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lighttpd1.4/src/mod_proxy.c

1149 lines
43 KiB
C

#include "first.h"
#include <string.h>
#include <stdlib.h>
#include "gw_backend.h"
#include "base.h"
#include "array.h"
#include "buffer.h"
#include "fdevent.h"
#include "http_kv.h"
#include "http_header.h"
#include "log.h"
#include "sock_addr.h"
#include "status_counter.h"
/**
*
* HTTP reverse proxy
*
* TODO: - HTTP/1.1
* - HTTP/1.1 persistent connection with upstream servers
*/
/* (future: might split struct and move part to http-header-glue.c) */
typedef struct http_header_remap_opts {
const array *urlpaths;
const array *hosts_request;
const array *hosts_response;
int force_http10;
int https_remap;
int upgrade;
int connect_method;
/*(not used in plugin_config, but used in handler_ctx)*/
const buffer *http_host;
const buffer *forwarded_host;
const data_string *forwarded_urlpath;
} http_header_remap_opts;
typedef enum {
PROXY_FORWARDED_NONE = 0x00,
PROXY_FORWARDED_FOR = 0x01,
PROXY_FORWARDED_PROTO = 0x02,
PROXY_FORWARDED_HOST = 0x04,
PROXY_FORWARDED_BY = 0x08,
PROXY_FORWARDED_REMOTE_USER = 0x10
} proxy_forwarded_t;
typedef struct {
gw_plugin_config gw; /* start must match layout of gw_plugin_config */
unsigned int replace_http_host;
unsigned int forwarded;
http_header_remap_opts header;
} plugin_config;
typedef struct {
PLUGIN_DATA;
pid_t srv_pid; /* must match layout of gw_plugin_data through conf member */
plugin_config conf;
plugin_config defaults;
} plugin_data;
static int proxy_check_extforward;
typedef struct {
gw_handler_ctx gw;
http_response_opts opts;
plugin_config conf;
} handler_ctx;
INIT_FUNC(mod_proxy_init) {
return calloc(1, sizeof(plugin_data));
}
static void mod_proxy_free_config(plugin_data * const p)
{
if (NULL == p->cvlist) return;
/* (init i to 0 if global context; to 1 to skip empty global context) */
for (int i = !p->cvlist[0].v.u2[1], used = p->nconfig; i < used; ++i) {
config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
for (; -1 != cpv->k_id; ++cpv) {
switch (cpv->k_id) {
case 5: /* proxy.header */
if (cpv->vtype == T_CONFIG_LOCAL) free(cpv->v.v);
break;
default:
break;
}
}
}
}
FREE_FUNC(mod_proxy_free) {
plugin_data * const p = p_d;
mod_proxy_free_config(p);
gw_free(p);
}
static void mod_proxy_merge_config_cpv(plugin_config * const pconf, const config_plugin_value_t * const cpv)
{
switch (cpv->k_id) { /* index into static config_plugin_keys_t cpk[] */
case 0: /* proxy.server */
if (cpv->vtype == T_CONFIG_LOCAL) {
gw_plugin_config * const gw = cpv->v.v;
pconf->gw.exts = gw->exts;
pconf->gw.exts_auth = gw->exts_auth;
pconf->gw.exts_resp = gw->exts_resp;
}
break;
case 1: /* proxy.balance */
/*if (cpv->vtype == T_CONFIG_LOCAL)*//*always true here for this param*/
pconf->gw.balance = (int)cpv->v.u;
break;
case 2: /* proxy.debug */
pconf->gw.debug = (int)cpv->v.u;
break;
case 3: /* proxy.map-extensions */
pconf->gw.ext_mapping = cpv->v.a;
break;
case 4: /* proxy.forwarded */
/*if (cpv->vtype == T_CONFIG_LOCAL)*//*always true here for this param*/
pconf->forwarded = cpv->v.u;
break;
case 5: /* proxy.header */
/*if (cpv->vtype == T_CONFIG_LOCAL)*//*always true here for this param*/
pconf->header = *(http_header_remap_opts *)cpv->v.v; /*(copies struct)*/
break;
case 6: /* proxy.replace-http-host */
pconf->replace_http_host = cpv->v.u;
break;
default:/* should not happen */
return;
}
}
static void mod_proxy_merge_config(plugin_config * const pconf, const config_plugin_value_t *cpv)
{
do {
mod_proxy_merge_config_cpv(pconf, cpv);
} while ((++cpv)->k_id != -1);
}
static void mod_proxy_patch_config(request_st * const r, plugin_data * const p)
{
memcpy(&p->conf, &p->defaults, sizeof(plugin_config));
for (int i = 1, used = p->nconfig; i < used; ++i) {
if (config_check_cond(r, (uint32_t)p->cvlist[i].k_id))
mod_proxy_merge_config(&p->conf, p->cvlist+p->cvlist[i].v.u2[0]);
}
}
static unsigned int mod_proxy_parse_forwarded(server *srv, const array *a)
{
unsigned int forwarded = 0;
for (uint32_t j = 0, used = a->used; j < used; ++j) {
proxy_forwarded_t param;
data_unset *du = a->data[j];
if (buffer_eq_slen(&du->key, CONST_STR_LEN("by")))
param = PROXY_FORWARDED_BY;
else if (buffer_eq_slen(&du->key, CONST_STR_LEN("for")))
param = PROXY_FORWARDED_FOR;
else if (buffer_eq_slen(&du->key, CONST_STR_LEN("host")))
param = PROXY_FORWARDED_HOST;
else if (buffer_eq_slen(&du->key, CONST_STR_LEN("proto")))
param = PROXY_FORWARDED_PROTO;
