X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/preload-hacks/blobdiff_plain/006dd63ff8db254b115463150da95de33fd352fa..9111857cc67644ff89749d5919647b38033bb6fd:/noip.c diff --git a/noip.c b/noip.c index 423822d..345f325 100644 --- a/noip.c +++ b/noip.c @@ -57,10 +57,19 @@ #include #include +#ifndef SUN_LEN +# define SUN_LEN (sun) \ + (strlen((sun)->sun_path) + offsetof(struct sockaddr_un, sun_path)) +#endif + /*----- Data structures ---------------------------------------------------*/ -enum { UNUSED, STALE, USED }; /* Unix socket status values */ -enum { WANT_FRESH, WANT_EXISTING }; /* Socket address dispositions */ +/* Unix socket status values. */ +#define UNUSED 0u /* No sign of anyone using it */ +#define STALE 1u /* Socket exists, but is abandoned */ +#define USED 16u /* Socket is in active use */ +#define LISTEN 2u /* Socket has an active listener */ + enum { DENY, ALLOW }; /* ACL verdicts */ static int address_families[] = { AF_INET, AF_INET6, -1 }; @@ -89,6 +98,14 @@ typedef struct aclnode { unsigned short minport, maxport; } aclnode; +/* Implicit bind records */ +typedef struct impbind { + struct impbind *next; + int af, how; + ipaddr minaddr, maxaddr, bindaddr; +} impbind; +enum { EXPLICIT, SAME }; + /* A type for an address range */ typedef struct addrrange { int type; @@ -116,6 +133,7 @@ static unsigned minautoport = 16384, maxautoport = 65536; /* Access control lists */ static aclnode *bind_real, **bind_tail = &bind_real; static aclnode *connect_real, **connect_tail = &connect_real; +static impbind *impbinds, **impbind_tail = &impbinds; /*----- Import the real versions of functions -----------------------------*/ @@ -309,11 +327,65 @@ static void ipaddr_from_sockaddr(ipaddr *a, const struct sockaddr *sa) } } +/* Store the address A in SA. */ +static void ipaddr_to_sockaddr(struct sockaddr *sa, const ipaddr *a) +{ + switch (sa->sa_family) { + case AF_INET: + SIN(sa)->sin_addr = a->v4; + break; + case AF_INET6: + SIN6(sa)->sin6_addr = a->v6; + SIN6(sa)->sin6_scope_id = 0; + SIN6(sa)->sin6_flowinfo = 0; + break; + default: + abort(); + } +} + /* Copy a whole socket address about. */ static void copy_sockaddr(struct sockaddr *sa_dst, const struct sockaddr *sa_src) { memcpy(sa_dst, sa_src, family_socklen(sa_src->sa_family)); } +/* Convert an AF_INET socket address into the equivalent IPv4-mapped AF_INET6 + * address. + */ +static void map_ipv4_sockaddr(struct sockaddr_in6 *a6, + const struct sockaddr_in *a4) +{ + size_t i; + in_addr_t a = ntohl(a4->sin_addr.s_addr); + + a6->sin6_family = AF_INET6; + a6->sin6_port = a4->sin_port; + a6->sin6_scope_id = 0; + a6->sin6_flowinfo = 0; + for (i = 0; i < 10; i++) a6->sin6_addr.s6_addr[i] = 0; + for (i = 10; i < 12; i++) a6->sin6_addr.s6_addr[i] = 0xff; + for (i = 0; i < 4; i++) a6->sin6_addr.s6_addr[15 - i] = (a >> 8*i)&0xff; +} + +/* Convert an AF_INET6 socket address containing an IPv4-mapped IPv6 address + * into the equivalent AF_INET4 address. Return zero on success, or -1 if + * the address has the wrong form. + */ +static int unmap_ipv4_sockaddr(struct sockaddr_in *a4, + const struct sockaddr_in6 *a6) +{ + size_t i; + in_addr_t a; + + for (i = 0; i < 10; i++) if (a6->sin6_addr.s6_addr[i] != 0) return (-1); + for (i = 10; i < 12; i++) if (a6->sin6_addr.s6_addr[i] != 0xff) return (-1); + for (i = 0, a = 0; i < 4; i++) a |= a6->sin6_addr.s6_addr[15 - i] << 8*i; + a4->sin_family = AF_INET; + a4->sin_port = a6->sin6_port; + a4->sin_addr.s_addr = htonl(a); + return (0); +} + /* Answer whether two addresses are equal. */ static int ipaddr_equal_p(int af, const ipaddr *a, const ipaddr *b) { @@ -571,7 +643,8 @@ static int