MAXARGV+1]; /* program arguments */ + int se_fd; /* open descriptor */ + union { + struct sockaddr se_un_ctrladdr; + struct sockaddr_in se_un_ctrladdr_in; + struct sockaddr_un se_un_ctrladdr_un; + } se_un; /* bound address */ +#define se_ctrladdr se_un.se_un_ctrladdr +#define se_ctrladdr_in se_un.se_un_ctrladdr_in +#define se_ctrladdr_un se_un.se_un_ctrladdr_un + int se_ctrladdr_size; + int se_max; /* max # of instances of this service */ + int se_count; /* number started since se_time */ + struct timeval se_time; /* start of se_count */ + struct servtab *se_next; +} *servtab; + +/* Length of socket listen queue. Should be per-service probably. */ +static int global_queuelen = 128; + +static int nsock, maxsock; +static fd_set allsock; +static int timingout; +static sigset_t blockmask, emptymask; + + +#define INETD_UNSUPPORT_BILTIN 1 + + /* Echo received data */ +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_ECHO +#undef INETD_UNSUPPORT_BILTIN +static void echo_stream(int, struct servtab *); +static void echo_dg(int, struct servtab *); +#endif + /* Internet /dev/null */ +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DISCARD +#undef INETD_UNSUPPORT_BILTIN +static void discard_stream(int, struct servtab *); +static void discard_dg(int, struct servtab *); +#endif + /* Return 32 bit time since 1900 */ +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_TIME +#undef INETD_UNSUPPORT_BILTIN +static void machtime_stream(int, struct servtab *); +static void machtime_dg(int, struct servtab *); +#endif + /* Return human-readable time */ +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DAYTIME +#undef INETD_UNSUPPORT_BILTIN +static void daytime_stream(int, struct servtab *); +static void daytime_dg(int, struct servtab *); +#endif + /* Familiar character generator */ +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_CHARGEN +#undef INETD_UNSUPPORT_BILTIN +static void chargen_stream(int, struct servtab *); +static void chargen_dg(int, struct servtab *); +#endif + +#ifndef INETD_UNSUPPORT_BILTIN +struct biltin { + const char *bi_service; /* internally provided service name */ + int bi_socktype; /* type of socket supported */ + short bi_fork; /* 1 if should fork before call */ + short bi_wait; /* 1 if should wait for child */ + void (*bi_fn)(int, struct servtab *); /* fn which performs it */ +}; + +static const struct biltin biltins[] = { +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_ECHO + /* Echo received data */ + { "echo", SOCK_STREAM, 1, 0, echo_stream, }, + { "echo", SOCK_DGRAM, 0, 0, echo_dg, }, +#endif +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DISCARD + /* Internet /dev/null */ + { "discard", SOCK_STREAM, 1, 0, discard_stream, }, + { "discard", SOCK_DGRAM, 0, 0, discard_dg, }, +#endif +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_TIME + /* Return 32 bit time since 1900 */ + { "time", SOCK_STREAM, 0, 0, machtime_stream, }, + { "time", SOCK_DGRAM, 0, 0, machtime_dg, }, +#endif +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DAYTIME + /* Return human-readable time */ + { "daytime", SOCK_STREAM, 0, 0, daytime_stream, }, + { "daytime", SOCK_DGRAM, 