altsvc: rewrite parser using strparse

Extend test 1654.

Closes #16454
This commit is contained in:
Daniel Stenberg 2025-02-24 15:29:13 +01:00
parent 5b5e2f7318
commit d485177151
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GPG Key ID: 5CC908FDB71E12C2
4 changed files with 135 additions and 144 deletions

View File

@ -407,26 +407,6 @@ CURLcode Curl_altsvc_save(struct Curl_easy *data,
return result;
}
static CURLcode getalnum(const char **ptr, char *alpnbuf, size_t buflen)
{
size_t len;
const char *protop;
const char *p = *ptr;
while(ISBLANK(*p))
p++;
protop = p;
while(*p && !ISBLANK(*p) && (*p != ';') && (*p != '='))
p++;
len = p - protop;
*ptr = p;
if(!len || (len >= buflen))
return CURLE_BAD_FUNCTION_ARGUMENT;
memcpy(alpnbuf, protop, len);
alpnbuf[len] = 0;
return CURLE_OK;
}
/* hostcompare() returns true if 'host' matches 'check'. The first host
* argument may have a trailing dot present that will be ignored.
*/
@ -497,144 +477,124 @@ CURLcode Curl_altsvc_parse(struct Curl_easy *data,
unsigned short srcport)
{
const char *p = value;
char alpnbuf[MAX_ALTSVC_ALPNLEN] = "";
struct altsvc *as;
unsigned short dstport = srcport; /* the same by default */
CURLcode result = getalnum(&p, alpnbuf, sizeof(alpnbuf));
size_t entries = 0;
size_t alpnlen = strlen(alpnbuf);
size_t srchostlen = strlen(srchost);
struct Curl_str alpn;
const char *sp;
time_t maxage = 24 * 3600; /* default is 24 hours */
bool persist = FALSE;
#ifdef CURL_DISABLE_VERBOSE_STRINGS
(void)data;
#endif
if(result) {
infof(data, "Excessive alt-svc header, ignoring.");
return CURLE_OK;
}
DEBUGASSERT(asi);
/* "clear" is a magic keyword */
if(strcasecompare(alpnbuf, "clear")) {
/* Flush cached alternatives for this source origin */
altsvc_flush(asi, srcalpnid, srchost, srcport);
return CURLE_OK;
/* initial check for "clear" */
if(!Curl_str_until(&p, &alpn, MAX_ALTSVC_LINE, ';') &&
!Curl_str_single(&p, ';')) {
Curl_str_trimblanks(&alpn);
/* "clear" is a magic keyword */
if(Curl_str_casecompare(&alpn, "clear")) {
/* Flush cached alternatives for this source origin */
altsvc_flush(asi, srcalpnid, srchost, srcport);
return CURLE_OK;
}
}
p = value;
if(Curl_str_until(&p, &alpn, MAX_ALTSVC_LINE, '='))
return CURLE_OK; /* strange line */
Curl_str_trimblanks(&alpn);
/* Handle the optional 'ma' and 'persist' flags once first, as they need to
be known for each alternative service. Unknown flags are skipped. */
sp = strchr(p, ';');
if(sp) {
sp++; /* pass the semicolon */
for(;;) {
struct Curl_str name;
struct Curl_str val;
const char *vp;
curl_off_t num;
bool quoted;
/* allow some extra whitespaces around name and value */
if(Curl_str_until(&sp, &name, 20, '=') ||
Curl_str_single(&sp, '=') ||
Curl_str_until(&sp, &val, 80, ';'))
break;
Curl_str_trimblanks(&name);
Curl_str_trimblanks(&val);
/* the value might be quoted */
vp = Curl_str(&val);
quoted = (*vp == '\"');
if(quoted)
vp++;
if(!Curl_str_number(&vp, &num, TIME_T_MAX)) {
if(Curl_str_casecompare(&name, "ma"))
maxage = (time_t)num;
else if(Curl_str_casecompare(&name, "persist") && (num == 1))
persist = TRUE;
}
if(quoted && Curl_str_single(&sp, '\"'))
break;
if(Curl_str_single(&sp, ';'))
break;
}
}
do {
if(*p == '=') {
/* [protocol]="[host][:port]" */
enum alpnid dstalpnid = Curl_alpn2alpnid(alpnbuf, alpnlen);
p++;
if(*p == '\"') {
const char *dsthost = "";
size_t dstlen = 0; /* destination hostname length */
const char *value_ptr;
char option[32];
curl_off_t num;
bool quoted = FALSE;
time_t maxage = 24 * 3600; /* default is 24 hours */
bool persist = FALSE;
bool valid = TRUE;
p++;
if(*p != ':') {
if(!Curl_str_single(&p, '=')) {
/* [protocol]="[host][:port], [protocol]="[host][:port]" */
enum alpnid dstalpnid =
Curl_alpn2alpnid(Curl_str(&alpn), Curl_strlen(&alpn));