acl_allows_p(const aclnode *a, const struct sockaddr *sa) present_sockaddr(sa, 0, buf, sizeof(buf))); }) for (; a; a = a->next) { D( dump_aclnode(a); ) - if (sockaddr_in_range_p(sa, &a->minaddr, &a->maxaddr) && + if (a->af == sa->sa_family && + sockaddr_in_range_p(sa, &a->minaddr, &a->maxaddr) && a->minport <= port && port <= a->maxport) { D( fprintf(stderr, "noip(%d): aha! %s\n", pid, a->act ? "ALLOW" : "DENY"); ) @@ -613,28 +686,65 @@ static int unix_socket_status(struct sockaddr_un *sun, int quickp) FILE *fp = 0; size_t len, n; int rc; + unsigned long f; char buf[256]; + /* If we can't find the socket node, then it's definitely not in use. If + * we get some other error, then this socket is weird. + */ if (stat(sun->sun_path, &st)) return (errno == ENOENT ? UNUSED : USED); + + /* If it's not a socket, then something weird is going on. If we're just + * probing quickly to find a spare port, then existence is sufficient to + * discourage us now. + */ if (!S_ISSOCK(st.st_mode) || quickp) return (USED); + + /* The socket's definitely there, but is anyone actually still holding it + * open? The only way I know to discover this is to trundle through + * `/proc/net/unix'. If there's no entry, then the socket must be stale. + */ rc = USED; if ((fp = fopen("/proc/net/unix", "r")) == 0) goto done; if (!fgets(buf, sizeof(buf), fp)) goto done; /* skip header */ len = strlen(sun->sun_path); + rc = 0; while (fgets(buf, sizeof(buf), fp)) { n = strlen(buf); if (n >= len + 2 && buf[n - len - 2] == ' ' && buf[n - 1] == '\n' && - memcmp(buf + n - len - 1, sun->sun_path, len) == 0) - goto done; + memcmp(buf + n - len - 1, sun->sun_path, len) == 0) { + rc |= USED; + if (sscanf(buf, "%*s %*x %*x %lx", &f) < 0 || (f&0x00010000)) + rc |= LISTEN; + } } if (ferror(fp)) goto done; - rc = STALE; + if (!rc) rc = STALE; done: if (fp) fclose(fp); + + /* All done. */ + return (rc); +} + +/* Encode SA as a Unix-domain address SUN, and return whether it's currently + * in use. + */ +static int encode_single_inet_addr(const struct sockaddr *sa, + struct sockaddr_un *sun, + int quickp) +{ + char buf[ADDRBUFSZ]; + int rc; + + snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, + present_sockaddr(sa, 0, buf, sizeof(buf))); + rc = unix_socket_status(sun, quickp); + if (rc == STALE) unlink(sun->sun_path); return (rc); } @@ -646,75 +756,155 @@ static int encode_unused_inet_addr(struct sockaddr *sa, struct sockaddr_un *sun, int desperatep) { - address waddr; + address waddr, maddr; struct sockaddr_un wsun; - int rc; - char buf[ADDRBUFSZ]; + int port = port_from_sockaddr(sa); - snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, - present_sockaddr(sa, 0, buf, sizeof(buf))); - if ((rc = unix_socket_status(sun, !desperatep)) == USED) return (-1); - else if (rc == STALE) unlink(sun->sun_path); + /* First, look for an exact match. Only look quickly unless we're + * desperate. If the socket is in use, we fail here. (This could get + * racy. Let's not worry about that for now.) + */ + if (encode_single_inet_addr(sa, sun, !desperatep)&USED) + return (-1); + /* Next, check the corresponding wildcard address, so as to avoid + * inadvertant collisions with listeners. Do this in the same way. + */ wildcard_address(sa->sa_family, &waddr.sa); - port_to_sockaddr(&waddr.sa, port_from_sockaddr(sa)); - snprintf(wsun.sun_path, sizeof(wsun.sun_path), "%s/%s", sockdir, - present_sockaddr(&waddr.sa, 0, buf, sizeof(buf))); - if ((rc = unix_socket_status(&wsun, !desperatep)) == USED) return (-1); - else if (rc == STALE) unlink(wsun.sun_path); + port_to_sockaddr(&waddr.sa, port); + if (encode_single_inet_addr(&waddr.sa, &wsun, !desperatep)&USED) + return (-1); + + /* We're not done yet. If this is an IPv4 address, then /also/ check (a) + * the v6-mapped version, (b) the v6-mapped v4 wildcard, /and/ (c) the v6 + * wildcard. Ugh! + */ + if (sa->sa_family == AF_INET) { + map_ipv4_sockaddr(&maddr.sin6, SIN(&sa)); + if (encode_single_inet_addr(&maddr.sa, &wsun, !desperatep)&USED) + return (-1); + + map_ipv4_sockaddr(&maddr.sin6, &waddr.sin); + if (encode_single_inet_addr(&maddr.sa, &wsun, !desperatep)&USED) + return (-1); + wildcard_address(AF_INET6, &waddr.sa); + port_to_sockaddr(&waddr.sa, port); + if (encode_single_inet_addr(&waddr.sa, &wsun, !desperatep)&USED) + return (-1); + } + + /* All is well. */ return (0); } -/* Encode the Internet address SA as a Unix-domain address SUN. If WANT is - * WANT_FRESH, and SA's port number is zero, then we pick an arbitrary local - * port. Otherwise we pick the port given. There's an unpleasant hack to - * find servers bound to local wildcard addresses. Returns zero on success; - * -1 on failure. +/* Encode the Internet address SA as a Unix-domain address SUN. If the flag + * `ENCF_FRESH' is set, and SA's port number is zero, then we pick an + * arbitrary local port. Otherwise we pick the port given. There's an + * unpleasant hack to find servers bound to local wildcard addresses. + * Returns zero on success; -1 on failure. */ +#define ENCF_FRESH 1u +#define ENCF_REUSEADDR 2u static int encode_inet_addr(struct sockaddr_un *sun, const struct sockaddr *sa, - int want) + unsigned f) { int i; int desperatep = 0; address addr; - char buf[ADDRBUFSZ]; + struct sockaddr_in6 sin6; + int port = port_from_sockaddr(sa); int rc; + char buf[ADDRBUFSZ]; D( fprintf(stderr, "noip(%d): encode %s (%s)", getpid(), present_sockaddr(sa, 0, buf, sizeof(buf)), - want == WANT_EXISTING ? "EXISTING" : "FRESH"); ) + (f&ENCF_FRESH) ? "FRESH" : "EXISTING"); ) + + /* Start making the Unix-domain address. */ sun->sun_family = AF_UNIX; - if (port_from_sockaddr(sa) || want == WANT_EXISTING) { - snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, - present_sockaddr(sa, 0, buf, sizeof(buf))); - rc = unix_socket_status(sun, 0); - if (rc == STALE) unlink(sun->sun_path); - if (rc != USED && want == WANT_EXISTING) { - wildcard_address(sa->sa_family, &addr.sa); - port_to_sockaddr(&addr.sa, port_from_sockaddr(sa)); - snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, - present_sockaddr(&addr.sa, 0, buf, sizeof(buf))); - if (unix_socket_status(sun, 0) == STALE) unlink(sun->sun_path); + + if (port || !(f&ENCF_FRESH)) { + + /* Try the address as given. If it's in use, or we don't necessarily + * want an existing socket, then we're done. + */ + rc = encode_single_inet_addr(sa, sun, 0); + if ((f&ENCF_REUSEADDR) && !(rc&LISTEN)) unlink(sun->sun_path); + if ((rc&USED) || (f&ENCF_FRESH)) goto found; + + /* We're looking for a socket which already exists. This is + * unfortunately difficult, because we must deal both with wildcards and + * v6-mapped IPv4 addresses. + * + * * We've just tried searching for a socket whose name is an exact + * match for our remote address. If the remote address is IPv4, then + * we should try again with the v6-mapped equivalent. + * + * * Failing that, we try again with the wildcard address for the + * appropriate address family. + * + * * Failing /that/, if the remote address is IPv4, then we try + * /again/, increasingly desperately, first with the v6-mapped IPv4 + * wildcard address, and then with the IPv6 wildcard address. This + * will cause magic v6-mapping to occur when the connection is + * accepted, which we hope won't cause too much trouble. + */ + + if (sa->sa_family == AF_INET) { + map_ipv4_sockaddr(&addr.sin6, SIN(sa)); + if (encode_single_inet_addr(&addr.sa, sun, 0)&USED) goto found; } + + wildcard_address(sa->sa_family, &addr.sa); + port_to_sockaddr(&addr.sa, port); + if (encode_single_inet_addr(&addr.sa, sun, 0)&USED) goto found; + + if (sa->sa_family == AF_INET) { + map_ipv4_sockaddr(&sin6, &addr.sin); + if (encode_single_inet_addr(SA(&sin6), sun, 0)&USED) goto found; + wildcard_address(AF_INET6, &addr.sa); + port_to_sockaddr(&addr.sa, port); + if (encode_single_inet_addr(&addr.sa, sun, 0)&USED) goto found; + } + + /* Well, this isn't going to work (unless a miraculous race is lost), but + * we might as well try. + */ + encode_single_inet_addr(sa, sun, 1); + } else { + /* We want a fresh new socket. */ + + /* Make a copy of the given address, because we're going to mangle it. */ copy_sockaddr(&addr.sa, sa); + + /* Try a few random-ish port numbers to see if any of them is spare. */ for (i = 0; i < 10; i++) { port_to_sockaddr(&addr.sa, randrange(minautoport, maxautoport)); if (!encode_unused_inet_addr(&addr.sa, sun, 0)) goto found; } + + /* Things must be getting tight. Work through all of the autoport range + * to see if we can find a spare one. The first time, just do it the + * quick way; if that doesn't work, then check harder for stale sockets. + */ for (desperatep = 0; desperatep < 2; desperatep++) { for (i = minautoport; i <= maxautoport; i++) { port_to_sockaddr(&addr.sa, i); if (!encode_unused_inet_addr(&addr.sa, sun, 0)) goto found; } } + + /* We failed to find any free ports. */ errno = EADDRINUSE; D( fprintf(stderr, " -- can't resolve\n"); ) return (-1); - found:; } + + /* Success. */ +found: D( fprintf(stderr, " -> `%s'\n", sun->sun_path); ) return (0); } @@ -825,50 +1015,30 @@ static int fixup_real_ip_socket(int sk, int af_hint, int *tmp) return (0); } -/* The socket SK is about to be used to communicate with the remote address - * SA. Assign it a local address so that getpeername(2) does something - * useful. - */ -static int do_implicit_bind(int sk, const struct sockaddr **sa, - socklen_t *len, struct sockaddr_un *sun) -{ - address addr; - socklen_t mylen = sizeof(*sun); - - if (acl_allows_p(connect_real, *sa)) { - if (fixup_real_ip_socket(sk, (*sa)->sa_family, 0)) return (-1); - } else { - if (real_getsockname(sk, SA(sun), &mylen) < 0) return (-1); - if (sun->sun_family == AF_UNIX) { - if (mylen < sizeof(*sun)) ((char *)sun)[mylen] = 0; - if (!sun->sun_path[0]) { - wildcard_address((*sa)->sa_family, &addr.sa); - encode_inet_addr(sun, &addr.sa, WANT_FRESH); - if (real_bind(sk, SA(sun), SUN_LEN(sun))) return (-1); - } - encode_inet_addr(sun, *sa, WANT_EXISTING); - *sa = SA(sun); - *len = SUN_LEN(sun); - } - } - return (0); -} - /* We found the real address SA, with length LEN; if it's a Unix-domain * address corresponding to a fake socket, convert it to cover up the * deception. Whatever happens, put the result at FAKE and store its length * at FAKELEN. */ +#define FNF_V6MAPPED 1u static void return_fake_name(struct sockaddr *sa, socklen_t len, - struct sockaddr *fake, socklen_t *fakelen) + struct sockaddr *fake, socklen_t *fakelen, + unsigned f) { address addr; + struct sockaddr_in6 sin6; socklen_t alen; if (sa->sa_family == AF_UNIX && !decode_inet_addr(&addr.sa, 0, SUN(sa), len)) { - sa = &addr.sa; - len = family_socklen(addr.sa.sa_family); + if (addr.sa.sa_family != AF_INET || !