Perl: propagate errors.
When an error happens, the ctx->error bit is now set, and croak()
is called to terminate further processing. The ctx->error bit is
checked in ngx_http_perl_call_handler() to cancel further processing,
and is also checked in various output functions - to make sure these won't
be called if croak() was handled by an eval{} in perl code.
In particular, this ensures that output chain won't be called after
errors, as filters might not expect this to happen. This fixes some
segmentation faults under low memory conditions. Also this stops
request processing after filter finalization or request body reading
errors.
For cases where an HTTP error status can be additionally returned (for
example, 416 (Requested Range Not Satisfiable) from the range filter),
the ctx->status field is also added.
diff --git a/src/http/modules/perl/nginx.xs b/src/http/modules/perl/nginx.xs
index 2e9808f..8e17f6d 100644
--- a/src/http/modules/perl/nginx.xs
+++ b/src/http/modules/perl/nginx.xs
@@ -125,9 +125,14 @@
ngx_http_request_t *r;
ngx_http_perl_ctx_t *ctx;
SV *sv;
+ ngx_int_t rc;
ngx_http_perl_set_request(r, ctx);
+ if (ctx->error) {
+ croak("send_http_header(): called after error");
+ }
+
if (r->headers_out.status == 0) {
r->headers_out.status = NGX_HTTP_OK;
}
@@ -151,7 +156,13 @@
r->disable_not_modified = 1;
- (void) ngx_http_send_header(r);
+ rc = ngx_http_send_header(r);
+
+ if (rc == NGX_ERROR || rc > NGX_OK) {
+ ctx->error = 1;
+ ctx->status = rc;
+ croak("ngx_http_send_header() failed");
+ }
void
@@ -381,6 +392,7 @@
dXSTARG;
ngx_http_request_t *r;
ngx_http_perl_ctx_t *ctx;
+ ngx_int_t rc;
ngx_http_perl_set_request(r, ctx);
@@ -398,7 +410,14 @@
r->request_body_file_log_level = 0;
}
- ngx_http_read_client_request_body(r, ngx_http_perl_handle_request);
+ rc = ngx_http_read_client_request_body(r, ngx_http_perl_handle_request);
+
+ if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
+ ctx->error = 1;
+ ctx->status = rc;
+ ctx->next = NULL;
+ croak("ngx_http_read_client_request_body() failed");
+ }
sv_upgrade(TARG, SVt_IV);
sv_setiv(TARG, 1);
@@ -494,10 +513,17 @@
ngx_http_request_t *r;
ngx_http_perl_ctx_t *ctx;
+ ngx_int_t rc;
ngx_http_perl_set_request(r, ctx);
- ngx_http_discard_request_body(r);
+ rc = ngx_http_discard_request_body(r);
+
+ if (rc != NGX_OK) {
+ ctx->error = 1;
+ ctx->status = rc;
+ croak("ngx_http_discard_request_body() failed");
+ }
void
@@ -512,6 +538,10 @@
ngx_http_perl_set_request(r, ctx);
+ if (ctx->error) {
+ croak("header_out(): called after error");
+ }
+
key = ST(1);
value = ST(2);
@@ -588,10 +618,15 @@
u_char *p;
size_t size;
STRLEN len;
+ ngx_int_t rc;
ngx_buf_t *b;
ngx_http_perl_set_request(r, ctx);
+ if (ctx->error) {
+ croak("print(): called after error");
+ }
+
if (items == 2) {
/*
@@ -671,7 +706,12 @@
out:
- (void) ngx_http_perl_output(r, ctx, b);
+ rc = ngx_http_perl_output(r, ctx, b);
+
+ if (rc == NGX_ERROR) {
+ ctx->error = 1;
+ croak("ngx_http_perl_output() failed");
+ }
void
@@ -683,6 +723,7 @@
char *filename;
off_t offset;
size_t bytes;
+ ngx_int_t rc;
ngx_str_t path;
ngx_buf_t *b;
ngx_open_file_info_t of;
@@ -690,6 +731,10 @@
ngx_http_perl_set_request(r, ctx);
+ if (ctx->error) {
+ croak("sendfile(): called after error");
+ }
+
filename = SvPV_nolen(ST(1));
if (filename == NULL) {
@@ -762,7 +807,12 @@
b->file->log = r->connection->log;
b->file->directio = of.is_directio;
- (void) ngx_http_perl_output(r, ctx, b);
+ rc = ngx_http_perl_output(r, ctx, b);
+
+ if (rc == NGX_ERROR) {
+ ctx->error = 1;
+ croak("ngx_http_perl_output() failed");
+ }
void
@@ -771,10 +821,15 @@
ngx_http_request_t *r;
ngx_http_perl_ctx_t *ctx;
+ ngx_int_t rc;
ngx_buf_t *b;
ngx_http_perl_set_request(r, ctx);
+ if (ctx->error) {
+ croak("flush(): called after error");
+ }
+
b = ngx_calloc_buf(r->pool);
if (b == NULL) {
XSRETURN_EMPTY;
@@ -784,7 +839,12 @@
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "$r->flush");
- (void) ngx_http_perl_output(r, ctx, b);
+ rc = ngx_http_perl_output(r, ctx, b);
+
+ if (rc == NGX_ERROR) {
+ ctx->error = 1;
+ croak("ngx_http_perl_output() failed");
+ }
XSRETURN_EMPTY;
diff --git a/src/http/modules/perl/ngx_http_perl_module.c b/src/http/modules/perl/ngx_http_perl_module.c
index c2ef470..ac6a7a2 100644
--- a/src/http/modules/perl/ngx_http_perl_module.c
+++ b/src/http/modules/perl/ngx_http_perl_module.c
@@ -246,6 +246,11 @@
ctx->filename.data = NULL;
ctx->redirect_uri.len = 0;
+ if (rc == NGX_ERROR) {
+ ngx_http_finalize_request(r, rc);
+ return;
+ }
+
if (ctx->done || ctx->next) {
ngx_http_finalize_request(r, NGX_DONE);
return;
@@ -690,6 +695,9 @@
status = 0;
+ ctx->error = 0;
+ ctx->status = NGX_OK;
+
ENTER;
SAVETMPS;
@@ -739,6 +747,18 @@
FREETMPS;
LEAVE;
+ if (ctx->error) {
+
+ ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
+ "call_sv: error, %d", ctx->status);
+
+ if (ctx->status != NGX_OK) {
+ return ctx->status;
+ }
+
+ return NGX_ERROR;
+ }
+
/* check $@ */
if (SvTRUE(ERRSV)) {
diff --git a/src/http/modules/perl/ngx_http_perl_module.h b/src/http/modules/perl/ngx_http_perl_module.h
index 4f1eaa3..5c967df 100644
--- a/src/http/modules/perl/ngx_http_perl_module.h
+++ b/src/http/modules/perl/ngx_http_perl_module.h
@@ -29,7 +29,10 @@
SV *next;
- ngx_uint_t done; /* unsigned done:1; */
+ ngx_int_t status;
+
+ unsigned done:1;
+ unsigned error:1;
ngx_array_t *variables; /* array of ngx_http_perl_var_t */