else if (buffer_eq_slen(&du->key, CONST_STR_LEN("remote_user")))
param = PROXY_FORWARDED_REMOTE_USER;
else {
log_error(srv->errh, __FILE__, __LINE__,
"proxy.forwarded keys must be one of: "
"by, for, host, proto, remote_user, but not: %s", du->key.ptr);
return UINT_MAX;
}
int val = config_plugin_value_tobool(du, 2);
if (2 == val) {
log_error(srv->errh, __FILE__, __LINE__,
"proxy.forwarded values must be one of: "
"0, 1, enable, disable; error for key: %s", du->key.ptr);
return UINT_MAX;
}
if (val)
forwarded |= param;
}
return forwarded;
}
static http_header_remap_opts * mod_proxy_parse_header_opts(server *srv, const array *a)
{
http_header_remap_opts header;
memset(&header, 0, sizeof(header));
for (uint32_t j = 0, used = a->used; j < used; ++j) {
data_array *da = (data_array *)a->data[j];
if (buffer_eq_slen(&da->key, CONST_STR_LEN("https-remap"))) {
int val = config_plugin_value_tobool((data_unset *)da, 2);
if (2 == val) {
log_error(srv->errh, __FILE__, __LINE__,
"unexpected value for proxy.header; "
"expected \"https-remap\" => \"enable\" or \"disable\"");
return NULL;
}
header.https_remap = val;
continue;
}
else if (buffer_eq_slen(&da->key, CONST_STR_LEN("force-http10"))) {
int val = config_plugin_value_tobool((data_unset *)da, 2);
if (2 == val) {
log_error(srv->errh, __FILE__, __LINE__,
"unexpected value for proxy.header; "
"expected \"force-http10\" => \"enable\" or \"disable\"");
return NULL;
}
header.force_http10 = val;
continue;
}
else if (buffer_eq_slen(&da->key, CONST_STR_LEN("upgrade"))) {
int val = config_plugin_value_tobool((data_unset *)da, 2);
if (2 == val) {
log_error(srv->errh, __FILE__, __LINE__,
"unexpected value for proxy.header; "
"expected \"upgrade\" => \"enable\" or \"disable\"");
return NULL;
}
header.upgrade = val;
continue;
}
else if (buffer_eq_slen(&da->key, CONST_STR_LEN("connect"))) {
int val = config_plugin_value_tobool((data_unset *)da, 2);
if (2 == val) {
log_error(srv->errh, __FILE__, __LINE__,
"unexpected value for proxy.header; "
"expected \"connect\" => \"enable\" or \"disable\"");
return NULL;
}
header.connect_method = val;
continue;
}
if (da->type != TYPE_ARRAY || !array_is_kvstring(&da->value)) {
log_error(srv->errh, __FILE__, __LINE__,
"unexpected value for proxy.header; "
"expected ( \"param\" => ( \"key\" => \"value\" ) ) near key %s",
da->key.ptr);
return NULL;
}
if (buffer_eq_slen(&da->key, CONST_STR_LEN("map-urlpath"))) {
header.urlpaths = &da->value;
}
else if (buffer_eq_slen(&da->key, CONST_STR_LEN("map-host-request"))) {
header.hosts_request = &da->value;
}
else if (buffer_eq_slen(&da->key, CONST_STR_LEN("map-host-response"))) {
header.hosts_response = &da->value;
}
else {
log_error(srv->errh, __FILE__, __LINE__,
"unexpected key for proxy.header; "
"expected ( \"param\" => ( \"key\" => \"value\" ) ) near key %s",
da->key.ptr);
return NULL;
}
}
http_header_remap_opts *opts = malloc(sizeof(header));
force_assert(opts);
memcpy(opts, &header, sizeof(header));
return opts;
}
SETDEFAULTS_FUNC(mod_proxy_set_defaults)
{
static const config_plugin_keys_t cpk[] = {
{ CONST_STR_LEN("proxy.server"),
T_CONFIG_ARRAY_KVARRAY,
T_CONFIG_SCOPE_CONNECTION }
,{ CONST_STR_LEN("proxy.balance"),
T_CONFIG_STRING,
T_CONFIG_SCOPE_CONNECTION }
,{ CONST_STR_LEN("proxy.debug"),
T_CONFIG_INT,
T_CONFIG_SCOPE_CONNECTION }
,{ CONST_STR_LEN("proxy.map-extensions"),
T_CONFIG_ARRAY_KVSTRING,
T_CONFIG_SCOPE_CONNECTION }
,{ CONST_STR_LEN("proxy.forwarded"),
T_CONFIG_ARRAY_KVANY,
T_CONFIG_SCOPE_CONNECTION }
,{ CONST_STR_LEN("proxy.header"),
T_CONFIG_ARRAY_KVANY,
T_CONFIG_SCOPE_CONNECTION }
,{ CONST_STR_LEN("proxy.replace-http-host"),
T_CONFIG_BOOL,
T_CONFIG_SCOPE_CONNECTION }
,{ NULL, 0,
T_CONFIG_UNSET,
T_CONFIG_SCOPE_UNSET }
};
plugin_data * const p = p_d;
if (!config_plugin_values_init(srv, p, cpk, "mod_proxy"))
return HANDLER_ERROR;
/* process and validate config directives
* (init i to 0 if global context; to 1 to skip empty global context) */
for (int i = !p->cvlist[0].v.u2[1]; i < p->nconfig; ++i) {
config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
gw_plugin_config *gw = NULL;
for (; -1 != cpv->k_id; ++cpv) {
switch (cpv->k_id) {
case 0: /* proxy.server */
gw = calloc(1, sizeof(gw_plugin_config));
force_assert(gw);
if (!gw_set_defaults_backend(srv, (gw_plugin_data *)p, cpv->v.a,
gw, 0, cpk[cpv->k_id].k)) {
gw_plugin_config_free(gw);
return HANDLER_ERROR;
}
/* error if "mode" = "authorizer";