(f&FNF_V6MAPPED)) { + sa = &addr.sa; + len = family_socklen(addr.sa.sa_family); + } else { + map_ipv4_sockaddr(&sin6, &addr.sin); + sa = SA(&sin6); + len = family_socklen(AF_INET6); + } } alen = len; if (len > *fakelen) len = *fakelen; @@ -876,6 +1046,156 @@ static void return_fake_name(struct sockaddr *sa, socklen_t len, *fakelen = alen; } +/* Variant of `return_fake_name' above, specifically handling the weirdness + * of remote v6-mapped IPv4 addresses. If SK's fake local address is IPv6, + * and the remote address is IPv4, then return a v6-mapped version of the + * remote address. + */ +static void return_fake_peer(int sk, struct sockaddr *sa, socklen_t len, + struct sockaddr *fake, socklen_t *fakelen) +{ + char sabuf[1024]; + socklen_t mylen = sizeof(sabuf); + unsigned fnf = 0; + address addr; + int rc; + + PRESERVING_ERRNO({ + rc = real_getsockname(sk, SA(sabuf), &mylen); + if (!rc && sa->sa_family == AF_UNIX && + !decode_inet_addr(&addr.sa, 0, SUN(sabuf), mylen) && + addr.sa.sa_family == AF_INET6) + fnf |= FNF_V6MAPPED; + }); + return_fake_name(sa, len, fake, fakelen, fnf); +} + +/*----- Implicit binding --------------------------------------------------*/ + +#ifdef DEBUG + +static void dump_impbind(const impbind *i) +{ + char buf[ADDRBUFSZ]; + + fprintf(stderr, "noip(%d): ", getpid()); + dump_addrrange(i->af, &i->minaddr, &i->maxaddr); + switch (i->how) { + case SAME: fprintf(stderr, " "); break; + case EXPLICIT: + fprintf(stderr, " %s", inet_ntop(i->af, &i->bindaddr, + buf, sizeof(buf))); + break; + default: abort(); + } + fputc('\n', stderr); +} + +static void dump_impbind_list(void) +{ + const impbind *i; + + for (i = impbinds; i; i = i->next) dump_impbind(i); +} + +#endif + +/* The socket SK is about to be used to communicate with the remote address + * SA. Assign it a local address so that getpeername(2) does something + * useful. + * + * If the flag `IBF_V6MAPPED' is set then, then SA must be an `AF_INET' + * address; after deciding on the appropriate local address, convert it to be + * an IPv4-mapped IPv6 address before final conversion to a Unix-domain + * socket address and actually binding. Note that this could well mean that + * the socket ends up bound to the v6-mapped v4 wildcard address + * ::ffff:0.0.0.0, which looks very strange but is meaningful. + */ +#define IBF_V6MAPPED 1u +static int do_implicit_bind(int sk, const struct sockaddr *sa, unsigned f) +{ + address addr; + struct sockaddr_in6 sin6; + struct sockaddr_un sun; + const impbind *i; + Dpid; + + D( fprintf(stderr, "noip(%d): checking impbind list...\n", pid); ) + for (i = impbinds; i; i = i->next) { + D( dump_impbind(i); ) + if (sa->sa_family == i->af && + sockaddr_in_range_p(sa, &i->minaddr, &i->maxaddr)) { + D( fprintf(stderr, "noip(%d): match!\n", pid); ) + addr.sa.sa_family = sa->sa_family; + switch (i->how) { + case EXPLICIT: ipaddr_to_sockaddr(&addr.sa, &i->bindaddr); break; + case SAME: copy_sockaddr(&addr.sa, sa); break; + } + port_to_sockaddr(&addr.sa, 0); + goto found; + } + } + D( fprintf(stderr, "noip(%d): no match; using wildcard\n", pid); ) + wildcard_address(sa->sa_family, &addr.sa); +found: + if (addr.sa.sa_family != AF_INET || !(f&IBF_V6MAPPED)) sa = &addr.sa; + else { map_ipv4_sockaddr(&sin6, &addr.sin); sa = SA(&sin6); } + encode_inet_addr(&sun, sa, ENCF_FRESH); + D( fprintf(stderr, "noip(%d): implicitly binding to %s\n", + pid, sun.sun_path); ) + if (real_bind(sk, SA(&sun), SUN_LEN(&sun))) return (-1); + return (0); +} + +/* The socket SK is about to communicate with the remote address *SA. Ensure + * that the socket has a local address, and adjust *SA to refer to the real + * remote endpoint. + * + * If we need to translate the remote address, then the Unix-domain endpoint + * address will end in *SUN, and *SA will be adjusted to point to it. + */ +static int fixup_client_socket(int sk, const struct sockaddr **sa_r, + socklen_t *len_r, struct