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Use dprintf() instead of snprintf()+sendbuffer()

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The aim was to write quark without any mallocs. This was successful, but
proved to be a bit ugly looking at how we construct data to be sent.
Before this change, we had static buffers in each function that needed
them and filled them up, possibly risking overflow.
After that, we sent them off using our own function sendbuffer(), which
in itself represented a buffering mechanism.
Using dprintf, which is POSIX 2008, we can send things off directly,
with no need for sendbuffer() or buffers for these things.
This way we can factor out sendbuffer(), dropping a few more LOCs.

Thanks Hiltjo for the suggestion!
This commit is contained in:
Laslo Hunhold 2017-06-21 07:41:52 +02:00
parent 6347e2ec3e
commit f4db83f68c
1 changed files with 73 additions and 99 deletions
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172
quark.c
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@ -160,42 +160,28 @@ encode(char src[PATH_MAX], char dest[PATH_MAX])
return 0;
}
static int
sendbuffer(int fd, char *buf, size_t buflen) {
size_t written;
ssize_t off;
for (written = 0; buflen > 0; written += off, buflen -= off) {
if ((off = write(fd, buf + written, buflen)) < 0) {
return 1;
}
}
return 0;
}
static enum status
sendstatus(int fd, enum status s)
{
static char res[4096], t[TIMESTAMP_LEN];
size_t len;
static char t[TIMESTAMP_LEN];
/* assemble error response */
len = snprintf(res, sizeof(res),
"HTTP/1.1 %d %s\r\n"
"Date: %s\r\n"
"Connection: close\r\n"
"%s"
"Content-Type: text/html\r\n"
"\r\n"
"<!DOCTYPE html>\n<html>\n\t<head>\n"
"\t\t<title>%d %s</title>\n\t</head>\n\t<body>\n"
"\t\t<h1>%d %s</h1>\n\t</body>\n</html>",
s, status_str[s], timestamp(0, t),
(s == S_METHOD_NOT_ALLOWED) ? "Allow: HEAD, GET\r\n" : "",
s, status_str[s], s, status_str[s]);
if (dprintf(fd,
"HTTP/1.1 %d %s\r\n"
"Date: %s\r\n"
"Connection: close\r\n"
"%s"
"Content-Type: text/html\r\n"
"\r\n"
"<!DOCTYPE html>\n<html>\n\t<head>\n"
"\t\t<title>%d %s</title>\n\t</head>\n\t<body>\n"
"\t\t<h1>%d %s</h1>\n\t</body>\n</html>",
s, status_str[s], timestamp(0, t),
(s == S_METHOD_NOT_ALLOWED) ? "Allow: HEAD, GET\r\n" : "",
s, status_str[s], s, status_str[s]) < 0) {
return S_REQUEST_TIMEOUT;
}
return sendbuffer(fd, res, len) ? S_REQUEST_TIMEOUT : s;
return s;
}
static int
@ -347,9 +333,9 @@ static enum status
senddir(int fd, char *name, struct request *r)
{
struct dirent **e;
size_t len, i;
size_t i;
int dirlen;
static char resheader[HEADER_MAX], buf[BUFSIZ], t[TIMESTAMP_LEN];
static char t[TIMESTAMP_LEN];
/* read directory */
if ((dirlen = scandir(name, &e, NULL, alphasort)) < 0) {
@ -357,28 +343,23 @@ senddir(int fd, char *name, struct request *r)
}
/* send header as late as possible */
len = snprintf(resheader, sizeof(resheader),
"HTTP/1.1 %d %s\r\n"
"Date: %s\r\n"
"Connection: close\r\n"
"Content-Type: text/html\r\n"
"\r\n",
S_OK, status_str[S_OK], timestamp(0, t));
if (sendbuffer(fd, resheader, len)) {
if (dprintf(fd,
"HTTP/1.1 %d %s\r\n"
"Date: %s\r\n"
"Connection: close\r\n"
"Content-Type: text/html\r\n"
"\r\n",
S_OK, status_str[S_OK], timestamp(0, t)) < 0) {
return S_REQUEST_TIMEOUT;
}
if (r->method == M_GET) {
/* listing header */
if ((len = snprintf(buf, sizeof(buf),
"<!DOCTYPE html>\n<html>\n\t<head>"
"<title>Index of %s</title></head>\n"
"\t<body>\n\t\t<a href=\"..\">..</a>",
name)) >= sizeof(buf)) {
return S_INTERNAL_SERVER_ERROR;
}
if (sendbuffer(fd, buf, len)) {
if (dprintf(fd,
"<!DOCTYPE html>\n<html>\n\t<head>"
"<title>Index of %s</title></head>\n"
"\t<body>\n\t\t<a href=\"..\">..</a>",
name) < 0) {
return S_REQUEST_TIMEOUT;