* proxy can not act as authorizer */
/*(check after gw_set_defaults_backend())*/
if (gw->exts_auth && gw->exts_auth->used) {
log_error(srv->errh, __FILE__, __LINE__,
"%s must not define any hosts with "
"attribute \"mode\" = \"authorizer\"", cpk[cpv->k_id].k);
gw_plugin_config_free(gw);
return HANDLER_ERROR;
}
cpv->v.v = gw;
cpv->vtype = T_CONFIG_LOCAL;
break;
case 1: /* proxy.balance */
cpv->v.u = (unsigned int)gw_get_defaults_balance(srv, cpv->v.b);
break;
case 2: /* proxy.debug */
case 3: /* proxy.map-extensions */
break;
case 4: /* proxy.forwarded */
cpv->v.u = mod_proxy_parse_forwarded(srv, cpv->v.a);
if (UINT_MAX == cpv->v.u) return HANDLER_ERROR;
cpv->vtype = T_CONFIG_LOCAL;
break;
case 5: /* proxy.header */
cpv->v.v = mod_proxy_parse_header_opts(srv, cpv->v.a);
if (NULL == cpv->v.v) return HANDLER_ERROR;
cpv->vtype = T_CONFIG_LOCAL;
break;
case 6: /* proxy.replace-http-host */
break;
default:/* should not happen */
break;
}
}
/* disable check-local for all exts (default enabled) */
if (gw && gw->exts) { /*(check after gw_set_defaults_backend())*/
gw_exts_clear_check_local(gw->exts);
}
}
/* default is 0 */
/*p->defaults.balance = (unsigned int)gw_get_defaults_balance(srv, NULL);*/
p->defaults.header.force_http10 =
srv->srvconf.feature_flags
&& config_plugin_value_tobool(
array_get_element_klen(srv->srvconf.feature_flags,
CONST_STR_LEN("proxy.force-http10")), 0);
/* initialize p->defaults from global config context */
if (p->nconfig > 0 && p->cvlist->v.u2[1]) {
const config_plugin_value_t *cpv = p->cvlist + p->cvlist->v.u2[0];
if (-1 != cpv->k_id)
mod_proxy_merge_config(&p->defaults, cpv);
}
/* special-case behavior if mod_extforward is loaded */
for (uint32_t i = 0; i < srv->srvconf.modules->used; ++i) {
buffer *m = &((data_string *)srv->srvconf.modules->data[i])->value;
if (buffer_eq_slen(m, CONST_STR_LEN("mod_extforward"))) {
proxy_check_extforward = 1;
break;
}
}
return HANDLER_GO_ON;
}
/* (future: might move to http-header-glue.c) */
static const buffer * http_header_remap_host_match (buffer *b, size_t off, http_header_remap_opts *remap_hdrs, int is_req, size_t alen)
{
const array *hosts = is_req
? remap_hdrs->hosts_request
: remap_hdrs->hosts_response;
if (hosts) {
const char * const s = b->ptr+off;
for (size_t i = 0, used = hosts->used; i < used; ++i) {
const data_string * const ds = (data_string *)hosts->data[i];
const buffer *k = &ds->key;
size_t mlen = buffer_clen(k);
if (1 == mlen && k->ptr[0] == '-') {
/* match with authority provided in Host (if is_req)
* (If no Host in client request, then matching against empty
* string will probably not match, and no remap will be
* performed) */
k = is_req
? remap_hdrs->http_host
: remap_hdrs->forwarded_host;
if (NULL == k) continue;
mlen = buffer_clen(k);
}
if (buffer_eq_icase_ss(s, alen, k->ptr, mlen)) {
if (buffer_is_equal_string(&ds->value, CONST_STR_LEN("-"))) {
return remap_hdrs->http_host;
}
else if (!buffer_is_blank(&ds->value)) {
/*(save first matched request host for response match)*/
if (is_req && NULL == remap_hdrs->forwarded_host)
remap_hdrs->forwarded_host = &ds->value;
return &ds->value;
} /*(else leave authority as-is and stop matching)*/
break;
}
}
}
return NULL;
}
/* (future: might move to http-header-glue.c) */
static size_t http_header_remap_host (buffer *b, size_t off, http_header_remap_opts *remap_hdrs, int is_req, size_t alen)
{
const buffer * const m =
http_header_remap_host_match(b, off, remap_hdrs, is_req, alen);
if (NULL == m) return alen; /*(no match; return original authority length)*/
buffer_substr_replace(b, off, alen, m);
return buffer_clen(m); /*(length of replacement authority)*/
}
/* (future: might move to http-header-glue.c) */
static size_t http_header_remap_urlpath (buffer *b, size_t off, http_header_remap_opts *remap_hdrs, int is_req)
{
const array *urlpaths = remap_hdrs->urlpaths;
if (urlpaths) {
const char * const s = b->ptr+off;
const size_t plen = buffer_clen(b) - off; /*(urlpath len)*/
if (is_req) { /* request */
for (size_t i = 0, used = urlpaths->used; i < used; ++i) {
const data_string * const ds = (data_string *)urlpaths->data[i];
const size_t mlen = buffer_clen(&ds->key);
if (mlen <= plen && 0 == memcmp(s, ds->key.ptr, mlen)) {
if (NULL == remap_hdrs->forwarded_urlpath)
remap_hdrs->forwarded_urlpath = ds;
buffer_substr_replace(b, off, mlen, &ds->value);
return buffer_clen(&ds->value);/*(replacement len)*/
}
}
}
else { /* response; perform reverse map */