if(!Curl_str_single(&p, '\"')) {
struct Curl_str dsthost;
curl_off_t port = 0;
if(Curl_str_single(&p, ':')) {
/* hostname starts here */
const char *hostp = p;
if(*p == '[') {
/* pass all valid IPv6 letters - does not handle zone id */
dstlen = strspn(++p, "0123456789abcdefABCDEF:.");
if(p[dstlen] != ']')
/* invalid host syntax, bail out */
if(Curl_str_single(&p, '[')) {
if(Curl_str_until(&p, &dsthost, MAX_ALTSVC_HOSTLEN, ':')) {
infof(data, "Bad alt-svc hostname, ignoring.");
break;
/* we store the IPv6 numerical address *with* brackets */
dstlen += 2;
p = &p[dstlen-1];
}
}
else {
while(*p && (ISALNUM(*p) || (*p == '.') || (*p == '-')))
p++;
dstlen = p - hostp;
}
if(!dstlen || (dstlen >= MAX_ALTSVC_HOSTLEN)) {
infof(data, "Excessive alt-svc hostname, ignoring.");
valid = FALSE;
}
else {
dsthost = hostp;
/* IPv6 host name */
if(Curl_str_until(&p, &dsthost, MAX_IPADR_LEN, ']') ||
Curl_str_single(&p, ']')) {
infof(data, "Bad alt-svc IPv6 hostname, ignoring.");
break;
}
}
if(Curl_str_single(&p, ':'))
break;
}
else {
else
/* no destination name, use source host */
dsthost = srchost;
dstlen = strlen(srchost);
}
if(*p == ':') {
curl_off_t port = 0;
p++;
if(Curl_str_number(&p, &port, 0xffff) || (*p != '\"')) {
infof(data, "Unknown alt-svc port number, ignoring.");
valid = FALSE;
}
else
dstport = (unsigned short)port;
}
if(*p++ != '\"')
Curl_str_assign(&dsthost, srchost, strlen(srchost));
if(Curl_str_number(&p, &port, 0xffff)) {
infof(data, "Unknown alt-svc port number, ignoring.");
break;
/* Handle the optional 'ma' and 'persist' flags. Unknown flags
are skipped. */
for(;;) {
while(ISBLANK(*p))
p++;
if(*p != ';')
break;
p++; /* pass the semicolon */
if(!*p || ISNEWLINE(*p))
break;
result = getalnum(&p, option, sizeof(option));
if(result) {
/* skip option if name is too long */
option[0] = '\0';
}
while(ISBLANK(*p))
p++;
if(*p != '=')
return CURLE_OK;
p++;
while(ISBLANK(*p))
p++;
if(!*p)
return CURLE_OK;
if(*p == '\"') {
/* quoted value */
p++;
quoted = TRUE;
}
value_ptr = p;
if(quoted) {
while(*p && *p != '\"')
p++;
if(!*p++)
return CURLE_OK;
}
else {
while(*p && !ISBLANK(*p) && *p!= ';' && *p != ',')
p++;
}
if(!Curl_str_number(&value_ptr, &num, TIME_T_MAX)) {
if(strcasecompare("ma", option))
maxage = (time_t)num;
else if(strcasecompare("persist", option) && (num == 1))
persist = TRUE;
}
}
if(dstalpnid && valid) {
dstport = (unsigned short)port;
if(Curl_str_single(&p, '\"'))
break;
if(dstalpnid) {
if(!entries++)
/* Flush cached alternatives for this source origin, if any - when
this is the first entry of the line. */
altsvc_flush(asi, srcalpnid, srchost, srcport);
as = altsvc_createid(srchost, srchostlen,
dsthost, dstlen,
as = altsvc_createid(srchost, strlen(srchost),
Curl_str(&dsthost),
Curl_strlen(&dsthost),
srcalpnid, dstalpnid,
srcport, dstport);
if(as) {
@ -647,26 +607,28 @@ CURLcode Curl_altsvc_parse(struct Curl_easy *data,
as->expires = maxage + secs;
as->persist = persist;
Curl_llist_append(&asi->list, as, &as->node);
infof(data, "Added alt-svc: %s:%d over %s", dsthost, dstport,
Curl_alpnid2str(dstalpnid));
infof(data, "Added alt-svc: %.*s:%d over %s",
(int)Curl_strlen(&dsthost), Curl_str(&dsthost),
dstport, Curl_alpnid2str(dstalpnid));
}
}
}
else
break;
/* after the double quote there can be a comma if there is another
string or a semicolon if no more */
if(*p == ',') {
/* comma means another alternative is presented */
p++;
result = getalnum(&p, alpnbuf, sizeof(alpnbuf));
if(result)
break;
}
if(Curl_str_single(&p, ','))
break;
/* comma means another alternative is present */
if(Curl_str_until(&p, &alpn, MAX_ALTSVC_LINE, '='))
break;
Curl_str_trimblanks(&alpn);
}
else
break;
} while(*p && (*p != ';') && (*p != '\n') && (*p != '\r'));
} while(1);
return CURLE_OK;
}