}
@ -390,20 +371,14 @@ senddir(int fd, char *name, struct request *r)
}
/* entry line */
if ((len = snprintf(buf, sizeof(buf),
"<br />\n\t\t<a href=\"%s\">%s</a>",
e[i]->d_name, e[i]->d_name))
>= sizeof(buf)) {
return S_INTERNAL_SERVER_ERROR;
}
if (sendbuffer(fd, buf, len)) {
if (dprintf(fd, "<br />\n\t\t<a href=\"%s\">%s</a>",
e[i]->d_name, e[i]->d_name) < 0) {
return S_REQUEST_TIMEOUT;
}
}
/* listing footer */
if (sendbuffer(fd, "\n\t</body>\n</html>",
sizeof("\n\t</body>\n</html>") - 1)) {
if (dprintf(fd, "\n\t</body>\n</html>") < 0) {
return S_REQUEST_TIMEOUT;
}
}
@ -417,12 +392,10 @@ sendfile(int fd, char *name, struct request *r, struct stat *st, char *mime,
{
FILE *fp;
enum status s;
size_t len;
ssize_t bread, bwritten;
off_t remaining;
int range;
static char resheader[HEADER_MAX], buf[BUFSIZ], *p, t1[TIMESTAMP_LEN],
t2[TIMESTAMP_LEN];
static char buf[BUFSIZ], *p, t1[TIMESTAMP_LEN], t2[TIMESTAMP_LEN];
/* open file */
if (!(fp = fopen(name, "r"))) {
@ -438,23 +411,24 @@ sendfile(int fd, char *name, struct request *r, struct stat *st, char *mime,
range = r->field[REQ_RANGE][0];
s = range ? S_PARTIAL_CONTENT : S_OK;
len = snprintf(resheader, sizeof(resheader),
"HTTP/1.1 %d %s\r\n"
"Date: %s\r\n"
"Connection: close\r\n"
"Last-Modified: %s\r\n"
"Content-Type: %s\r\n"
"Content-Length: %zu\r\n",
s, status_str[s], timestamp(0, t1),
timestamp(st->st_mtim.tv_sec, t2), mime, upper - lower);
if (range) {
len += snprintf(resheader + len, sizeof(resheader) - len,
"Content-Range: bytes %zu-%zu/%zu\r\n",
lower, upper - 1, st->st_size);
if (dprintf(fd,
"HTTP/1.1 %d %s\r\n"
"Date: %s\r\n"
"Connection: close\r\n"
"Last-Modified: %s\r\n"
"Content-Type: %s\r\n"
"Content-Length: %zu\r\n",
s, status_str[s], timestamp(0, t1),
timestamp(st->st_mtim.tv_sec, t2), mime, upper - lower) < 0) {
return S_REQUEST_TIMEOUT;
}
len += snprintf(resheader + len, sizeof(resheader) - len, "\r\n");
if (sendbuffer(fd, resheader, len)) {
if (range) {
if (dprintf(fd, "Content-Range: bytes %zu-%zu/%zu\r\n",
lower, upper - 1, st->st_size) < 0) {
return S_REQUEST_TIMEOUT;
}
}
if (dprintf(fd, "\r\n") < 0) {
return S_REQUEST_TIMEOUT;
}
@ -489,8 +463,7 @@ sendresponse(int fd, struct request *r)
struct tm tm;
size_t len, i;
off_t lower, upper;
static char realtarget[PATH_MAX], resheader[HEADER_MAX],
tmptarget[PATH_MAX], t[TIMESTAMP_LEN];
static char realtarget[PATH_MAX], tmptarget[PATH_MAX], t[TIMESTAMP_LEN];
char *p, *q, *mime;
/* check method */
@ -530,17 +503,19 @@ sendresponse(int fd, struct request *r)
/* encode realtarget */
encode(realtarget, tmptarget);
len = snprintf(resheader, sizeof(resheader),
"HTTP/1.1 %d %s\r\n"
"Date: %s\r\n"
"Connection: close\r\n"
"Location: %s\r\n"
"\r\n",
S_MOVED_PERMANENTLY,
status_str[S_MOVED_PERMANENTLY], timestamp(0, t),
tmptarget);
return sendbuffer(fd, resheader, len) ? S_REQUEST_TIMEOUT :
S_MOVED_PERMANENTLY;
if (dprintf(fd,
"HTTP/1.1 %d %s\r\n"
"Date: %s\r\n"
"Connection: close\r\n"
"Location: %s\r\n"
"\r\n",
S_MOVED_PERMANENTLY,
status_str[S_MOVED_PERMANENTLY], timestamp(0, t),
tmptarget) < 0) {
return S_REQUEST_TIMEOUT;
}
return S_MOVED_PERMANENTLY;
}
if (S_ISDIR(st.st_mode)) {
@ -577,14 +552,13 @@ sendresponse(int fd, struct request *r)
/* compare with last modification date of the file */
if (difftime(st.st_mtim.tv_sec, mktime(&tm)) <= 0) {
len = snprintf(resheader, sizeof(resheader),
"HTTP/1.1 %d %s\r\n"
"Date: %s\r\n"
"Connection: close\r\n"
"\r\n",
S_NOT_MODIFIED, status_str[S_NOT_MODIFIED],
timestamp(0, t));
if (sendbuffer(fd, resheader, len)) {
if (dprintf(fd,
"HTTP/1.1 %d %s\r\n"
"Date: %s\r\n"
"Connection: close\r\n"
"\r\n",
S_NOT_MODIFIED, status_str[S_NOT_MODIFIED],
timestamp(0, t)) < 0) {
return S_REQUEST_TIMEOUT;
}
}