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-rw-r--r--clientname.c410
1 files changed, 295 insertions, 115 deletions
diff --git a/clientname.c b/clientname.c
index 4ac8b485..1e85c84e 100644
--- a/clientname.c
+++ b/clientname.c
@@ -3,7 +3,7 @@
*
* Copyright (C) 1992-2001 Andrew Tridgell <tridge@samba.org>
* Copyright (C) 2001, 2002 Martin Pool <mbp@samba.org>
- * Copyright (C) 2002-2018 Wayne Davison
+ * Copyright (C) 2002-2020 Wayne Davison
*
* 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
@@ -27,52 +27,60 @@
*/
#include "rsync.h"
+#include "itypes.h"
+
+extern int am_daemon;
static const char default_name[] = "UNKNOWN";
-extern int am_server;
+static const char proxyv2sig[] = "\r\n\r\n\0\r\nQUIT\n";
+static char ipaddr_buf[100];
-/**
- * Return the IP addr of the client as a string
- **/
+#define PROXY_V2_SIG_SIZE ((int)sizeof proxyv2sig - 1)
+#define PROXY_V2_HEADER_SIZE (PROXY_V2_SIG_SIZE + 1 + 1 + 2)
+
+#define CMD_LOCAL 0
+#define CMD_PROXY 1
+
+#define PROXY_FAM_TCPv4 0x11
+#define PROXY_FAM_TCPv6 0x21
+
+#define GET_SOCKADDR_FAMILY(ss) ((struct sockaddr*)ss)->sa_family
+
+static void client_sockaddr(int fd, struct sockaddr_storage *ss, socklen_t *ss_len);
+static int check_name(const char *ipaddr, const struct sockaddr_storage *ss, char *name_buf, size_t name_buf_size);
+static int valid_ipaddr(const char *s);
+
+/* Return the IP addr of the client as a string. */
char *client_addr(int fd)
{
- static char addr_buf[100];
- static int initialised;
struct sockaddr_storage ss;
socklen_t length = sizeof ss;
- if (initialised)
- return addr_buf;
+ if (*ipaddr_buf)
+ return ipaddr_buf;
- initialised = 1;
-
- if (am_server) { /* daemon over --rsh mode */
+ if (am_daemon < 0) { /* daemon over --rsh mode */
char *env_str;
- strlcpy(addr_buf, "0.0.0.0", sizeof addr_buf);
+ strlcpy(ipaddr_buf, "0.0.0.0", sizeof ipaddr_buf);
if ((env_str = getenv("REMOTE_HOST")) != NULL
|| (env_str = getenv("SSH_CONNECTION")) != NULL
|| (env_str = getenv("SSH_CLIENT")) != NULL
|| (env_str = getenv("SSH2_CLIENT")) != NULL) {
char *p;
- strlcpy(addr_buf, env_str, sizeof addr_buf);
+ strlcpy(ipaddr_buf, env_str, sizeof ipaddr_buf);
/* Truncate the value to just the IP address. */
- if ((p = strchr(addr_buf, ' ')) != NULL)
+ if ((p = strchr(ipaddr_buf, ' ')) != NULL)
*p = '\0';
}
- } else {
- client_sockaddr(fd, &ss, &length);
- getnameinfo((struct sockaddr *)&ss, length,
- addr_buf, sizeof addr_buf, NULL, 0, NI_NUMERICHOST);
+ if (valid_ipaddr(ipaddr_buf))
+ return ipaddr_buf;
}
- return addr_buf;
-}
+ client_sockaddr(fd, &ss, &length);
+ getnameinfo((struct sockaddr *)&ss, length, ipaddr_buf, sizeof ipaddr_buf, NULL, 0, NI_NUMERICHOST);
-
-static int get_sockaddr_family(const struct sockaddr_storage *ss)
-{
- return ((struct sockaddr *) ss)->sa_family;
+ return ipaddr_buf;
}
@@ -89,71 +97,216 @@ static int get_sockaddr_family(const struct sockaddr_storage *ss)
* After translation from sockaddr to name we do a forward lookup to
* make sure nobody is spoofing PTR records.