0, 0, daytime_dg, }, +#endif +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_CHARGEN + /* Familiar character generator */ + { "chargen", SOCK_STREAM, 1, 0, chargen_stream, }, + { "chargen", SOCK_DGRAM, 0, 0, chargen_dg, }, +#endif + { NULL, 0, 0, 0, NULL } +}; +#endif /* INETD_UNSUPPORT_BILTIN */ + +#define NUMINT (sizeof(intab) / sizeof(struct inent)) +static const char *CONFIG = _PATH_INETDCONF; + +#define BCOPY(s, d, z) memcpy(d, s, z) + +static void +syslog_err_and_discard_dg(int se_socktype, const char *msg, ...) + __attribute__ ((noreturn, format (printf, 2, 3))); + +static void +syslog_err_and_discard_dg(int se_socktype, const char *msg, ...) +{ + char buf[50]; + va_list p; + + va_start(p, msg); + vsyslog(LOG_ERR, msg, p); + if (se_socktype != SOCK_STREAM) + recv(0, buf, sizeof (buf), 0); + _exit(1); +} + +static FILE *fconfig; +static char line[256]; + +static FILE * +setconfig(void) +{ + FILE *f = fconfig; + + if (f != NULL) { + fseek(f, 0L, L_SET); + } else { + f = fconfig = fopen(CONFIG, "r"); + if(f == NULL) + syslog(LOG_ERR, "%s: %m", CONFIG); + } + return f; +} + +static char * +nextline(void) +{ + char *cp; + FILE *fd = fconfig; + + if (fgets(line, sizeof (line), fd) == NULL) + return ((char *)0); + cp = strchr(line, '\n'); + if (cp) + *cp = '\0'; + return (line); +} + +static char * +skip(char **cpp) +{ + char *cp = *cpp; + char *start; + + if (*cpp == NULL) + return ((char *)0); + +again: + while (*cp == ' ' || *cp == '\t') + cp++; + if (*cp == '\0') { + int c; + + c = getc(fconfig); + (void) ungetc(c, fconfig); + if (c == ' ' || c == '\t') + if ((cp = nextline()) != NULL) + goto again; + *cpp = NULL; + return NULL; + } + start = cp; + while (*cp && *cp != ' ' && *cp != '\t') + cp++; + if (*cp != '\0') + *cp++ = '\0'; + *cpp = cp; + return (start); +} + +static char * +newstr(char *cp) +{ + cp = strdup(cp ? cp : ""); + if (cp) + return(cp); + + syslog_err_and_discard_dg(SOCK_STREAM, "strdup: %m"); +} + + +static struct servtab * +getconfigent(void) +{ + static struct servtab serv; + struct servtab *sep = &serv; + int argc; + char *cp, *arg; + +more: + while ((cp = nextline()) && *cp == '#') + ; + if (cp == NULL) + return ((struct servtab *)0); + memset((char *)sep, 0, sizeof *sep); + sep->se_service = newstr(skip(&cp)); + arg = skip(&cp); + if (arg == NULL) + goto more; + + if (strcmp(arg, "stream") == 0) + sep->se_socktype = SOCK_STREAM; + else if (strcmp(arg, "dgram") == 0) + sep->se_socktype = SOCK_DGRAM; + else if (strcmp(arg, "rdm") == 0) + sep->se_socktype = SOCK_RDM; + else if (strcmp(arg, "seqpacket") == 0) + sep->se_socktype = SOCK_SEQPACKET; + else if (strcmp(arg, "raw") == 0) + sep->se_socktype = SOCK_RAW; + else + sep->se_socktype = -1; + + sep->se_proto = newstr(skip(&cp)); + if (strcmp(sep->se_proto, "unix") == 0) { + sep->se_family = AF_UNIX; + } else { + sep->se_family = AF_INET; + if (strncmp(sep->se_proto, "rpc/", 4) == 0) { + syslog(LOG_ERR, "%s: rpc services not suported", + sep->se_service); + goto more; + } + } + arg = skip(&cp); + if (arg == NULL) + goto more; + { + char *s = strchr(arg, '.'); + if (s) { + *s++ = '\0'; + sep->se_max = atoi(s); + } else + sep->se_max = TOOMANY; + } + sep->se_wait = strcmp(arg, "wait") == 0; + sep->se_user = newstr(skip(&cp)); + sep->se_group = strchr(sep->se_user, '.'); + if (sep->se_group) { + *sep->se_group++ = '\0'; + } + sep->se_server = newstr(skip(&cp)); + if (strcmp(sep->se_server, "internal") == 0) { +#ifndef INETD_UNSUPPORT_BILTIN + const struct biltin *bi; + + for (bi = biltins; bi->bi_service; bi++) + if (bi->bi_socktype == sep->se_socktype && + strcmp(bi->bi_service, sep->se_service) == 0) + break; + if (bi->bi_service == 0) { + syslog(LOG_ERR, "internal service %s unknown", + sep->se_service); + goto more; + } + sep->se_bi = bi; + sep->se_wait = bi->bi_wait; +#else + syslog(LOG_ERR, "internal service %s unknown", + sep->se_service); + goto more; +#endif + } else +#ifndef INETD_UNSUPPORT_BILTIN + sep->se_bi = NULL +#endif + ; + argc = 0; + for (arg = skip(&cp); cp; arg = skip(&cp)) { + if (argc < MAXARGV) + sep->se_argv[argc++] = newstr(arg); + } + while (argc <= MAXARGV) + sep->se_argv[argc++] = NULL; + return (sep); +} + +static void +freeconfig(struct servtab *cp) +{ + int i; + + free(cp->se_service); + free(cp->se_proto); + free(cp->se_user); + /* Note: se_group is part of the newstr'ed se_user */ + free(cp->se_server); + for (i = 0; i < MAXARGV; i++) + free(cp->se_argv[i]); +} + +#ifndef INETD_UNSUPPORT_BILTIN +static char **Argv; +static char *LastArg; + +static void +setproctitle(char *a, int s) +{ + size_t size; + char *cp; + struct sockaddr_in sn; + char buf[80]; + + cp = Argv[0]; + size = sizeof(sn); + if (getpeername(s, (struct sockaddr *)&sn, &size) == 0) + (void) sprintf(buf, "-%s [%s]", a, inet_ntoa(sn.sin_addr)); + else + (void) sprintf(buf, "-%s", a); + strncpy(cp, buf, LastArg - cp); + cp += strlen(cp); + while (cp < LastArg) + *cp++ = ' '; +} +#endif /* INETD_UNSUPPORT_BILTIN */ + +static struct servtab * +enter(struct servtab *cp) +{ + struct servtab *sep; + sigset_t oldmask; + + sep = (struct servtab *)malloc(sizeof (*sep)); + if (sep == NULL) { + syslog_err_and_discard_dg(SOCK_STREAM, memory_exhausted); + } + *sep = *cp; + sep->se_fd = -1; + sigprocmask(SIG_BLOCK, &blockmask, &oldmask); + sep->se_next = servtab; + servtab = sep; + sigprocmask(SIG_SETMASK, &oldmask, NULL); + return (sep); +} + +static int +bump_nofile(void) +{ +#ifdef RLIMIT_NOFILE + +#define FD_CHUNK 32 + + struct rlimit rl; + + if (getrlimit(RLIMIT_NOFILE, &rl) < 0) { + syslog(LOG_ERR, "getrlimit: %m"); + return -1; + } + rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK); + if (rl.rlim_cur <= rlim_ofile_cur) { + syslog(LOG_ERR, + "bump_nofile: cannot extend file limit, max = %d", + rl.rlim_cur); + return -1; + } + + if (setrlimit(RLIMIT_NOFILE, &rl) < 0) { + syslog(LOG_ERR, "setrlimit: %m"); + return -1; + } + + rlim_ofile_cur = rl.rlim_cur; + return 0; + +#else + syslog(LOG_ERR, "bump_nofile: cannot extend file limit"); + return -1; +#endif +} + + +static void +setup(struct servtab *sep) +{ + int on = 1; + + if ((sep->se_fd = socket(sep->se_family, sep->se_socktype, 0)) < 0) { + syslog(LOG_ERR, "%s/%s: socket: %m", + sep->se_service, sep->se_proto); + return; + } + if (setsockopt(sep->se_fd, SOL_SOCKET, SO_REUSEADDR, (void *)&on, + sizeof(on)) < 0) + syslog(LOG_ERR, "setsockopt (SO_REUSEADDR): %m"); + if (bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size) < 0) { + syslog(LOG_ERR, "%s/%s: bind: %m", + sep->se_service, sep->se_proto); + (void) close(sep->se_fd); + sep->se_fd = -1; + if (!timingout) { + timingout = 1; + alarm(RETRYTIME); + } + return; + } + if (sep->se_socktype == SOCK_STREAM) + listen(sep->se_fd, global_queuelen); + + FD_SET(sep->se_fd, &allsock); + nsock++; + if (sep->se_fd > maxsock) { + maxsock = sep->se_fd; + if (maxsock > rlim_ofile_cur - FD_MARGIN) + bump_nofile(); + } +} + +static void +config(int signum) +{ + struct servtab *sep, *cp, **sepp; + sigset_t oldmask; + unsigned n; + + (void)signum; + if (setconfig() == NULL) + return; + + for (sep = servtab; sep; sep = sep->se_next) + sep->se_checked = 0; + while ((cp = getconfigent()) != NULL) { + for (sep = servtab; sep; sep = sep->se_next) + if (strcmp(sep->se_service, cp->se_service) == 0 && + strcmp(sep->se_proto, cp->se_proto) == 0) + break; + if (sep != 0) { + int i; + +#define SWAP(type, a, b) {type c=(type)a; (type)a=(type)b; (type)b=(type)c;} + + sigprocmask(SIG_BLOCK, &emptymask, &oldmask); + /* + * sep->se_wait may be holding the pid of a daemon + * that we're waiting for. If so, don't overwrite + * it unless the config file explicitly says don't + * wait. + */ + if ( +#ifndef INETD_UNSUPPORT_BILTIN + cp->se_bi == 0 && +#endif + (sep->se_wait == 1 || cp->se_wait == 0)) + sep->se_wait = cp->se_wait; + if (cp->se_max != sep->se_max) + SWAP(int, cp->se_max, sep->se_max); + if (cp->se_user) + SWAP(char *, sep->se_user, cp->se_user); + if (cp->se_group) + SWAP(char *, sep->se_group, cp->se_group); + if (cp->se_server) + SWAP(char *, sep->se_server, cp->se_server); + for (i = 0; i < MAXARGV; i++) + SWAP(char *, sep->se_argv[i], cp->se_argv[i]); +#undef SWAP + sigprocmask(SIG_SETMASK, &oldmask, NULL); + freeconfig(cp); + } else { + sep = enter(cp); + } + sep->se_checked = 1; + + switch (sep->se_family) { + case AF_UNIX: + if (sep->se_fd != -1) + break; + (void)unlink(sep->se_service); + n = strlen(sep->se_service); + if (n > sizeof(sep->se_ctrladdr_un.sun_path) - 1) + n = sizeof(sep->se_ctrladdr_un.sun_path) - 1; + strncpy(sep->se_ctrladdr_un.sun_path, sep->se_service, n); + sep->se_ctrladdr_un.sun_family = AF_UNIX; + sep->se_ctrladdr_size = n + + sizeof sep->se_ctrladdr_un.sun_family; + setup(sep); + break; + case AF_INET: + sep->se_ctrladdr_in.sin_family = AF_INET; + sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in; + { + u_short port = htons(atoi(sep->se_service)); + + if (!port) { + struct servent *sp; + sp = getservbyname(sep->se_service, + sep->se_proto); + if (sp == 0) { + syslog(LOG_ERR, + "%s/%s: unknown service", + sep->se_service, sep->se_proto); + continue; + } + port = sp->s_port; + } + if (port != sep->se_ctrladdr_in.sin_port) { + sep->se_ctrladdr_in.sin_port = port; + if (sep->se_fd != -1) { + FD_CLR(sep->se_fd, &allsock); + nsock--; + (void) close(sep->se_fd); + } + sep->se_fd = -1; + } + if (sep->se_fd == -1) + setup(sep); + } + } + } + if (fconfig) { + (void) fclose(fconfig); + fconfig = NULL; + } + /* + * Purge anything not looked at above. + */ + sigprocmask(SIG_SETMASK, &blockmask, &oldmask); + sepp = &servtab; + while ((sep = *sepp) != NULL) { + if (sep->se_checked) { + sepp = &sep->se_next; + continue; + } + *sepp = sep->se_next; + if (sep->se_fd != -1) { + FD_CLR(sep->se_fd, &allsock); + nsock--; + (void) close(sep->se_fd); + } + if (sep->se_family == AF_UNIX) + (void)unlink(sep->se_service); + freeconfig(sep); + free((char *)sep); + } + sigprocmask(SIG_SETMASK, &oldmask, NULL); +} + + + +static void +reapchild(int signum) +{ + int status; + int pid; + struct servtab *sep; + + (void)signum; + for (;;) { + pid = wait3(&status, WNOHANG, (struct rusage *)0); + if (pid <= 0) + break; + for (sep = servtab; sep; sep = sep->se_next) + if (sep->se_wait == pid) { + if (WIFEXITED(status) && WEXITSTATUS(status)) + syslog(LOG_WARNING, + "%s: exit status 0x%x", + sep->se_server, WEXITSTATUS(status)); + else if (WIFSIGNALED(status)) + syslog(LOG_WARNING, + "%s: exit signal 0x%x", + sep->se_server, WTERMSIG(status)); + sep->se_wait = 1; + FD_SET(sep->se_fd, &allsock); + nsock++; + } + } +} + +static void +retry(int signum) +{ + struct servtab *sep; + + (void)signum; + timingout = 0; + for (sep = servtab; sep; sep = sep->se_next) { + if (sep->se_fd == -1) { + switch (sep->se_family) { + case AF_UNIX: + case AF_INET: + setup(sep); + break; + } + } + } +} + +static void +goaway(int signum) +{ + struct servtab *sep; + + (void)signum; + for (sep = servtab; sep; sep = sep->se_next) + if (sep->se_fd != -1 && sep->se_family == AF_UNIX) + (void)unlink(sep->se_service); + (void)unlink(_PATH_INETDPID); + exit(0); +} + + + +extern int +inetd_main(int argc, char *argv[]) +{ + struct servtab *sep; + struct passwd *pwd; + struct group *grp = NULL; + struct sigaction sa; + int ch, pid; + gid_t gid; + +#ifdef INETD_UNSUPPORT_BILTIN +# define dofork 1 +#else + int dofork; + extern char **environ; +#endif + + gid = getgid(); + setgroups(1, &gid); + +#ifndef INETD_UNSUPPORT_BILTIN + Argv = argv; + if (environ == 0 || *environ == 0) + environ = argv; + while (*environ) + environ++; + LastArg = environ[-1] + strlen(environ[-1]); +#endif + + while ((ch = getopt(argc, argv, "q:")) != EOF) + switch(ch) { + case 'q': + global_queuelen = atoi(optarg); + if (global_queuelen < 8) global_queuelen=8; + break; + default: + show_usage(); // "[-q len] [conf]" + } + argc -= optind; + argv += optind; + + if (argc > 0) + CONFIG = argv[0]; + + daemon(0, 0); + openlog(applet_name, LOG_PID | LOG_NOWAIT, LOG_DAEMON); + { + FILE *fp; + + if ((fp = fopen(_PATH_INETDPID, "w")) != NULL) { + fprintf(fp, "%u\n", getpid()); + (void)fclose(fp); + } + } + +#ifdef RLIMIT_NOFILE + if (getrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0) { + syslog(LOG_ERR, "getrlimit: %m"); + } else { + rlim_ofile_cur = rlim_ofile.rlim_cur; + if (rlim_ofile_cur == RLIM_INFINITY) /* ! */ + rlim_ofile_cur = OPEN_MAX; + } +#endif + + config(0); + + sigemptyset(&emptymask); + sigemptyset(&blockmask); + sigaddset(&blockmask, SIGCHLD); + sigaddset(&blockmask, SIGHUP); + sigaddset(&blockmask, SIGALRM); + + memset(&sa, 