if (NULL != remap_hdrs->forwarded_urlpath) {
const data_string * const ds = remap_hdrs->forwarded_urlpath;
const size_t mlen = buffer_clen(&ds->value);
if (mlen <= plen && 0 == memcmp(s, ds->value.ptr, mlen)) {
buffer_substr_replace(b, off, mlen, &ds->key);
return buffer_clen(&ds->key); /*(replacement len)*/
}
}
for (size_t i = 0, used = urlpaths->used; i < used; ++i) {
const data_string * const ds = (data_string *)urlpaths->data[i];
const size_t mlen = buffer_clen(&ds->value);
if (mlen <= plen && 0 == memcmp(s, ds->value.ptr, mlen)) {
buffer_substr_replace(b, off, mlen, &ds->key);
return buffer_clen(&ds->key); /*(replacement len)*/
}
}
}
}
return 0;
}
/* (future: might move to http-header-glue.c) */
static void http_header_remap_uri (buffer *b, size_t off, http_header_remap_opts *remap_hdrs, int is_req)
{
/* find beginning of URL-path (might be preceded by scheme://authority
* (caller should make sure any leading whitespace is prior to offset) */
if (b->ptr[off] != '/') {
char *s = b->ptr+off;
size_t alen; /*(authority len (host len))*/
size_t slen; /*(scheme len)*/
const buffer *m;
/* skip over scheme and authority of URI to find beginning of URL-path
* (value might conceivably be relative URL-path instead of URI) */
if (NULL == (s = strchr(s, ':')) || s[1] != '/' || s[2] != '/') return;
slen = s - (b->ptr+off);
s += 3;
off = (size_t)(s - b->ptr);
if (NULL != (s = strchr(s, '/'))) {
alen = (size_t)(s - b->ptr) - off;
if (0 == alen) return; /*(empty authority, e.g. "http:///")*/
}
else {
alen = buffer_clen(b) - off;
if (0 == alen) return; /*(empty authority, e.g. "http:///")*/
buffer_append_string_len(b, CONST_STR_LEN("/"));
}
/* remap authority (if configured) and set offset to url-path */
m = http_header_remap_host_match(b, off, remap_hdrs, is_req, alen);
if (NULL != m) {
if (remap_hdrs->https_remap
&& (is_req ? 5==slen && 0==memcmp(b->ptr+off-slen-3,"https",5)
: 4==slen && 0==memcmp(b->ptr+off-slen-3,"http",4))){
if (is_req) {
memcpy(b->ptr+off-slen-3+4,"://",3); /*("https"=>"http")*/
--off;
++alen;
}
else {/*(!is_req)*/
memcpy(b->ptr+off-slen-3+4,"s://",4); /*("http" =>"https")*/
++off;
--alen;
}
}
buffer_substr_replace(b, off, alen, m);
alen = buffer_clen(m);/*(length of replacement authority)*/
}
off += alen;
}
/* remap URLs (if configured) */
http_header_remap_urlpath(b, off, remap_hdrs, is_req);
}
/* (future: might move to http-header-glue.c) */
static void http_header_remap_setcookie (buffer *b, size_t off, http_header_remap_opts *remap_hdrs)
{
/* Given the special-case of Set-Cookie and the (too) loosely restricted
* characters allowed, for best results, the Set-Cookie value should be the
* entire string in b from offset to end of string. In response headers,
* lighttpd may concatenate multiple Set-Cookie headers into single entry
* in r->resp_headers, separated by "\r\nSet-Cookie: " */
for (char *s = b->ptr+off, *e; *s; s = e) {
size_t len;
{
while (*s != ';' && *s != '\n' && *s != '\0') ++s;
if (*s == '\n') {
/*(include +1 for '\n', but leave ' ' for ++s below)*/
s += sizeof("Set-Cookie:");
}
if ('\0' == *s) return;
do { ++s; } while (*s == ' ' || *s == '\t');
if ('\0' == *s) return;
e = s+1;
if ('=' == *s) continue;
/*(interested only in Domain and Path attributes)*/
while (*e != '=' && *e != '\0') ++e;
if ('\0' == *e) return;
++e;
switch ((int)(e - s - 1)) {
case 4:
if (buffer_eq_icase_ssn(s, "path", 4)) {
if (*e == '"') ++e;
if (*e != '/') continue;
off = (size_t)(e - b->ptr);
len = http_header_remap_urlpath(b, off, remap_hdrs, 0);
e = b->ptr+off+len; /*(b may have been reallocated)*/
continue;
}
break;
case 6:
if (buffer_eq_icase_ssn(s, "domain", 6)) {
size_t alen = 0;
if (*e == '"') ++e;
if (*e == '.') ++e;
if (*e == ';') continue;
off = (size_t)(e - b->ptr);
for (char c; (c = e[alen]) != ';' && c != ' ' && c != '\t'
&& c != '\r' && c != '\0'; ++alen);
len = http_header_remap_host(b, off, remap_hdrs, 0, alen);
e = b->ptr+off+len; /*(b may have been reallocated)*/
continue;
}
break;
default:
break;
}
}
}
}
static void buffer_append_string_backslash_escaped(buffer *b, const char *s, size_t len) {
/* (future: might move to buffer.c) */
size_t j = 0;
char * const p = buffer_string_prepare_append(b, len*2 + 4);
for (size_t i = 0; i < len; ++i) {
int c = s[i];
if (c == '"' || c == '\\' || c == 0x7F || (c < 0x20 && c != '\t'))
p[j++] = '\\';
p[j++] = c;
}
buffer_commit(b, j);
}
