MINOR: http-htx: Add understandable errors for the errorfiles parsing

No details are provided when an error occurs during the parsing of an errorfile,
Thus it is a bit hard to diagnose where the problem is. Now, when it happens, an
understandable error message is reported.

This patch is not a bug fix in itself. But it will be required to change an
fatal error into a warning in last stable releases. Thus it must be backported
as far as 2.0.

diff --git a/include/haproxy/http_htx.h b/include/haproxy/http_htx.h
index f90b4cc74786b9bbd2c82f8c25c2f29a7598c982..70df6806f05e879f719c0e0e0ed7b007139f076a 100644 (file)
--- a/include/haproxy/http_htx.h
+++ b/include/haproxy/http_htx.h
@@ -59,7 +59,7 @@ unsigned int http_get_htx_hdr(const struct htx *htx, const struct ist hdr,
                              int occ, struct http_hdr_ctx *ctx, char **vptr, size_t *vlen);
 unsigned int http_get_htx_fhdr(const struct htx *htx, const struct ist hdr,
                               int occ, struct http_hdr_ctx *ctx, char **vptr, size_t *vlen);
-int http_str_to_htx(struct buffer *buf, struct ist raw);
+int http_str_to_htx(struct buffer *buf, struct ist raw, char **errmsg);
 
 void release_http_reply(struct http_reply *http_reply);
 int http_check_http_reply(struct http_reply *reply, struct proxy*px, char **errmsg);

diff --git a/src/http_htx.c b/src/http_htx.c
index cb52b06f0d102a22927ee04ba0bac7600cac090b..ed493197ed1e430a87f87343241adec85990b110 100644 (file)
--- a/src/http_htx.c
+++ b/src/http_htx.c
@@ -891,7 +891,7 @@ unsigned int http_get_htx_fhdr(const struct htx *htx, const struct ist hdr,
        return 1;
 }
 
-int http_str_to_htx(struct buffer *buf, struct ist raw)
+int http_str_to_htx(struct buffer *buf, struct ist raw, char **errmsg)
 {
        struct htx *htx;
        struct htx_sl *sl;
@@ -917,17 +917,24 @@ int http_str_to_htx(struct buffer *buf, struct ist raw)
        h1m.flags |= H1_MF_NO_PHDR;
        ret = h1_headers_to_hdr_list(raw.ptr, raw.ptr + raw.len,
                                     hdrs, sizeof(hdrs)/sizeof(hdrs[0]), &h1m, &h1sl);
-       if (ret <= 0)
+       if (ret <= 0) {
+               memprintf(errmsg, "unabled to parse headers (error offset: %d)", h1m.err_pos);
                goto error;
+       }
 
-       if (unlikely(h1sl.st.v.len != 8))
+       if (unlikely(h1sl.st.v.len != 8)) {
+               memprintf(errmsg, "invalid http version (%.*s)", (int)h1sl.st.v.len, h1sl.st.v.ptr);
                goto error;
+       }
        if ((*(h1sl.st.v.ptr + 5) > '1') ||
            ((*(h1sl.st.v.ptr + 5) == '1') && (*(h1sl.st.v.ptr + 7) >= '1')))
                h1m.flags |= H1_MF_VER_11;
 
-       if (h1sl.st.status < 200 && (h1sl.st.status == 100 || h1sl.st.status >= 102))
+       if (h1sl.st.status < 200 && (h1sl.st.status == 100 || h1sl.st.status >= 102)) {
+               memprintf(errmsg, "invalid http status code for an error message (%u)",
+                         h1sl.st.status);
                goto error;
+       }
 
        if (h1sl.st.status == 204 || h1sl.st.status == 304) {
                /* Responses known to have no body. */
@@ -944,8 +951,10 @@ int http_str_to_htx(struct buffer *buf, struct ist raw)
                flags |= HTX_SL_F_XFER_ENC;
        if (h1m.flags & H1_MF_XFER_LEN) {
                flags |= HTX_SL_F_XFER_LEN;
-               if (h1m.flags & H1_MF_CHNK)
-                       goto error; /* Unsupported because there is no body parsing */
+               if (h1m.flags & H1_MF_CHNK) {
+                       memprintf(errmsg, "chunk-encoded payload not supported");
+                       goto error;
+               }
                else if (h1m.flags & H1_MF_CLEN) {
                        flags |= HTX_SL_F_CLEN;
                        if (h1m.body_len == 0)
@@ -955,26 +964,37 @@ int http_str_to_htx(struct buffer *buf, struct ist raw)
                        flags |= HTX_SL_F_BODYLESS;
        }
 