0, sizeof(sa)); + sa.sa_mask = blockmask; + sa.sa_handler = retry; + sigaction(SIGALRM, &sa, NULL); + sa.sa_handler = config; + sigaction(SIGHUP, &sa, NULL); + sa.sa_handler = reapchild; + sigaction(SIGCHLD, &sa, NULL); + sa.sa_handler = goaway; + sigaction(SIGTERM, &sa, NULL); + sa.sa_handler = goaway; + sigaction(SIGINT, &sa, NULL); + sa.sa_handler = SIG_IGN; + sigaction(SIGPIPE, &sa, NULL); + + { + /* space for daemons to overwrite environment for ps */ +#define DUMMYSIZE 100 + char dummy[DUMMYSIZE]; + + (void)memset(dummy, 'x', DUMMYSIZE - 1); + dummy[DUMMYSIZE - 1] = '\0'; + + (void)setenv("inetd_dummy", dummy, 1); + } + + for (;;) { + int n, ctrl; + fd_set readable; + + if (nsock == 0) { + sigprocmask(SIG_BLOCK, &blockmask, NULL); + while (nsock == 0) + sigsuspend(&emptymask); + sigprocmask(SIG_SETMASK, &emptymask, NULL); + } + readable = allsock; + if ((n = select(maxsock + 1, &readable, (fd_set *)0, + (fd_set *)0, (struct timeval *)0)) <= 0) { + if (n < 0 && errno != EINTR) + syslog(LOG_WARNING, "select: %m"); + sleep(1); + continue; + } + for (sep = servtab; n && sep; sep = sep->se_next) + if (sep->se_fd != -1 && FD_ISSET(sep->se_fd, &readable)) { + n--; + if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) { + /* Fixed AGC */ + fcntl(sep->se_fd, F_SETFL, O_NDELAY); + /* --------- */ + ctrl = accept(sep->se_fd, NULL, NULL); + fcntl(sep->se_fd, F_SETFL, 0); + if (ctrl < 0) { + if (errno == EINTR || errno == EWOULDBLOCK) + continue; + syslog(LOG_WARNING, "accept (for %s): %m", + sep->se_service); + continue; + } + } else + ctrl = sep->se_fd; + sigprocmask(SIG_BLOCK, &blockmask, NULL); + pid = 0; +#ifndef INETD_UNSUPPORT_BILTIN + dofork = (sep->se_bi == 0 || sep->se_bi->bi_fork); +#endif + if (dofork) { + if (sep->se_count++ == 0) + (void)gettimeofday(&sep->se_time, + (struct timezone *)0); + else if (sep->se_count >= sep->se_max) { + struct timeval now; + + (void)gettimeofday(&now, (struct timezone *)0); + if (now.tv_sec - sep->se_time.tv_sec > + CNT_INTVL) { + sep->se_time = now; + sep->se_count = 1; + } else { + syslog(LOG_ERR, + "%s/%s server failing (looping), service terminated", + sep->se_service, sep->se_proto); + FD_CLR(sep->se_fd, &allsock); + (void) close(sep->se_fd); + sep->se_fd = -1; + sep->se_count = 0; + nsock--; + sigprocmask(SIG_SETMASK, &emptymask, + NULL); + if (!timingout) { + timingout = 1; + alarm(RETRYTIME); + } + continue; + } + } + pid = fork(); + } + if (pid < 0) { + syslog(LOG_ERR, "fork: %m"); + if (sep->se_socktype == SOCK_STREAM) + close(ctrl); + sigprocmask(SIG_SETMASK, &emptymask, NULL); + sleep(1); + continue; + } + if (pid && sep->se_wait) { + sep->se_wait = pid; + FD_CLR(sep->se_fd, &allsock); + nsock--; + } + sigprocmask(SIG_SETMASK, &emptymask, NULL); + if (pid == 0) { +#ifndef INETD_UNSUPPORT_BILTIN + if (sep->se_bi) + (*sep->se_bi->bi_fn)(ctrl, sep); + else +#endif + { + if ((pwd = getpwnam(sep->se_user)) == NULL) { + syslog_err_and_discard_dg( + sep->se_socktype, + "getpwnam: %s: No such user", + sep->se_user); + } + if (sep->se_group && + (grp = getgrnam(sep->se_group)) == NULL) { + syslog_err_and_discard_dg( + sep->se_socktype, + "getgrnam: %s: No such group", + sep->se_group); + } + /* + * Ok. There are four cases here: + * 1. nonroot user, no group specified + * 2. nonroot user, some group specified + * 3. root user, no group specified + * 4. root user, some group specified + * In cases 2 and 4 we setgid to the specified + * group. In cases 1 and 2 we run initgroups + * to run with the groups of the given user. + * In case 4 we do setgroups to run with the + * given group. In case 3 we do nothing. + */ + if (pwd->pw_uid) { + if (sep->se_group) + pwd->pw_gid = grp->gr_gid; + setgid((gid_t)pwd->pw_gid); + initgroups(pwd->pw_name, pwd->pw_gid); + setuid((uid_t)pwd->pw_uid); + } else if (sep->se_group) { + setgid((gid_t)grp->gr_gid); + setgroups(1, &grp->gr_gid); + } + dup2(ctrl, 0); + close(ctrl); + dup2(0, 1); + dup2(0, 2); +#ifdef RLIMIT_NOFILE + if (rlim_ofile.rlim_cur != rlim_ofile_cur) { + if (setrlimit(RLIMIT_NOFILE, + &rlim_ofile) < 0) + syslog(LOG_ERR,"setrlimit: %m"); + } +#endif + for (ctrl = rlim_ofile_cur-1; --ctrl > 2; ) + (void)close(ctrl); + + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = SIG_DFL; + sigaction(SIGPIPE, &sa, NULL); + + execv(sep->se_server, sep->se_argv); + syslog_err_and_discard_dg(sep->se_socktype, + "execv %s: %m", sep->se_server); + } + } + if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) + close(ctrl); + } + } +} + + +/* + * Internet services provided internally by inetd: + */ +#define BUFSIZE 4096 + +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_ECHO +/* Echo service -- echo data back */ +static void +echo_stream(int s, struct servtab *sep) +{ + char buffer[BUFSIZE]; + int i; + + setproctitle(sep->se_service, s); + while ((i = read(s, buffer, sizeof(buffer))) > 0 && + write(s, buffer, i) > 0) + ; + exit(0); +} + +/* Echo service -- echo data back */ +static void +echo_dg(int s, struct servtab *sep) +{ + char buffer[BUFSIZE]; + int i; + size_t size; + struct sockaddr sa; + + (void)sep; + + size = sizeof(sa); + if ((i = recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size)) < 0) + return; + (void) sendto(s, buffer, i, 0, &sa, sizeof(sa)); +} +#endif /* CONFIG_FEATURE_INETD_SUPPORT_BILTIN_ECHO */ + + +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DISCARD +/* Discard service -- ignore data */ +static void +discard_stream(int s, struct servtab *sep) +{ + char buffer[BUFSIZE]; + + setproctitle(sep->se_service, s); + while ((errno = 0, read(s, buffer, sizeof(buffer)) > 0) || + errno == EINTR) + ; + exit(0); +} + +/* Discard service -- ignore data */ +static void +discard_dg(int s, struct servtab *sep) +{ + char buffer[BUFSIZE]; + (void)sep; + read(s, buffer, sizeof(buffer)); +} +#endif /* CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DISCARD */ + + +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_CHARGEN +#include <ctype.h> +#define LINESIZ 72 +static char ring[128]; +static char *endring; + +static void +initring(void) +{ + int i; + + endring = ring; + + for (i = 0; i <= 128; ++i) + if (isprint(i)) + *endring++ = i; +} + +/* Character generator */ +static void +chargen_stream(int s, struct servtab *sep) +{ + char *rs; + int len; + char