static void proxy_set_Forwarded(connection * const con, request_st * const r, const unsigned int flags) {
buffer *b = NULL, *efor = NULL, *eproto = NULL, *ehost = NULL;
int semicolon = 0;
if (proxy_check_extforward) {
efor =
http_header_env_get(r, CONST_STR_LEN("_L_EXTFORWARD_ACTUAL_FOR"));
eproto =
http_header_env_get(r, CONST_STR_LEN("_L_EXTFORWARD_ACTUAL_PROTO"));
ehost =
http_header_env_get(r, CONST_STR_LEN("_L_EXTFORWARD_ACTUAL_HOST"));
}
/* note: set "Forwarded" prior to updating X-Forwarded-For (below) */
if (flags)
b = http_header_request_get(r, HTTP_HEADER_FORWARDED, CONST_STR_LEN("Forwarded"));
if (flags && NULL == b) {
const buffer *xff =
http_header_request_get(r, HTTP_HEADER_X_FORWARDED_FOR, CONST_STR_LEN("X-Forwarded-For"));
b = http_header_request_set_ptr(r, HTTP_HEADER_FORWARDED,
CONST_STR_LEN("Forwarded"));
if (NULL != xff) {
/* use X-Forwarded-For contents to seed Forwarded */
char *s = xff->ptr;
size_t used = buffer_clen(xff);
for (size_t i=0, j, ipv6; i < used; ++i) {
while (s[i] == ' ' || s[i] == '\t' || s[i] == ',') ++i;
if (s[i] == '\0') break;
j = i;
do {
++i;
} while (s[i]!=' ' && s[i]!='\t' && s[i]!=',' && s[i]!='\0');
/* over-simplified test expecting only IPv4 or IPv6 addresses,
* (not expecting :port, so treat existence of colon as IPv6,
* and not expecting unix paths, especially not containing ':')
* quote all strings, backslash-escape since IPs not validated*/
ipv6 = (NULL != memchr(s+j, ':', i-j)); /*(over-simplified) */
ipv6
? buffer_append_string_len(b, CONST_STR_LEN("for=\"["))
: buffer_append_string_len(b, CONST_STR_LEN("for=\""));
buffer_append_string_backslash_escaped(b, s+j, i-j);
ipv6
? buffer_append_string_len(b, CONST_STR_LEN("]\", "))
: buffer_append_string_len(b, CONST_STR_LEN("\", "));
}
}
} else if (flags) { /*(NULL != b)*/
buffer_append_string_len(b, CONST_STR_LEN(", "));
}
if (flags & PROXY_FORWARDED_FOR) {
int family = sock_addr_get_family(&con->dst_addr);
buffer_append_string_len(b, CONST_STR_LEN("for="));
if (NULL != efor) {
/* over-simplified test expecting only IPv4 or IPv6 addresses,
* (not expecting :port, so treat existence of colon as IPv6,
* and not expecting unix paths, especially not containing ':')
* quote all strings and backslash-escape since IPs not validated
* (should be IP from original con->dst_addr_buf,
* so trustable and without :port) */
int ipv6 = (NULL != strchr(efor->ptr, ':'));
ipv6
? buffer_append_string_len(b, CONST_STR_LEN("\"["))
: buffer_append_string_len(b, CONST_STR_LEN("\""));
buffer_append_string_backslash_escaped(b, BUF_PTR_LEN(efor));
ipv6
? buffer_append_string_len(b, CONST_STR_LEN("]\""))
: buffer_append_string_len(b, CONST_STR_LEN("\""));
} else if (family == AF_INET) {
/*(Note: if :port is added, then must be quoted-string:
* e.g. for="...:port")*/
buffer_append_string_buffer(b, &con->dst_addr_buf);
} else if (family == AF_INET6) {
buffer_append_str3(b, CONST_STR_LEN("\"["),
BUF_PTR_LEN(&con->dst_addr_buf),
CONST_STR_LEN("]\""));
} else {
buffer_append_string_len(b, CONST_STR_LEN("\""));
buffer_append_string_backslash_escaped(
b, BUF_PTR_LEN(&con->dst_addr_buf));
buffer_append_string_len(b, CONST_STR_LEN("\""));
}
semicolon = 1;
}
if (flags & PROXY_FORWARDED_BY) {
int family = sock_addr_get_family(&con->srv_socket->addr);
/* Note: getsockname() and inet_ntop() are expensive operations.
* (recommendation: do not to enable by=... unless required)
* future: might use con->srv_socket->srv_token if addr is not
* INADDR_ANY or in6addr_any, but must omit optional :port
* from con->srv_socket->srv_token for consistency */
if (semicolon) buffer_append_string_len(b, CONST_STR_LEN(";"));
buffer_append_string_len(b, CONST_STR_LEN("by=\""));
#ifdef HAVE_SYS_UN_H
/* special-case: might need to encode unix domain socket path */
if (family == AF_UNIX) {
buffer_append_string_backslash_escaped(
b, BUF_PTR_LEN(con->srv_socket->srv_token));
}
else
#endif
{
sock_addr addr;
socklen_t addrlen = sizeof(addr);
if (0 == getsockname(con->fd,(struct sockaddr *)&addr, &addrlen)) {
sock_addr_stringify_append_buffer(b, &addr);
}
}
buffer_append_string_len(b, CONST_STR_LEN("\""));
semicolon = 1;
}
if (flags & PROXY_FORWARDED_PROTO) {
/* expecting "http" or "https"
* (not checking if quoted-string and encoding needed) */
if (semicolon) buffer_append_string_len(b, CONST_STR_LEN(";"));
if (NULL != eproto) {
buffer_append_str2(b, CONST_STR_LEN("proto="), BUF_PTR_LEN(eproto));
} else if (con->srv_socket->is_ssl) {
