/* * tcpdchk - examine all tcpd access control rules and inetd.conf entries * * Usage: tcpdchk [-a] [-d] [-i inet_conf] [-v] * * -a: complain about implicit "allow" at end of rule. * * -d: rules in current directory. * * -i: location of inetd.conf file. * * -v: show all rules. * * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. */ #ifndef lint static char sccsid[] = "@(#) tcpdchk.c 1.8 97/02/12 02:13:25"; #endif /* System libraries. */ #include <sys/types.h> #include <sys/stat.h> #include <netinet/in.h> #include <arpa/inet.h> #include <stdio.h> #include <syslog.h> #include <setjmp.h> #include <errno.h> #include <netdb.h> #include <string.h> extern int errno; extern void exit(); extern int optind; extern char *optarg; #ifndef INADDR_NONE #define INADDR_NONE (-1) /* XXX should be 0xffffffff */ #endif #ifndef S_ISDIR #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR) #endif /* Application-specific. */ #include "tcpd.h" #include "inetcf.h" #include "scaffold.h" /* * Stolen from hosts_access.c... */ static char sep[] = ", \t\n"; #define BUFLEN 2048 int resident = 0; int hosts_access_verbose = 0; char *hosts_allow_table = HOSTS_ALLOW; char *hosts_deny_table = HOSTS_DENY; extern jmp_buf tcpd_buf; /* * Local stuff. */ static void usage(); static void parse_table(); static void print_list(); static void check_daemon_list(); static void check_client_list(); static void check_daemon(); static void check_user(); static int check_host(); static int reserved_name(); #define PERMIT 1 #define DENY 0 #define YES 1 #define NO 0 static int defl_verdict; static char *myname; static int allow_check; static char *inetcf; int main(argc, argv) int argc; char **argv; { struct request_info request; struct stat st; int c; myname = argv[0]; /* * Parse the JCL. */ while ((c = getopt(argc, argv, "adi:v")) != EOF) { switch (c) { case 'a': allow_check = 1; break; case 'd': hosts_allow_table = "hosts.allow"; hosts_deny_table = "hosts.deny"; break; case 'i': inetcf = optarg; break; case 'v': hosts_access_verbose++; break; default: usage(); /* NOTREACHED */ } } if (argc != optind) usage(); /* * When confusion really strikes... */ if (check_path(REAL_DAEMON_DIR, &st) < 0) { tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR); } else if (!S_ISDIR(st.st_mode)) { tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR); } /* * Process the inet configuration file (or its moral equivalent). This * information is used later to find references in hosts.allow/deny to * unwrapped services, and other possible problems. */ inetcf = inet_cfg(inetcf); if (hosts_access_verbose) printf("Using network configuration file: %s\n", inetcf); /* * These are not run from inetd but may have built-in access control. */ inet_set("portmap", WR_NOT); inet_set("rpcbind", WR_NOT); /* * Check accessibility of access control files. */ (void) check_path(hosts_allow_table, &st); (void) check_path(hosts_deny_table, &st); /* * Fake up an arbitrary service request. */ request_init(&request, RQ_DAEMON, "daemon_name", RQ_SERVER_NAME, "server_hostname", RQ_SERVER_ADDR, "server_addr", RQ_USER, "user_name", RQ_CLIENT_NAME, "client_hostname", RQ_CLIENT_ADDR, "client_addr", RQ_FILE, 1, 0); /* * Examine all access-control rules. */ defl_verdict = PERMIT; parse_table(hosts_allow_table, &request); defl_verdict = DENY; parse_table(hosts_deny_table, &request); return (0); } /* usage - explain */ static void usage() { fprintf(stderr, "usage: %s [-a] [-d] [-i inet_conf] [-v]\n", myname); fprintf(stderr, " -a: report rules with implicit \"ALLOW\" at end\n"); fprintf(stderr, " -d: use allow/deny files in current directory\n"); fprintf(stderr, " -i: location of inetd.conf file\n"); fprintf(stderr, " -v: list all rules\n"); exit(1); } /* parse_table - like table_match(), but examines _all_ entries */ static void parse_table(table, request) char *table; struct request_info *request; { FILE *fp; int real_verdict; char sv_list[BUFLEN]; /* becomes list of daemons */ char *cl_list; /* becomes list of requests */ char *sh_cmd; /* becomes optional shell command */ char buf[BUFSIZ]; int verdict; struct tcpd_context saved_context; saved_context = tcpd_context; /* stupid compilers */ if (fp = fopen(table, "r")) { tcpd_context.file = table; tcpd_context.line = 0; while (xgets(sv_list, sizeof(sv_list), fp)) { if (sv_list[strlen(sv_list) - 1] != '\n') { tcpd_warn("missing newline or line too long"); continue; } if (sv_list[0] == '#' || sv_list[strspn(sv_list, " \t\r\n")] == 0) continue; if ((cl_list = split_at(skip_ipv6_addrs(sv_list), ':')) == 0) { tcpd_warn("missing \":\" separator"); continue; } sh_cmd = split_at(skip_ipv6_addrs(cl_list), ':'); if (hosts_access_verbose) printf("\n>>> Rule %s line %d:\n", tcpd_context.file, tcpd_context.line); if (hosts_access_verbose) print_list("daemons: ", sv_list); check_daemon_list(sv_list); if (hosts_access_verbose) print_list("clients: ", cl_list); check_client_list(cl_list); #ifdef PROCESS_OPTIONS real_verdict = defl_verdict; if (sh_cmd) { verdict = setjmp(tcpd_buf); if (verdict != 0) { real_verdict = (verdict == AC_PERMIT); } else { dry_run = 1; process_options(sh_cmd, request); if (dry_run == 1 && real_verdict && allow_check) tcpd_warn("implicit \"allow\" at end of rule"); } } else if (defl_verdict && allow_check) { tcpd_warn("implicit \"allow\" at end of rule"); } if (hosts_access_verbose) printf("access: %s\n", real_verdict ? "granted" : "denied"); #else if (sh_cmd) shell_cmd(percent_x(buf, sizeof(buf), sh_cmd, request)); if (hosts_access_verbose) printf("access: %s\n", defl_verdict ? "granted" : "denied"); #endif } (void) fclose(fp); } else if (errno != ENOENT) { tcpd_warn("cannot open %s: %m", table); } tcpd_context = saved_context; } /* print_list - pretty-print a list */ static void print_list(title, list) char *title; char *list; { char buf[BUFLEN]; char *cp; char *next; fputs(title, stdout); strcpy(buf, list); for (cp = strtok(buf, sep); cp != 0; cp = next) { fputs(cp, stdout); next = strtok((char *) 0, sep); if (next != 0) fputs(" ", stdout); } fputs("\n", stdout); } /* check_daemon_list - criticize daemon list */ static void check_daemon_list(list) char *list; { char buf[BUFLEN]; char *cp; char *host; int daemons = 0; strcpy(buf, list); for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) { if (STR_EQ(cp, "EXCEPT")) { daemons = 0; } else { daemons++; if ((host = split_at(cp + 1, '@')) != 0 && check_host(host) > 1) { tcpd_warn("host %s has more than one address", host); tcpd_warn("(consider using an address instead)"); } check_daemon(cp); } } if (daemons == 0) tcpd_warn("daemon list is empty or ends in EXCEPT"); } /* check_client_list - criticize client list */ static void check_client_list(list) char *list; { char buf[BUFLEN]; char *cp; char *host; int clients = 0; strcpy(buf, list); for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) { if (STR_EQ(cp, "EXCEPT")) { clients = 0; } else { clients++; if (host = split_at(cp + 1, '@')) { /* user@host */ check_user(cp); check_host(host); } else { check_host(cp); } } } if (clients == 0) tcpd_warn("client list is empty or ends in EXCEPT"); } /* check_daemon - criticize daemon