commit a5163d08135b81b271b1d7ba36b24e342b57961f
parent c1b242e405d40067c282e8116d21c6f2641e4eee
Author: Laslo Hunhold <dev@frign.de>
Date: Sat, 22 Aug 2020 11:05:20 +0200
Split up http_get_request()
The function has become too long and basically did two things: Receiving
the header and parsing it. To better reflect this, we split it up into
the two functions http_recv_header() and http_parse_header(). This way,
we also obtain a better separation of concerns and can further reduce
the scope of each parameter-list.
http_recv_header() has been written in such a way that it can be
reentered and fill up the header-buffer bit by bit using a pointer to
an offset value.
The error handling was improved by only returning the immediate error
status codes and letting the caller do the error-handling with
http_send_status().
Signed-off-by: Laslo Hunhold <dev@frign.de>
Diffstat:
| M | http.c | | | 120 | ++++++++++++++++++++++++++++++++++++++++++------------------------------------- |
| M | http.h | | | 3 | ++- |
| M | main.c | | | 6 | +++++- |
3 files changed, 71 insertions(+), 58 deletions(-)
diff --git a/http.c b/http.c
@@ -143,43 +143,51 @@ decode(const char src[PATH_MAX], char dest[PATH_MAX])
dest[i] = '\0';
}
-int
-http_get_request(int fd, struct request *req)
+enum status
+http_recv_header(int fd, char *h, size_t hsiz, size_t *off)
{
- struct in6_addr addr;
- size_t hlen, i, mlen;
- ssize_t off;
- char *h = req->header, *p, *q;
+ ssize_t r;
- /* empty all fields */
- memset(req, 0, sizeof(*req));
+ if (h == NULL || off == NULL || *off > hsiz) {
+ return S_INTERNAL_SERVER_ERROR;
+ }
- /*
- * receive header
- */
- for (hlen = 0; ;) {
- if ((off = read(fd, h + hlen, sizeof(h) - hlen)) < 0) {
- return http_send_status(fd, S_REQUEST_TIMEOUT);
- } else if (off == 0) {
- break;
+ while (1) {
+ if ((r = read(fd, h + *off, hsiz - *off)) <= 0) {
+ return S_REQUEST_TIMEOUT;
}
- hlen += off;
- if (hlen >= 4 && !memcmp(h + hlen - 4, "\r\n\r\n", 4)) {
+ *off += r;
+
+ /* check if we are done (header terminated) */
+ if (*off >= 4 && !memcmp(h + *off - 4, "\r\n\r\n", 4)) {
break;
}
- if (hlen == sizeof(h)) {
- return http_send_status(fd, S_REQUEST_TOO_LARGE);
+
+ /* buffer is full or read over, but header is not terminated */
+ if (r == 0 || *off == hsiz) {
+ return S_REQUEST_TOO_LARGE;
}
}
- /* remove terminating empty line */
- if (hlen < 2) {
- return http_send_status(fd, S_BAD_REQUEST);
- }
- hlen -= 2;
+ /* header is complete, remove last \r\n and null-terminate */
+ h[*off - 2] = '\0';
+
+ /* set *off to 0 to indicate we are finished */
+ *off = 0;
- /* null-terminate the header */
- h[hlen] = '\0';
+ return 0;
+}
+
+enum status
+http_parse_header(const char *h, struct request *req)
+{
+ struct in6_addr addr;
+ size_t i, mlen;
+ const char *p, *q;
+ char *m, *n;
+
+ /* empty all fields */
+ memset(req, 0, sizeof(*req));
/*
* parse request line
@@ -194,12 +202,12 @@ http_get_request(int fd, struct request *req)
}
}
if (i == NUM_REQ_METHODS) {
- return http_send_status(fd, S_METHOD_NOT_ALLOWED);
+ return S_METHOD_NOT_ALLOWED;
}
/* a single space must follow the method */
if (h[mlen] != ' ') {
- return http_send_status(fd, S_BAD_REQUEST);
+ return S_BAD_REQUEST;
}
/* basis for next step */
@@ -207,13 +215,13 @@ http_get_request(int fd, struct request *req)
/* TARGET */
if (!(q = strchr(p, ' '))) {
- return http_send_status(fd, S_BAD_REQUEST);
+ return S_BAD_REQUEST;
}
- *q = '\0';
if (q - p + 1 > PATH_MAX) {
- return http_send_status(fd, S_REQUEST_TOO_LARGE);
+ return S_REQUEST_TOO_LARGE;
}
- memcpy(req->target, p, q - p + 1);
+ memcpy(req->target, p, q - p);
+ req->target[q - p] = '\0';
decode(req->target, req->target);
/* basis for next step */
@@ -221,18 +229,18 @@ http_get_request(int fd, struct request *req)
/* HTTP-VERSION */