buffer_append_string_len(b, CONST_STR_LEN("proto=https"));
} else {
buffer_append_string_len(b, CONST_STR_LEN("proto=http"));
}
semicolon = 1;
}
if (flags & PROXY_FORWARDED_HOST) {
if (NULL != ehost) {
if (semicolon)
buffer_append_string_len(b, CONST_STR_LEN(";"));
buffer_append_string_len(b, CONST_STR_LEN("host=\""));
buffer_append_string_backslash_escaped(
b, BUF_PTR_LEN(ehost));
buffer_append_string_len(b, CONST_STR_LEN("\""));
semicolon = 1;
} else if (r->http_host && !buffer_is_blank(r->http_host)) {
if (semicolon)
buffer_append_string_len(b, CONST_STR_LEN(";"));
buffer_append_string_len(b, CONST_STR_LEN("host=\""));
buffer_append_string_backslash_escaped(
b, BUF_PTR_LEN(r->http_host));
buffer_append_string_len(b, CONST_STR_LEN("\""));
semicolon = 1;
}
}
if (flags & PROXY_FORWARDED_REMOTE_USER) {
const buffer *remote_user =
http_header_env_get(r, CONST_STR_LEN("REMOTE_USER"));
if (NULL != remote_user) {
if (semicolon)
buffer_append_string_len(b, CONST_STR_LEN(";"));
buffer_append_string_len(b, CONST_STR_LEN("remote_user=\""));
buffer_append_string_backslash_escaped(
b, BUF_PTR_LEN(remote_user));
buffer_append_string_len(b, CONST_STR_LEN("\""));
/*semicolon = 1;*/
}
}
/* legacy X-* headers, including X-Forwarded-For */
b = (NULL != efor) ? efor : &con->dst_addr_buf;
http_header_request_set(r, HTTP_HEADER_X_FORWARDED_FOR,
CONST_STR_LEN("X-Forwarded-For"),
BUF_PTR_LEN(b));
b = (NULL != ehost) ? ehost : r->http_host;
if (b && !buffer_is_blank(b)) {
http_header_request_set(r, HTTP_HEADER_OTHER,
CONST_STR_LEN("X-Host"),
BUF_PTR_LEN(b));
http_header_request_set(r, HTTP_HEADER_OTHER,
CONST_STR_LEN("X-Forwarded-Host"),
BUF_PTR_LEN(b));
}
b = (NULL != eproto) ? eproto : &r->uri.scheme;
http_header_request_set(r, HTTP_HEADER_X_FORWARDED_PROTO,
CONST_STR_LEN("X-Forwarded-Proto"),
BUF_PTR_LEN(b));
}
static handler_t proxy_stdin_append(gw_handler_ctx *hctx) {
/*handler_ctx *hctx = (handler_ctx *)gwhctx;*/
chunkqueue * const req_cq = &hctx->r->reqbody_queue;
const off_t req_cqlen = chunkqueue_length(req_cq);
if (req_cqlen) {
/* XXX: future: use http_chunk_len_append() */
buffer * const tb = hctx->r->tmp_buf;
buffer_clear(tb);
buffer_append_uint_hex_lc(tb, (uintmax_t)req_cqlen);
buffer_append_string_len(tb, CONST_STR_LEN("\r\n"));
const off_t len = (off_t)buffer_clen(tb)
+ 2 /*(+2 end chunk "\r\n")*/
+ req_cqlen;
if (-1 != hctx->wb_reqlen)
hctx->wb_reqlen += (hctx->wb_reqlen >= 0) ? len : -len;
(chunkqueue_is_empty(&hctx->wb) || hctx->wb.first->type == MEM_CHUNK)
/* else FILE_CHUNK for temp file */
? chunkqueue_append_mem(&hctx->wb, BUF_PTR_LEN(tb))
: chunkqueue_append_mem_min(&hctx->wb, BUF_PTR_LEN(tb));
chunkqueue_steal(&hctx->wb, req_cq, req_cqlen);
chunkqueue_append_mem_min(&hctx->wb, CONST_STR_LEN("\r\n"));
}
if (hctx->wb.bytes_in == hctx->wb_reqlen) {/*hctx->r->reqbody_length >= 0*/
/* terminate STDIN */
chunkqueue_append_mem(&hctx->wb, CONST_STR_LEN("0\r\n\r\n"));
hctx->wb_reqlen += (int)sizeof("0\r\n\r\n");
}
return HANDLER_GO_ON;
}
static handler_t proxy_create_env(gw_handler_ctx *gwhctx) {
handler_ctx *hctx = (handler_ctx *)gwhctx;
request_st * const r = hctx->gw.r;
const int remap_headers = (NULL != hctx->conf.header.urlpaths
|| NULL != hctx->conf.header.hosts_request);
size_t rsz = (size_t)(r->read_queue.bytes_out - hctx->gw.wb.bytes_in);
if (rsz >= 65536) rsz = r->rqst_header_len;
buffer * const b = chunkqueue_prepend_buffer_open_sz(&hctx->gw.wb, rsz);
/* build header */
/* request line */
const buffer * const m = http_method_buf(r->http_method);
buffer_append_str3(b,
BUF_PTR_LEN(m),
CONST_STR_LEN(" "),
BUF_PTR_LEN(&r->target));
if (remap_headers)
http_header_remap_uri(b, buffer_clen(b) - buffer_clen(&r->target),
&hctx->conf.header, 1);
buffer_append_string_len(b, !hctx->conf.header.force_http10
? " HTTP/1.1" : " HTTP/1.0",
sizeof(" HTTP/1.1")-1);
if (hctx->conf.replace_http_host && !buffer_is_blank(hctx->gw.host->id)) {
if (hctx->gw.conf.debug > 1) {
log_error(r->conf.errh, __FILE__, __LINE__,
"proxy - using \"%s\" as HTTP Host", hctx->gw.host->id->ptr);
}
buffer_append_str2(b, CONST_STR_LEN("\r\nHost: "),
BUF_PTR_LEN(hctx->gw.host->id));
} else if (r->http_host && !buffer_is_unset(r->http_host)) {
buffer_append_str2(b, CONST_STR_LEN("\r\nHost: "),
BUF_PTR_LEN(r->http_host));
if (remap_headers) {
size_t alen = buffer_clen(r->http_host);
http_header_remap_host(b, buffer_clen(b) - alen, &hctx->conf.header, 1, alen);
}
} else {