**/
-char *client_name(int fd)
+char *client_name(const char *ipaddr)
{
static char name_buf[100];
- static char port_buf[100];
- static int initialised;
+ char port_buf[100];
struct sockaddr_storage ss;
socklen_t ss_len;
+ struct addrinfo hint, *answer;
+ int err;
- if (initialised)
+ if (*name_buf)
return name_buf;
strlcpy(name_buf, default_name, sizeof name_buf);
- initialised = 1;
-
- memset(&ss, 0, sizeof ss);
-
- if (am_server) { /* daemon over --rsh mode */
- char *addr = client_addr(fd);
- struct addrinfo hint, *answer;
- int err;
- if (strcmp(addr, "0.0.0.0") == 0)
- return name_buf;
+ if (strcmp(ipaddr, "0.0.0.0") == 0)
+ return name_buf;
- memset(&hint, 0, sizeof hint);
+ memset(&ss, 0, sizeof ss);
+ memset(&hint, 0, sizeof hint);
#ifdef AI_NUMERICHOST
- hint.ai_flags = AI_NUMERICHOST;
+ hint.ai_flags = AI_NUMERICHOST;
#endif
- hint.ai_socktype = SOCK_STREAM;
+ hint.ai_socktype = SOCK_STREAM;
- if ((err = getaddrinfo(addr, NULL, &hint, &answer)) != 0) {
- rprintf(FLOG, "malformed address %s: %s\n",
- addr, gai_strerror(err));
- return name_buf;
- }
+ if ((err = getaddrinfo(ipaddr, NULL, &hint, &answer)) != 0) {
+ rprintf(FLOG, "malformed address %s: %s\n", ipaddr, gai_strerror(err));
+ return name_buf;
+ }
- switch (answer->ai_family) {
- case AF_INET:
- ss_len = sizeof (struct sockaddr_in);
- memcpy(&ss, answer->ai_addr, ss_len);
- break;
+ switch (answer->ai_family) {
+ case AF_INET:
+ ss_len = sizeof (struct sockaddr_in);
+ memcpy(&ss, answer->ai_addr, ss_len);
+ break;
#ifdef INET6
- case AF_INET6:
- ss_len = sizeof (struct sockaddr_in6);
- memcpy(&ss, answer->ai_addr, ss_len);
- break;
+ case AF_INET6:
+ ss_len = sizeof (struct sockaddr_in6);
+ memcpy(&ss, answer->ai_addr, ss_len);
+ break;
#endif
- default:
- exit_cleanup(RERR_SOCKETIO);
- }
- freeaddrinfo(answer);
- } else {
- ss_len = sizeof ss;
- client_sockaddr(fd, &ss, &ss_len);
+ default:
+ assert(0);
}
+ freeaddrinfo(answer);
- if (lookup_name(fd, &ss, ss_len, name_buf, sizeof name_buf,
- port_buf, sizeof port_buf) == 0)
- check_name(fd, &ss, name_buf, sizeof name_buf);
+ /* reverse lookup */
+ err = getnameinfo((struct sockaddr*)&ss, ss_len, name_buf, sizeof name_buf,
+ port_buf, sizeof port_buf, NI_NAMEREQD | NI_NUMERICSERV);
+ if (err) {
+ strlcpy(name_buf, default_name, sizeof name_buf);
+ rprintf(FLOG, "name lookup failed for %s: %s\n", ipaddr, gai_strerror(err));
+ } else
+ check_name(ipaddr, &ss, name_buf, sizeof name_buf);
return name_buf;
}
+/* Try to read an proxy protocol header (V1 or V2). Returns 1 on success or 0 on failure. */
+int read_proxy_protocol_header(int fd)
+{
+ union {
+ struct {
+ char line[108];
+ } v1;
+ struct {
+ char sig[PROXY_V2_SIG_SIZE];
+ char ver_cmd;
+ char fam;
+ char len[2];
+ union {
+ struct {
+ char src_addr[4];
+ char dst_addr[4];
+ char src_port[2];
+ char dst_port[2];
+ } ip4;
+ struct {
+ char src_addr[16];