sockaddr_un *sun) +{ + struct sockaddr_in sin; + socklen_t mylen = sizeof(*sun); + const struct sockaddr *sa = *sa_r; + unsigned ibf = 0; + + /* If this isn't a Unix-domain socket then there's nothing to do. */ + if (real_getsockname(sk, SA(sun), &mylen) < 0) return (-1); + if (sun->sun_family != AF_UNIX) return (0); + if (mylen < sizeof(*sun)) ((char *)sun)[mylen] = 0; + + /* If the remote address is v6-mapped IPv4, then unmap it so as to search + * for IPv4 servers. Also remember to v6-map the local address when we + * autobind. + */ + if (sa->sa_family == AF_INET6 && !(unmap_ipv4_sockaddr(&sin, SIN6(sa)))) { + sa = SA(&sin); + ibf |= IBF_V6MAPPED; + } + + /* If we're allowed to talk to a real remote endpoint, then fix things up + * as necessary and proceed. + */ + if (acl_allows_p(connect_real, sa)) { + if (fixup_real_ip_socket(sk, (*sa_r)->sa_family, 0)) return (-1); + return (0); + } + + /* Speaking of which, if we don't have a local address, then we should + * arrange one now. + */ + if (!sun->sun_path[0] && do_implicit_bind(sk, sa, ibf)) return (-1); + + /* And then come up with a remote address. */ + encode_inet_addr(sun, sa, 0); + *sa_r = SA(sun); + *len_r = SUN_LEN(sun); + return (0); +} + /*----- Configuration -----------------------------------------------------*/ /* Return the process owner's home directory. */ @@ -1159,6 +1479,82 @@ static void parse_acl_env(const char *var, aclnode ***tail) } } +struct add_impbind_ctx { + int af, how; + ipaddr addr; +}; + +static void add_impbind(int af, const ipaddr *min, const ipaddr *max, + void *p) +{ + struct add_impbind_ctx *ctx = p; + impbind *i; + + if (ctx->af && af != ctx->af) return; + NEW(i); + i->af = af; + i->how = ctx->how; + i->minaddr = *min; i->maxaddr = *max; + switch (ctx->how) { + case EXPLICIT: i->bindaddr = ctx->addr; + case SAME: break; + default: abort(); + } + *impbind_tail = i; impbind_tail = &i->next; +} + +/* Parse an implicit-bind line. An implicit-bind entry has the form + * ADDR-RANGE {ADDR | same} + */ +static void parse_impbind_line(char **pp) +{ + struct add_impbind_ctx ctx; + char *p = *pp, *q; + addrrange r; + int del; + + for (;;) { + if (parse_addrrange(&p, &r)) goto bad; + SKIPSPC; + if (KWMATCHP("same")) { + ctx.how = SAME; + ctx.af = 0; + } else { + ctx.how = EXPLICIT; + parse_nextaddr(&p, &q, &del); + ctx.af = guess_address_family(q); + if (inet_pton(ctx.af, q, &ctx.addr) < 0) goto bad; + RESCAN(del); + } + foreach_addrrange(&r, add_impbind, &ctx); + SKIPSPC; + if (*p != ',') break; + if (*p) p++; + } + if (*p) goto bad; + *pp = p; + return; + +bad: + D( fprintf(stderr, "noip(%d): bad implicit-bind spec (ignored)\n", + getpid()); ) + return; +} + +/* Parse implicit-bind instructions from an environment variable VAR, + * attaching it to the list. + */ +static void parse_impbind_env(const char *var) +{ + char *p, *q; + + if ((p = getenv(var)) != 0) { + p = q = xstrdup(p); + parse_impbind_line(&q); + free(p); + } +} + /* Parse the autoports configuration directive. Syntax is MIN - MAX. */ static void parse_autoports(char **pp) { @@ -1169,7 +1565,8 @@ static void parse_autoports(char **pp) SKIPSPC; NEXTNUMBER(q, del); x = strtoul(q, 0, 0); RESCAN(del); SKIPSPC; - if (*p != '-') goto bad; p++; + if (*p != '-') goto bad; + p++; NEXTNUMBER(q, del); y = strtoul(q, 0, 0); RESCAN(del); minautoport = x; maxautoport = y; SKIPSPC; if (*p) goto bad; @@ -1192,6 +1589,7 @@ static void readconfig(void) parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail); parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail); + parse_impbind_env("NOIP_IMPBIND_BEFORE"); if ((p = getenv("NOIP_AUTOPORTS")) != 