/* no Host header available; must send HTTP/1.0 request */
b->ptr[b->used-2] = '0'; /*(overwrite end of request line)*/
}
if (r->reqbody_length > 0
|| (0 == r->reqbody_length
&& !http_method_get_or_head(r->http_method))) {
/* set Content-Length if client sent Transfer-Encoding: chunked
* and not streaming to backend (request body has been fully received) */
const buffer *vb = http_header_request_get(r, HTTP_HEADER_CONTENT_LENGTH, CONST_STR_LEN("Content-Length"));
if (NULL == vb) {
buffer_append_int(
http_header_request_set_ptr(r, HTTP_HEADER_CONTENT_LENGTH,
CONST_STR_LEN("Content-Length")),
r->reqbody_length);
}
}
else if (!hctx->conf.header.force_http10
&& -1 == r->reqbody_length
&& (r->conf.stream_request_body
& (FDEVENT_STREAM_REQUEST | FDEVENT_STREAM_REQUEST_BUFMIN))) {
hctx->gw.stdin_append = proxy_stdin_append; /* stream chunked body */
buffer_append_string_len(b, CONST_STR_LEN("\r\nTransfer-Encoding: chunked"));
}
/* "Forwarded" and legacy X- headers */
proxy_set_Forwarded(r->con, r, hctx->conf.forwarded);
/* request header */
const buffer *connhdr = NULL;
const buffer *te = NULL;
const buffer *upgrade = NULL;
for (size_t i = 0, used = r->rqst_headers.used; i < used; ++i) {
const data_string * const ds = (data_string *)r->rqst_headers.data[i];
switch (ds->ext) {
default:
break;
case HTTP_HEADER_HOST:
continue; /*(handled further above)*/
case HTTP_HEADER_OTHER:
if (__builtin_expect( ('p' == (ds->key.ptr[0] | 0x20)), 0)) {
if (buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("Proxy-Connection"))) continue;
/* Do not emit HTTP_PROXY in environment.
* Some executables use HTTP_PROXY to configure
* outgoing proxy. See also https://httpoxy.org/ */
if (buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("Proxy"))) continue;
}
break;
case HTTP_HEADER_TE:
if (hctx->conf.header.force_http10 || r->http_version == HTTP_VERSION_1_0) continue;
/* ignore if not exactly "trailers" */
if (!buffer_eq_icase_slen(&ds->value, CONST_STR_LEN("trailers"))) continue;
/*if (!buffer_is_blank(&ds->value)) te = &ds->value;*/
te = &ds->value; /*("trailers")*/
break;
case HTTP_HEADER_UPGRADE:
if (hctx->conf.header.force_http10 || r->http_version == HTTP_VERSION_1_0) continue;
if (!hctx->conf.header.upgrade) continue;
if (!buffer_is_blank(&ds->value)) upgrade = &ds->value;
break;
case HTTP_HEADER_CONNECTION:
connhdr = &ds->value;
continue;
case HTTP_HEADER_SET_COOKIE:
continue; /*(response header only; avoid accidental reflection)*/
}
const uint32_t klen = buffer_clen(&ds->key);
const uint32_t vlen = buffer_clen(&ds->value);
if (0 == klen || 0 == vlen) continue;
char * restrict s = buffer_extend(b, klen+vlen+4);
s[0] = '\r';
s[1] = '\n';
memcpy(s+2, ds->key.ptr, klen);
s += 2+klen;
s[0] = ':';
s[1] = ' ';
memcpy(s+2, ds->value.ptr, vlen);
if (!remap_headers) continue;
/* check for hdrs for which to remap URIs in-place after append to b */
switch (klen) {
default:
continue;
#if 0 /* "URI" is HTTP response header (non-standard; historical in Apache) */
case 3:
if (ds->ext == HTTP_HEADER_OTHER && buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("URI"))) break;
continue;
#endif
#if 0 /* "Location" is HTTP response header */
case 8:
if (ds->ext == HTTP_HEADER_LOCATION) break;
continue;
#endif
case 11: /* "Destination" is WebDAV request header */
if (ds->ext == HTTP_HEADER_OTHER && buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("Destination"))) break;
continue;
case 16: /* "Content-Location" may be HTTP request or response header */
if (ds->ext == HTTP_HEADER_CONTENT_LOCATION) break;
continue;
}
http_header_remap_uri(b, buffer_clen(b) - vlen, &hctx->conf.header, 1);
}
if (connhdr && !hctx->conf.header.force_http10 && r->http_version >= HTTP_VERSION_1_1
&& !buffer_eq_icase_slen(connhdr, CONST_STR_LEN("close"))) {
/* mod_proxy always sends Connection: close to backend */
buffer_append_string_len(b, CONST_STR_LEN("\r\nConnection: close"));
/* (future: might be pedantic and also check Connection header for each
* token using http_header_str_contains_token() */
if (te)
buffer_append_string_len(b, CONST_STR_LEN(", te"));
if (upgrade)
buffer_append_string_len(b, CONST_STR_LEN(", upgrade"));
buffer_append_string_len(b, CONST_STR_LEN("\r\n\r\n"));
}
else /* mod_proxy always sends Connection: close to backend */
buffer_append_string_len(b, CONST_STR_LEN("\r\nConnection: close\r\n\r\n"));
hctx->gw.wb_reqlen = buffer_clen(b);
chunkqueue_prepend_buffer_commit(&hctx->gw.wb);