+ char dst_addr[16];
+ char src_port[2];
+ char dst_port[2];
+ } ip6;
+ struct {
+ char src_addr[108];
+ char dst_addr[108];
+ } unx;
+ } addr;
+ } v2;
+ } hdr;
+
+ read_buf(fd, (char*)&hdr, PROXY_V2_SIG_SIZE);
+
+ if (memcmp(hdr.v2.sig, proxyv2sig, PROXY_V2_SIG_SIZE) == 0) { /* Proxy V2 */
+ int ver, cmd, size;
+
+ read_buf(fd, (char*)&hdr + PROXY_V2_SIG_SIZE, PROXY_V2_HEADER_SIZE - PROXY_V2_SIG_SIZE);
+
+ ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
+ cmd = (hdr.v2.ver_cmd & 0x0f);
+ size = (hdr.v2.len[0] << 8) + hdr.v2.len[1];
+
+ if (ver != 2 || size + PROXY_V2_HEADER_SIZE > (int)sizeof hdr)
+ return 0;
+
+ /* Grab all the remaining data in the binary request. */
+ read_buf(fd, (char*)&hdr + PROXY_V2_HEADER_SIZE, size);
+
+ switch (cmd) {
+ case CMD_PROXY:
+ switch (hdr.v2.fam) {
+ case PROXY_FAM_TCPv4:
+ if (size != sizeof hdr.v2.addr.ip4)
+ return 0;
+ inet_ntop(AF_INET, hdr.v2.addr.ip4.src_addr, ipaddr_buf, sizeof ipaddr_buf);
+ return valid_ipaddr(ipaddr_buf);
+ case PROXY_FAM_TCPv6:
+ if (size != sizeof hdr.v2.addr.ip6)
+ return 0;
+ inet_ntop(AF_INET6, hdr.v2.addr.ip6.src_addr, ipaddr_buf, sizeof ipaddr_buf);
+ return valid_ipaddr(ipaddr_buf);
+ default:
+ break;
+ }
+ /* For an unsupported protocol we'll ignore the proxy data (leaving ipaddr_buf unset)
+ * and accept the connection, which will get handled as a normal socket addr. */
+ return 1;
+ case CMD_LOCAL:
+ return 1;
+ default:
+ break;
+ }
+
+ return 0;
+ }
+
+ if (memcmp(hdr.v1.line, "PROXY", 5) == 0) { /* Proxy V1 */
+ char *endc, *sp, *p = hdr.v1.line + PROXY_V2_SIG_SIZE;
+ int port_chk;
+
+ *p = '\0';
+ if (!strchr(hdr.v1.line, '\n')) {
+ while (1) {
+ read_buf(fd, p, 1);
+ if (*p++ == '\n')
+ break;
+ if (p - hdr.v1.line >= (int)sizeof hdr.v1.line - 1)
+ return 0;
+ }
+ *p = '\0';
+ }
+
+ endc = strchr(hdr.v1.line, '\r');
+ if (!endc || endc[1] != '\n' || endc[2])
+ return 0;
+ *endc = '\0';
+
+ p = hdr.v1.line + 5;
+
+ if (!isSpace(p++))
+ return 0;
+ if (strncmp(p, "TCP4", 4) == 0)
+ p += 4;
+ else if (strncmp(p, "TCP6", 4) == 0)
+ p += 4;
+ else if (strncmp(p, "UNKNOWN", 7) == 0)
+ return 1;
+ else
+ return 0;
+
+ if (!isSpace(p++))
+ return 0;
+
+ if ((sp = strchr(p, ' ')) == NULL)
+ return 0;
+ *sp = '\0';
+ if (!valid_ipaddr(p))
+ return 0;
+ strlcpy(ipaddr_buf, p, sizeof ipaddr_buf); /* It will always fit when valid. */
+
+ p = sp + 1;
+ if ((sp = strchr(p, ' ')) == NULL)
+ return 0;
+ *sp = '\0';
+ if (!valid_ipaddr(p))
+ return 0;
+ /* Ignore destination address. */
+
+ p = sp + 1;
+ if ((sp = strchr(p, ' ')) == NULL)
+ return 0;
+ *sp = '\0';
+ port_chk = strtol(p, &endc, 10);
+ if (*endc || port_chk == 0)
+ return 0;
+ /* Ignore source port. */
+
+ p = sp + 1;
+ port_chk = strtol(p, &endc, 10);
+ if (*endc || port_chk == 0)
+ return 0;
+ /* Ignore destination port. */
+
+ return 1;
+ }
+
+ return 0;
+}
+
/**
* Get the sockaddr for the client.