0) { p = q = xstrdup(p); parse_autoports(&q); @@ -1223,22 +1621,27 @@ static void readconfig(void) parse_acl_line(&p, &bind_tail); else if (strcmp(cmd, "realconnect") == 0) parse_acl_line(&p, &connect_tail); + else if (strcmp(cmd, "impbind") == 0) + parse_impbind_line(&p); else if (strcmp(cmd, "autoports") == 0) parse_autoports(&p); else if (strcmp(cmd, "debug") == 0) debug = *p ? atoi(p) : 1; else - D( fprintf(stderr, "noip: bad config command %s\n", cmd); ) + D( fprintf(stderr, "noip(%d): bad config command %s\n", pid, cmd); ) } fclose(fp); done: parse_acl_env("NOIP_REALBIND", &bind_tail); parse_acl_env("NOIP_REALCONNECT", &connect_tail); + parse_impbind_env("NOIP_IMPBIND"); parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail); parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail); + parse_impbind_env("NOIP_IMPBIND_AFTER"); *bind_tail = 0; *connect_tail = 0; + *impbind_tail = 0; if (!sockdir) sockdir = getenv("NOIP_SOCKETDIR"); if (!sockdir) { snprintf(buf, sizeof(buf), "%s/noip-%s", tmpdir(), user()); @@ -1250,7 +1653,9 @@ done: fprintf(stderr, "noip(%d): realbind acl:\n", pid); dump_acl(bind_real); fprintf(stderr, "noip(%d): realconnect acl:\n", pid); - dump_acl(connect_real); ) + dump_acl(connect_real); + fprintf(stderr, "noip(%d): impbind list:\n", pid); + dump_impbind_list(); ) } /*----- Overridden system calls -------------------------------------------*/ @@ -1329,6 +1734,9 @@ int bind(int sk, const struct sockaddr *sa, socklen_t len) { struct sockaddr_un sun; int rc; + unsigned f; + int reusep; + socklen_t n; Dpid; D({ char buf[ADDRBUFSZ]; @@ -1344,7 +1752,11 @@ int bind(int sk, const struct sockaddr *sa, socklen_t len) if (fixup_real_ip_socket(sk, sa->sa_family, 0)) return (-1); } else { - encode_inet_addr(&sun, sa, WANT_FRESH); + f = ENCF_FRESH; + n = sizeof(reusep); + if (!getsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &reusep, &n) && reusep) + f |= ENCF_REUSEADDR; + encode_inet_addr(&sun, sa, f); sa = SA(&sun); len = SUN_LEN(&sun); } @@ -1372,7 +1784,7 @@ int connect(int sk, const struct sockaddr *sa, socklen_t len) } else { D( fprintf(stderr, " -> checking...\n"); ) PRESERVING_ERRNO({ - do_implicit_bind(sk, &sa, &len, &sun); + fixup_client_socket(sk, &sa, &len, &sun); }); D( fprintf(stderr, "noip(%d): CONNECT ...", pid); ) rc = real_connect(sk, sa, len); @@ -1405,7 +1817,7 @@ ssize_t sendto(int sk, const void *buf, size_t len, int flags, else { D( fprintf(stderr, " -> checking...\n"); ) PRESERVING_ERRNO({ - do_implicit_bind(sk, &to, &tolen, &sun); + fixup_client_socket(sk, &to, &tolen, &sun); }); D( fprintf(stderr, "noip(%d): SENDTO ...", pid); ) } @@ -1429,14 +1841,14 @@ ssize_t recvfrom(int sk, void *buf, size_t len, int flags, D( fprintf(stderr, " -> null addr; pass through"); ) n = real_recvfrom(sk, buf, len, flags, 0, 0); } else { - PRESERVING_ERRNO({ - n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen); - if (n >= 0) { - D( fprintf(stderr, " -> converting...\n"); ) - return_fake_name(SA(sabuf), mylen, from, fromlen); - D( fprintf(stderr, "noip(%d): ... RECVFROM", pid); ) - } - }); + n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen); + if (n >= 0) { + D( fprintf(stderr, " -> converting...\n"); ) + PRESERVING_ERRNO({ + return_fake_peer(sk, SA(sabuf), mylen, from, fromlen); + }); + D( fprintf(stderr, "noip(%d): ... RECVFROM", pid); ) + } } D( dump_addrresult(n, from, fromlen ? *fromlen : 0); ) return (n); @@ -1465,7 +1877,7 @@ ssize_t sendmsg(int sk, const struct msghdr *msg, int flags) D( fprintf(stderr, " -> checking...