if (r->reqbody_length) {
if (r->reqbody_length > 0)
hctx->gw.wb_reqlen += r->reqbody_length; /* total req size */
else /* as-yet-unknown total request size (Transfer-Encoding: chunked)*/
hctx->gw.wb_reqlen = -hctx->gw.wb_reqlen;
if (hctx->gw.stdin_append == proxy_stdin_append)
proxy_stdin_append(&hctx->gw);
else
chunkqueue_append_chunkqueue(&hctx->gw.wb, &r->reqbody_queue);
}
status_counter_inc(CONST_STR_LEN("proxy.requests"));
return HANDLER_GO_ON;
}
static handler_t proxy_create_env_connect(gw_handler_ctx *gwhctx) {
handler_ctx *hctx = (handler_ctx *)gwhctx;
request_st * const r = hctx->gw.r;
r->http_status = 200; /* OK */
r->resp_body_started = 1;
gw_set_transparent(&hctx->gw);
http_response_upgrade_read_body_unknown(r);
status_counter_inc(CONST_STR_LEN("proxy.requests"));
return HANDLER_GO_ON;
}
static handler_t proxy_response_headers(request_st * const r, struct http_response_opts_t *opts) {
/* response headers just completed */
handler_ctx *hctx = (handler_ctx *)opts->pdata;
http_header_remap_opts * const remap_hdrs = &hctx->conf.header;
if (light_btst(r->resp_htags, HTTP_HEADER_UPGRADE)) {
if (remap_hdrs->upgrade && r->http_status == 101) {
/* 101 Switching Protocols; transition to transparent proxy */
gw_set_transparent(&hctx->gw);
http_response_upgrade_read_body_unknown(r);
}
else {
light_bclr(r->resp_htags, HTTP_HEADER_UPGRADE);
#if 0
/* preserve prior questionable behavior; likely broken behavior
* anyway if backend thinks connection is being upgraded but client
* does not receive Connection: upgrade */
http_header_response_unset(r, HTTP_HEADER_UPGRADE,
CONST_STR_LEN("Upgrade"))
#endif
}
}
/* rewrite paths, if needed */
if (NULL == remap_hdrs->urlpaths && NULL == remap_hdrs->hosts_response)
return HANDLER_GO_ON;
buffer *vb;
if (light_btst(r->resp_htags, HTTP_HEADER_LOCATION)) {
vb = http_header_response_get(r, HTTP_HEADER_LOCATION,
CONST_STR_LEN("Location"));
if (vb) http_header_remap_uri(vb, 0, remap_hdrs, 0);
}
if (light_btst(r->resp_htags, HTTP_HEADER_CONTENT_LOCATION)) {
vb = http_header_response_get(r, HTTP_HEADER_CONTENT_LOCATION,
CONST_STR_LEN("Content-Location"));
if (vb) http_header_remap_uri(vb, 0, remap_hdrs, 0);
}
if (light_btst(r->resp_htags, HTTP_HEADER_SET_COOKIE)) {
vb = http_header_response_get(r, HTTP_HEADER_SET_COOKIE,
CONST_STR_LEN("Set-Cookie"));
if (vb) http_header_remap_setcookie(vb, 0, remap_hdrs);
}
return HANDLER_GO_ON;
}
static handler_t mod_proxy_check_extension(request_st * const r, void *p_d) {
plugin_data *p = p_d;
handler_t rc;
if (NULL != r->handler_module) return HANDLER_GO_ON;
mod_proxy_patch_config(r, p);
if (NULL == p->conf.gw.exts) return HANDLER_GO_ON;
rc = gw_check_extension(r, (gw_plugin_data *)p, 1, sizeof(handler_ctx));
if (HANDLER_GO_ON != rc) return rc;
if (r->handler_module == p->self) {
handler_ctx *hctx = r->plugin_ctx[p->id];
hctx->gw.create_env = proxy_create_env;
hctx->gw.response = chunk_buffer_acquire();
hctx->gw.opts.backend = BACKEND_PROXY;
hctx->gw.opts.pdata = hctx;
hctx->gw.opts.headers = proxy_response_headers;
hctx->conf = p->conf; /*(copies struct)*/
hctx->conf.header.http_host = r->http_host;
hctx->conf.header.upgrade &= (r->http_version == HTTP_VERSION_1_1);
/* mod_proxy currently sends all backend requests as http.
* https-remap is a flag since it might not be needed if backend
* honors Forwarded or X-Forwarded-Proto headers, e.g. by using
* lighttpd mod_extforward or similar functionality in backend*/
if (hctx->conf.header.https_remap) {
hctx->conf.header.https_remap =
buffer_is_equal_string(&r->uri.scheme, CONST_STR_LEN("https"));
}
if (r->http_method == HTTP_METHOD_CONNECT) {
/*(note: not requiring HTTP/1.1 due to too many non-compliant
* clients such as 'openssl s_client')*/
if (hctx->conf.header.connect_method) {
hctx->gw.create_env = proxy_create_env_connect;
}
else {
r->http_status = 405; /* Method Not Allowed */
r->handler_module = NULL;
return HANDLER_FINISHED;
}
}
}
return HANDLER_GO_ON;
}
int mod_proxy_plugin_init(plugin *p);
int mod_proxy_plugin_init(plugin *p) {
p->version = LIGHTTPD_VERSION_ID;
p->name = "proxy";
p->init = mod_proxy_init;
p->cleanup = mod_proxy_free;
p->set_defaults = mod_proxy_set_defaults;
p->handle_request_reset = gw_handle_request_reset;
p->handle_uri_clean = mod_proxy_check_extension;
p->handle_subrequest = gw_handle_subrequest;
p->handle_trigger = gw_handle_trigger;
p->handle_waitpid = gw_handle_waitpid_cb;
return 0;
}