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@ -31,6 +31,12 @@ void Curl_str_init(struct Curl_str *out)
out->len = 0;
}
void Curl_str_assign(struct Curl_str *out, const char *str, size_t len)
{
out->str = str;
out->len = len;
}
/* Get a word until the first DELIM or end of string. At least one byte long.
return non-zero on error */
int Curl_str_until(const char **linep, struct Curl_str *out,

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@ -43,6 +43,7 @@ struct Curl_str {
};
void Curl_str_init(struct Curl_str *out);
void Curl_str_assign(struct Curl_str *out, const char *str, size_t len);
#define Curl_str(x) ((x)->str)
#define Curl_strlen(x) ((x)->len)

View File

@ -71,7 +71,8 @@ UNITTEST_START
fail_unless(Curl_llist_count(&asi->list) == 6, "wrong number of entries");
result = Curl_altsvc_parse(curl, asi,
"h2=\"example.com:8080\", h3=\"yesyes.com\"\r\n",
"h2=\"example.com:8080\", "
"h3=\"yesyes.com:8080\"\r\n",
ALPN_h1, "3.example.org", 8080);
fail_if(result, "Curl_altsvc_parse(3) failed!");
/* that one should make two entries */
@ -92,7 +93,8 @@ UNITTEST_START
result =
Curl_altsvc_parse(curl, asi,
"h2=\":443\", h3=\":443\"; ma = 120; persist = 1\r\n",
"h2=\":443\", h3=\":443\"; "
"persist = \"1\"; ma = 120;\r\n",
ALPN_h1, "curl.se", 80);
fail_if(result, "Curl_altsvc_parse(5) failed!");
fail_unless(Curl_llist_count(&asi->list) == 12, "wrong number of entries");
@ -103,6 +105,26 @@ UNITTEST_START
fail_if(result, "Curl_altsvc_parse(6) failed!");
fail_unless(Curl_llist_count(&asi->list) == 10, "wrong number of entries");
/* only a non-existing alpn */
result = Curl_altsvc_parse(curl, asi,
"h6=\"example.net:443\"; ma=\"180\";\r\n",
ALPN_h2, "5.example.net", 80);
/* missing quote in alpn host */
result = Curl_altsvc_parse(curl, asi,
"h2=\"example.net:443,; ma=\"180\";\r\n",
ALPN_h2, "6.example.net", 80);
/* missing port in host name */
result = Curl_altsvc_parse(curl, asi,
"h2=\"example.net\"; ma=\"180\";\r\n",
ALPN_h2, "7.example.net", 80);
/* illegal port in host name */
result = Curl_altsvc_parse(curl, asi,
"h2=\"example.net:70000\"; ma=\"180\";\r\n",
ALPN_h2, "8.example.net", 80);
Curl_altsvc_save(curl, asi, outname);
curl_easy_cleanup(curl);