pattern */ static void check_daemon(pat) char *pat; { if (pat[0] == '@') { tcpd_warn("%s: daemon name begins with \"@\"", pat); } else if (pat[0] == '.') { tcpd_warn("%s: daemon name begins with dot", pat); } else if (pat[strlen(pat) - 1] == '.') { tcpd_warn("%s: daemon name ends in dot", pat); } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)) { /* void */ ; } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ tcpd_warn("FAIL is no longer recognized"); tcpd_warn("(use EXCEPT or DENY instead)"); } else if (reserved_name(pat)) { tcpd_warn("%s: daemon name may be reserved word", pat); } else { switch (inet_get(pat)) { case WR_UNKNOWN: tcpd_warn("%s: no such process name in %s", pat, inetcf); inet_set(pat, WR_YES); /* shut up next time */ break; case WR_NOT: tcpd_warn("%s: service possibly not wrapped", pat); inet_set(pat, WR_YES); break; } } } /* check_user - criticize user pattern */ static void check_user(pat) char *pat; { if (pat[0] == '@') { /* @netgroup */ tcpd_warn("%s: user name begins with \"@\"", pat); } else if (pat[0] == '.') { tcpd_warn("%s: user name begins with dot", pat); } else if (pat[strlen(pat) - 1] == '.') { tcpd_warn("%s: user name ends in dot", pat); } else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown) || STR_EQ(pat, "KNOWN")) { /* void */ ; } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ tcpd_warn("FAIL is no longer recognized"); tcpd_warn("(use EXCEPT or DENY instead)"); } else if (reserved_name(pat)) { tcpd_warn("%s: user name may be reserved word", pat); } } /* check_host - criticize host pattern */ static int check_host(pat) char *pat; { char *mask; int addr_count = 1; if (pat[0] == '@') { /* @netgroup */ #ifdef NO_NETGRENT /* SCO has no *netgrent() support */ #else #ifdef NETGROUP char *machinep; char *userp; char *domainp; setnetgrent(pat + 1); if (getnetgrent(&machinep, &userp, &domainp) == 0) tcpd_warn("%s: unknown or empty netgroup", pat + 1); endnetgrent(); #else tcpd_warn("netgroup support disabled"); #endif #endif #ifdef HAVE_IPV6 } else if (pat[0] == '[') { struct in6_addr in6; char *cbr = strchr(pat, ']'); char *slash = strchr(pat, '/'); int err = 0; int mask = IPV6_ABITS; if (slash != NULL) { *slash = '\0'; mask = atoi(slash + 1); err = mask < 0 || mask > IPV6_ABITS; } if (cbr == NULL) err = 1; else { *cbr = '\0'; err += inet_pton(AF_INET6, pat+1, &in6) != 1; } if (slash) *slash = '/'; if (cbr) *cbr = ']'; if (err) tcpd_warn("bad IP6 address specification: %s", pat); #endif } else if (mask = split_at(pat, '/')) { /* network/netmask */ if (dot_quad_addr(pat) == INADDR_NONE || dot_quad_addr(mask) == INADDR_NONE) tcpd_warn("%s/%s: bad net/mask pattern", pat, mask); } else if (STR_EQ(pat, "FAIL")) { /* obsolete */ tcpd_warn("FAIL is no longer recognized"); tcpd_warn("(use EXCEPT or DENY instead)"); } else if (reserved_name(pat)) { /* other reserved */ /* void */ ; } else if (NOT_INADDR(pat)) { /* internet name */ if (pat[strlen(pat) - 1] == '.') { tcpd_warn("%s: domain or host name ends in dot", pat); } else if (pat[0] != '.') { addr_count = check_dns(pat); } } else { /* numeric form */ if (STR_EQ(pat, "0.0.0.0") || STR_EQ(pat, "255.255.255.255")) { /* void */ ; } else if (pat[0] == '.') { tcpd_warn("%s: network number begins with dot", pat); } else if (pat[strlen(pat) - 1] != '.') { check_dns(pat); } } return (addr_count); } /* reserved_name - determine if name is reserved */ static int reserved_name(pat) char *pat; { return (STR_EQ(pat, unknown) || STR_EQ(pat, "KNOWN") || STR_EQ(pat, paranoid) || STR_EQ(pat, "ALL") || STR_EQ(pat, "LOCAL")); }