text[LINESIZ+2]; + + setproctitle(sep->se_service, s); + + if (!endring) { + initring(); + rs = ring; + } + + text[LINESIZ] = '\r'; + text[LINESIZ + 1] = '\n'; + for (rs = ring;;) { + if ((len = endring - rs) >= LINESIZ) + BCOPY(rs, text, LINESIZ); + else { + BCOPY(rs, text, len); + BCOPY(ring, text + len, LINESIZ - len); + } + if (++rs == endring) + rs = ring; + if (write(s, text, sizeof(text)) != sizeof(text)) + break; + } + exit(0); +} + +/* Character generator */ +static void +chargen_dg(int s, struct servtab *sep) +{ + struct sockaddr sa; + static char *rs; + size_t len, size; + char text[LINESIZ+2]; + + (void)sep; + + if (endring == 0) { + initring(); + rs = ring; + } + + size = sizeof(sa); + if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0) + return; + + if ((len = endring - rs) >= LINESIZ) + BCOPY(rs, text, LINESIZ); + else { + BCOPY(rs, text, len); + BCOPY(ring, text + len, LINESIZ - len); + } + if (++rs == endring) + rs = ring; + text[LINESIZ] = '\r'; + text[LINESIZ + 1] = '\n'; + (void) sendto(s, text, sizeof(text), 0, &sa, sizeof(sa)); +} +#endif /* CONFIG_FEATURE_INETD_SUPPORT_BILTIN_CHARGEN */ + + +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_TIME +/* + * Return a machine readable date and time, in the form of the + * number of seconds since midnight, Jan 1, 1900. Since gettimeofday + * returns the number of seconds since midnight, Jan 1, 1970, + * we must add 2208988800 seconds to this figure to make up for + * some seventy years Bell Labs was asleep. + */ + +static long +machtime(void) +{ + struct timeval tv; + + if (gettimeofday(&tv, (struct timezone *)0) < 0) { + fprintf(stderr, "Unable to get time of day\n"); + return (0L); + } + return (htonl((long)tv.tv_sec + 2208988800UL)); +} + +static void +machtime_stream(int s, struct servtab *sep) +{ + long result; + (void)sep; + + result = machtime(); + write(s, (char *) &result, sizeof(result)); +} + +static void +machtime_dg(int s, struct servtab *sep) +{ + long result; + struct sockaddr sa; + size_t size; + (void)sep; + + size = sizeof(sa); + if (recvfrom(s, (char *)&result, sizeof(result), 0, &sa, &size) < 0) + return; + result = machtime(); + (void) sendto(s, (char *) &result, sizeof(result), 0, &sa, sizeof(sa)); +} +#endif /* CONFIG_FEATURE_INETD_SUPPORT_BILTIN_TIME */ + + +#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DAYTIME +/* Return human-readable time of day */ +static int +human_readable_time_sprintf(char *buffer) +{ + time_t clocc = time(NULL); + + return sprintf(buffer, "%.24s\r\n", ctime(&clocc)); +} + +static void +daytime_stream(int s, struct servtab *sep) +{ + char buffer[256]; + size_t st = human_readable_time_sprintf(buffer); + + (void)sep; + + write(s, buffer, st); +} + +/* Return human-readable time of day */ +static void +daytime_dg(int s, struct servtab *sep) +{ + char buffer[256]; + struct sockaddr sa; + size_t size; + + (void)sep; + + size = sizeof(sa); + if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0) + return; + size = human_readable_time_sprintf(buffer); + sendto(s, buffer, size, 0, &sa, sizeof(sa)); +} +#endif /* CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DAYTIME */ |