if (strncmp(p, "HTTP/", sizeof("HTTP/") - 1)) {
- return http_send_status(fd, S_BAD_REQUEST);
+ return S_BAD_REQUEST;
}
p += sizeof("HTTP/") - 1;
if (strncmp(p, "1.0", sizeof("1.0") - 1) &&
strncmp(p, "1.1", sizeof("1.1") - 1)) {
- return http_send_status(fd, S_VERSION_NOT_SUPPORTED);
+ return S_VERSION_NOT_SUPPORTED;
}
p += sizeof("1.*") - 1;
/* check terminator */
if (strncmp(p, "\r\n", sizeof("\r\n") - 1)) {
- return http_send_status(fd, S_BAD_REQUEST);
+ return S_BAD_REQUEST;
}
/* basis for next step */
@@ -253,7 +261,7 @@ http_get_request(int fd, struct request *req)
if (i == NUM_REQ_FIELDS) {
/* unmatched field, skip this line */
if (!(q = strstr(p, "\r\n"))) {
- return http_send_status(fd, S_BAD_REQUEST);
+ return S_BAD_REQUEST;
}
p = q + (sizeof("\r\n") - 1);
continue;
@@ -263,7 +271,7 @@ http_get_request(int fd, struct request *req)
/* a single colon must follow the field name */
if (*p != ':') {
- return http_send_status(fd, S_BAD_REQUEST);
+ return S_BAD_REQUEST;
}
/* skip whitespace */
@@ -272,13 +280,13 @@ http_get_request(int fd, struct request *req)
/* extract field content */
if (!(q = strstr(p, "\r\n"))) {
- return http_send_status(fd, S_BAD_REQUEST);
+ return S_BAD_REQUEST;
}
- *q = '\0';
if (q - p + 1 > FIELD_MAX) {
- return http_send_status(fd, S_REQUEST_TOO_LARGE);
+ return S_REQUEST_TOO_LARGE;
}
- memcpy(req->field[i], p, q - p + 1);
+ memcpy(req->field[i], p, q - p);
+ req->field[i][q - p] = '\0';
/* go to next line */
p = q + (sizeof("\r\n") - 1);
@@ -288,37 +296,37 @@ http_get_request(int fd, struct request *req)
* clean up host
*/
- p = strrchr(req->field[REQ_HOST], ':');
- q = strrchr(req->field[REQ_HOST], ']');
+ m = strrchr(req->field[REQ_HOST], ':');
+ n = strrchr(req->field[REQ_HOST], ']');
/* strip port suffix but don't interfere with IPv6 bracket notation
* as per RFC 2732 */
- if (p && (!q || p > q)) {
+ if (m && (!n || m > n)) {
/* port suffix must not be empty */
- if (*(p + 1) == '\0') {
- return http_send_status(fd, S_BAD_REQUEST);
+ if (*(m + 1) == '\0') {
+ return S_BAD_REQUEST;
}
- *p = '\0';
+ *m = '\0';
}
/* strip the brackets from the IPv6 notation and validate the address */
- if (q) {
+ if (n) {
/* brackets must be on the outside */
- if (req->field[REQ_HOST][0] != '[' || *(q + 1) != '\0') {
- return http_send_status(fd, S_BAD_REQUEST);
+ if (req->field[REQ_HOST][0] != '[' || *(n + 1) != '\0') {
+ return S_BAD_REQUEST;
}
/* remove the right bracket */
- *q = '\0';
- p = req->field[REQ_HOST] + 1;
+ *n = '\0';
+ m = req->field[REQ_HOST] + 1;
/* validate the contained IPv6 address */
- if (inet_pton(AF_INET6, p, &addr) != 1) {
- return http_send_status(fd, S_BAD_REQUEST);
+ if (inet_pton(AF_INET6, m, &addr) != 1) {
+ return S_BAD_REQUEST;
}
/* copy it into the host field */
- memmove(req->field[REQ_HOST], p, q - p + 1);
+ memmove(req->field[REQ_HOST], m, n - m + 1);
}
return 0;
diff --git a/http.h b/http.h
@@ -104,7 +104,8 @@ struct connection {
enum status http_send_header(int, const struct response *);
enum status http_send_status(int, enum status);
-int http_get_request(int fd, struct request *);
+enum status http_recv_header(int, char *, size_t, size_t *);
+enum status http_parse_header(const char *, struct request *);
enum status http_send_response(int fd, const struct request *,
const struct server *);
diff --git a/main.c b/main.c
@@ -37,7 +37,11 @@ serve(int infd, const struct sockaddr_storage *in_sa, const struct server *s)
}
/* handle request */
- if (!(status = http_get_request(c.fd, &c.req))) {
+ if ((status = http_recv_header(c.fd, c.header, LEN(c.header), &c.off))) {
+ status = http_send_status(c.fd, status);
+ } else if ((status = http_parse_header(c.header, &c.req))) {
+ status = http_send_status(c.fd, status);
+ } else {
status = http_send_response(c.fd, &c.req, s);
}