@@ -161,9 +314,7 @@ char *client_name(int fd)
* If it comes in as an ipv4 address mapped into IPv6 format then we
* convert it back to a regular IPv4.
**/
-void client_sockaddr(int fd,
- struct sockaddr_storage *ss,
- socklen_t *ss_len)
+static void client_sockaddr(int fd, struct sockaddr_storage *ss, socklen_t *ss_len)
{
memset(ss, 0, sizeof *ss);
@@ -174,8 +325,8 @@ void client_sockaddr(int fd,
}
#ifdef INET6
- if (get_sockaddr_family(ss) == AF_INET6 &&
- IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)ss)->sin6_addr)) {
+ if (GET_SOCKADDR_FAMILY(ss) == AF_INET6
+ && IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)ss)->sin6_addr)) {
/* OK, so ss is in the IPv6 family, but it is really
* an IPv4 address: something like
* "::ffff:10.130.1.2". If we use it as-is, then the
@@ -198,51 +349,20 @@ void client_sockaddr(int fd,
/* There is a macro to extract the mapped part
* (IN6_V4MAPPED_TO_SINADDR ?), but it does not seem
* to be present in the Linux headers. */
- memcpy(&sin->sin_addr, &sin6.sin6_addr.s6_addr[12],
- sizeof sin->sin_addr);
+ memcpy(&sin->sin_addr, &sin6.sin6_addr.s6_addr[12], sizeof sin->sin_addr);
}
#endif
}
/**
- * Look up a name from @p ss into @p name_buf.
- *
- * @param fd file descriptor for client socket.
- **/
-int lookup_name(int fd, const struct sockaddr_storage *ss,
- socklen_t ss_len,
- char *name_buf, size_t name_buf_size,
- char *port_buf, size_t port_buf_size)
-{
- int name_err;
-
- /* reverse lookup */
- name_err = getnameinfo((struct sockaddr *) ss, ss_len,
- name_buf, name_buf_size,
- port_buf, port_buf_size,
- NI_NAMEREQD | NI_NUMERICSERV);
- if (name_err != 0) {
- strlcpy(name_buf, default_name, name_buf_size);
- rprintf(FLOG, "name lookup failed for %s: %s\n",
- client_addr(fd), gai_strerror(name_err));
- return name_err;
- }
-
- return 0;
-}
-
-
-
-/**
* Compare an addrinfo from the resolver to a sockinfo.
*
* Like strcmp, returns 0 for identical.