\n"); ) PRESERVING_ERRNO({ mymsg = *msg; - do_implicit_bind(sk, &sa, &mymsg.msg_namelen, &sun); + fixup_client_socket(sk, &sa, &mymsg.msg_namelen, &sun); mymsg.msg_name = SA(sa); msg = &mymsg; }); @@ -1491,18 +1903,18 @@ ssize_t recvmsg(int sk, struct msghdr *msg, int flags) D( fprintf(stderr, " -> null addr; pass through"); ) return (real_recvmsg(sk, msg, flags)); } else { - PRESERVING_ERRNO({ - msg->msg_name = sabuf; - msg->msg_namelen = sizeof(sabuf); - n = real_recvmsg(sk, msg, flags); - if (n >= 0) { - D( fprintf(stderr, " -> converting...\n"); ) - return_fake_name(SA(sabuf), msg->msg_namelen, sa, &len); - D( fprintf(stderr, "noip(%d): ... RECVMSG", pid); ) - } - msg->msg_name = sa; - msg->msg_namelen = len; - }); + msg->msg_name = sabuf; + msg->msg_namelen = sizeof(sabuf); + n = real_recvmsg(sk, msg, flags); + if (n >= 0) { + D( fprintf(stderr, " -> converting...\n"); ) + PRESERVING_ERRNO({ + return_fake_peer(sk, SA(sabuf), msg->msg_namelen, sa, &len); + }); + } + D( fprintf(stderr, "noip(%d): ... RECVMSG", pid); ) + msg->msg_name = sa; + msg->msg_namelen = len; } D( dump_addrresult(n, sa, len); ) return (n); @@ -1522,7 +1934,7 @@ int accept(int sk, struct sockaddr *sa, socklen_t *len) else if (!sa) D( fprintf(stderr, " -> address not wanted"); ) else { D( fprintf(stderr, " -> converting...\n"); ) - return_fake_name(SA(sabuf), mylen, sa, len); + return_fake_peer(sk, SA(sabuf), mylen, sa, len); D( fprintf(stderr, "noip(%d): ... ACCEPT", pid); ) } D( dump_addrresult(nsk, sa, len ? *len : 0); ) @@ -1531,50 +1943,47 @@ int accept(int sk, struct sockaddr *sa, socklen_t *len) int getsockname(int sk, struct sockaddr *sa, socklen_t *len) { + char sabuf[1024]; + socklen_t mylen = sizeof(sabuf); int rc; Dpid; D( fprintf(stderr, "noip(%d): GETSOCKNAME sk=%d", pid, sk); ) - PRESERVING_ERRNO({ - char sabuf[1024]; - socklen_t mylen = sizeof(sabuf); - rc = real_getsockname(sk, SA(sabuf), &mylen); - if (rc >= 0) { - D( fprintf(stderr, " -> converting...\n"); ) - return_fake_name(SA(sabuf), mylen, sa, len); - D( fprintf(stderr, "noip(%d): ... GETSOCKNAME", pid); ) - } - }); + rc = real_getsockname(sk, SA(sabuf), &mylen); + if (rc >= 0) { + D( fprintf(stderr, " -> converting...\n"); ) + return_fake_name(SA(sabuf), mylen, sa, len, 0); + D( fprintf(stderr, "noip(%d): ... GETSOCKNAME", pid); ) + } D( dump_addrresult(rc, sa, *len); ) return (rc); } int getpeername(int sk, struct sockaddr *sa, socklen_t *len) { + char sabuf[1024]; + socklen_t mylen = sizeof(sabuf); int rc; Dpid; D( fprintf(stderr, "noip(%d): GETPEERNAME sk=%d", pid, sk); ) - PRESERVING_ERRNO({ - char sabuf[1024]; - socklen_t mylen = sizeof(sabuf); - rc = real_getpeername(sk, SA(sabuf), &mylen); - if (rc >= 0) { - D( fprintf(stderr, " -> converting...\n"); ) - return_fake_name(SA(sabuf), mylen, sa, len); - D( fprintf(stderr, "noip(%d): ... GETPEERNAME", pid); ) - } - }); + rc = real_getpeername(sk, SA(sabuf), &mylen); + if (rc >= 0) { + D( fprintf(stderr, " -> converting...\n"); ) + return_fake_peer(sk, SA(sabuf), mylen, sa, len); + D( fprintf(stderr, "noip(%d): ... GETPEERNAME", pid); ) + } D( dump_addrresult(rc, sa, *len); ) - return (0); + return (rc); } int getsockopt(int sk, int lev, int opt, void *p, socklen_t *len) { switch (lev) { - case SOL_IP: - case SOL_TCP: - case SOL_UDP: + case IPPROTO_IP: + case IPPROTO_IPV6: + case IPPROTO_TCP: + case IPPROTO_UDP: if (*len > 0) memset(p, 0, *len); return (0); @@ -1585,9 +1994,10 @@ int getsockopt(int sk, int lev, int opt, void *p, socklen_t *len) int setsockopt(int sk, int lev, int opt, const void *p, socklen_t len) { switch (lev) { - case SOL_IP: - case SOL_TCP: - case SOL_UDP: + case IPPROTO_IP: + case IPPROTO_IPV6: + case IPPROTO_TCP: + case IPPROTO_UDP: return (0); } switch (opt) {