-       if ((flags & HTX_SL_F_BODYLESS) && raw.len > ret)
-               goto error; /* No body expected */
-       if ((flags & HTX_SL_F_CLEN) && h1m.body_len != (raw.len - ret))
-               goto error; /* body with wrong length */
+       if ((flags & HTX_SL_F_BODYLESS) && raw.len > ret) {
+               memprintf(errmsg, "message payload not expected");
+               goto error;
+       }
+       if ((flags & HTX_SL_F_CLEN) && h1m.body_len != (raw.len - ret)) {
+               memprintf(errmsg, "payload size does not match the announced content-length (%lu != %lu)",
+                         (raw.len - ret), h1m.body_len);
+               goto error;
+       }
 
        htx = htx_from_buf(buf);
        sl = htx_add_stline(htx, HTX_BLK_RES_SL, flags, h1sl.st.v, h1sl.st.c, h1sl.st.r);
-       if (!sl || !htx_add_all_headers(htx, hdrs))
+       if (!sl || !htx_add_all_headers(htx, hdrs)) {
+               memprintf(errmsg, "unable to add headers into the HTX message");
                goto error;
+       }
        sl->info.res.status = h1sl.st.status;
 
        while (raw.len > ret) {
                int sent = htx_add_data(htx, ist2(raw.ptr + ret, raw.len - ret));
-               if (!sent)
+               if (!sent) {
+                       memprintf(errmsg, "unable to add payload into the HTX message");
                        goto error;
+               }
                ret += sent;
        }
 
-       if (!htx_add_endof(htx, HTX_BLK_EOM))
+       if (!htx_add_endof(htx, HTX_BLK_EOM)) {
+               memprintf(errmsg, "unable to add EOM into the HTX message");
                goto error;
+       }
 
        return 1;
 
@@ -1027,22 +1047,32 @@ static int http_htx_init(void)
 {
        struct buffer chk;
        struct ist raw;
+       char *errmsg = NULL;
        int rc;
        int err_code = 0;
 
        for (rc = 0; rc < HTTP_ERR_SIZE; rc++) {
                if (!http_err_msgs[rc]) {
-                       ha_alert("Internal error: no message defined for HTTP return code %d", rc);
+                       ha_alert("Internal error: no default message defined for HTTP return code %d", rc);
                        err_code |= ERR_ALERT | ERR_FATAL;
                        continue;
                }
 
                raw = ist2(http_err_msgs[rc], strlen(http_err_msgs[rc]));
-               if (!http_str_to_htx(&chk, raw)) {
-                       ha_alert("Internal error: Unable to convert message in HTX for HTTP return code %d.\n",
-                                http_err_codes[rc]);
+               if (!http_str_to_htx(&chk, raw, &errmsg)) {
+                       ha_alert("Internal error: invalid default message for HTTP return code %d: %s.\n",
+                                http_err_codes[rc], errmsg);
                        err_code |= ERR_ALERT | ERR_FATAL;
                }
+               else if (errmsg) {
+                       ha_warning("invalid default message for HTTP return code %d: %s.\n", http_err_codes[rc], errmsg);
+                       err_code |= ERR_WARN;
+               }
+
+               /* Reset errmsg */
+               free(errmsg);
+               errmsg = NULL;
+
                http_err_chunks[rc] = chk;
                http_err_replies[rc].type = HTTP_REPLY_ERRMSG;
                http_err_replies[rc].status = http_err_codes[rc];
@@ -1155,8 +1185,8 @@ struct buffer *http_load_errorfile(const char *file, char **errmsg)
        }
 
        /* Convert the error file into an HTX message */
-       if (!http_str_to_htx(&chk, ist2(err, errlen))) {
-               memprintf(errmsg, "unable to convert custom error message file '%s' in HTX.", file);
+       if (!http_str_to_htx(&chk, ist2(err, errlen), errmsg)) {
+               memprintf(errmsg, "'%s': %s", file, *errmsg);
                free(http_errmsg->node.key);
                free(http_errmsg);
                goto out;
@@ -1206,8 +1236,8 @@ struct buffer *http_load_errormsg(const char *key, const struct ist msg, char **
        }
 
        /* Convert the error file into an HTX message */
-       if (!http_str_to_htx(&chk, msg)) {
-               memprintf(errmsg, "unable to convert message in HTX.");
+       if (!http_str_to_htx(&chk, msg, errmsg)) {
+               memprintf(errmsg, "invalid error message: %s", *errmsg);
                free(http_errmsg->node.key);
                free(http_errmsg);
                goto out;
@@ -1757,6 +1787,9 @@ static int proxy_parse_errorloc(char **args, int section, struct proxy *curpx,
        conf_err->line = line;
        LIST_ADDQ(&curpx->conf.errors, &conf_err->list);
 
+       /* handle warning message */
+       if (*errmsg)
+               ret = 1;
   out:
        return ret;
 
@@ -1819,6 +1852,9 @@ static int proxy_parse_errorfile(char **args, int section, struct proxy *curpx,
        conf_err->line = line;
        LIST_ADDQ(&curpx->conf.errors, &conf_err->list);
 
+       /* handle warning message */
+       if (*errmsg)
+               ret = 1;
   out:
        return ret;