**/
-int compare_addrinfo_sockaddr(const struct addrinfo *ai,
- const struct sockaddr_storage *ss)
+static int compare_addrinfo_sockaddr(const struct addrinfo *ai, const struct sockaddr_storage *ss)
{
- int ss_family = get_sockaddr_family(ss);
+ int ss_family = GET_SOCKADDR_FAMILY(ss);
const char fn[] = "compare_addrinfo_sockaddr";
if (ai->ai_family != ss_family) {
@@ -258,8 +378,7 @@ int compare_addrinfo_sockaddr(const struct addrinfo *ai,
sin1 = (const struct sockaddr_in *) ss;
sin2 = (const struct sockaddr_in *) ai->ai_addr;
- return memcmp(&sin1->sin_addr, &sin2->sin_addr,
- sizeof sin1->sin_addr);
+ return memcmp(&sin1->sin_addr, &sin2->sin_addr, sizeof sin1->sin_addr);
}
#ifdef INET6
@@ -269,14 +388,13 @@ int compare_addrinfo_sockaddr(const struct addrinfo *ai,
sin1 = (const struct sockaddr_in6 *) ss;
sin2 = (const struct sockaddr_in6 *) ai->ai_addr;
- if (ai->ai_addrlen < sizeof (struct sockaddr_in6)) {
+ if (ai->ai_addrlen < (int)sizeof (struct sockaddr_in6)) {
rprintf(FLOG, "%s: too short sockaddr_in6; length=%d\n",
fn, (int)ai->ai_addrlen);
return 1;
}
- if (memcmp(&sin1->sin6_addr, &sin2->sin6_addr,
- sizeof sin1->sin6_addr))
+ if (memcmp(&sin1->sin6_addr, &sin2->sin6_addr, sizeof sin1->sin6_addr))
return 1;
#ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
@@ -302,13 +420,11 @@ int compare_addrinfo_sockaddr(const struct addrinfo *ai,
* because it doesn't seem that it could be spoofed in any way, and
* getaddrinfo on random service names seems to cause problems on AIX.
**/
-int check_name(int fd,
- const struct sockaddr_storage *ss,
- char *name_buf, size_t name_buf_size)
+static int check_name(const char *ipaddr, const struct sockaddr_storage *ss, char *name_buf, size_t name_buf_size)
{
struct addrinfo hints, *res, *res0;
int error;
- int ss_family = get_sockaddr_family(ss);
+ int ss_family = GET_SOCKADDR_FAMILY(ss);
memset(&hints, 0, sizeof hints);
hints.ai_family = ss_family;
@@ -339,10 +455,74 @@ int check_name(int fd,
/* We hit the end of the list without finding an
* address that was the same as ss. */
rprintf(FLOG, "%s is not a known address for \"%s\": "
- "spoofed address?\n", client_addr(fd), name_buf);
+ "spoofed address?\n", ipaddr, name_buf);
strlcpy(name_buf, default_name, name_buf_size);
}
freeaddrinfo(res0);
return 0;
}
+
+/* Returns 1 for a valid IPv4 or IPv6 addr, or 0 for a bad one. */
+static int valid_ipaddr(const char *s)
+{
+ int i;
+
+ if (strchr(s, ':') != NULL) { /* Only IPv6 has a colon. */
+ int count, saw_double_colon = 0;
+ int ipv4_at_end = 0;
+
+ if (*s == ':') { /* A colon at the start must be a :: */
+ if (*++s != ':')
+ return 0;
+ saw_double_colon = 1;
+ s++;
+ }
+
+ for (count = 0; count < 8; count++) {
+ if (!*s)
+ return saw_double_colon && count < 7;
+
+ if (strchr(s, ':') == NULL && strchr(s, '.') != NULL) {
+ if ((!saw_double_colon && count != 6) || (saw_double_colon && count > 6))
+ return 0;
+ ipv4_at_end = 1;
+ break;
+ }
+
+ if (!isHexDigit(s++)) /* Need 1-4 hex digits */
+ return 0;
+ if (isHexDigit(s) && isHexDigit(++s) && isHexDigit(++s) && isHexDigit(++s))
+ return 0;
+
+ if (*s == ':') {
+ if (!*++s)
+ return 0;
+ if (*s == ':') {
+ if (saw_double_colon)
+ return 0;
+ saw_double_colon = 1;
+ s++;
+ }
+ }
+ }
+
+ if (!ipv4_at_end)
+ return !*s;
+ }
+
+ /* IPv4 */
+ for (i = 0; i < 4; i++) {
+ long n;
+ char *end;
+
+ if (i && *s++ != '.')
+ return 0;
+ n = strtol(s, &end, 10);
+ if (n > 255 || n < 0 || end <= s || end > s+3)
+ return 0;
+ s = end;
+ }
+
+ return !*s;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-21 23:35:05 +0000