On Tue, Apr 16, 2024 at 07:07:14PM +0200, Tobias Heider wrote:
> We'll need this in got-fetch-http
> 
> -----------------------------------------------
> commit 98fc2289f1bf714314940fbb725d95ea15ced3f1 (xdigit)
> from: Tobias Heider <me@tobhe.de>
> date: Tue Apr 16 16:30:10 2024 UTC
>  
>  Make got_pkt_readlen() a separate function. There are multiple
>  places where we need to parse strings with the same format.

ok stsp@

> diff 3bdb50664480ef16bc57431ac739d4010133d2a2 98fc2289f1bf714314940fbb725d95ea15ced3f1
> commit - 3bdb50664480ef16bc57431ac739d4010133d2a2
> commit + 98fc2289f1bf714314940fbb725d95ea15ced3f1
> blob - 009561888bba0c0f18ea02211c6639bf87cfb368
> blob + 8295c80b38111178704802e1cfa5b090781c7ed5
> --- lib/got_lib_pkt.h
> +++ lib/got_lib_pkt.h
> @@ -20,6 +20,7 @@
>  const struct got_error *got_pkt_readn(ssize_t *off, int fd, void *buf,
>      size_t n);
>  const struct got_error *got_pkt_flushpkt(int fd, int chattygot);
> +const struct got_error *got_pkt_readlen(int *len, const char *str, int chattygot);
>  const struct got_error *got_pkt_readhdr(int *datalen, int fd, int chattygot);
>  const struct got_error *got_pkt_readpkt(int *outlen, int fd, char *buf,
>      int buflen, int chattygot);
> blob - fad7f03e4f70f1513ceb7af03bb71e1e7907a950
> blob + 6bb2b9c99379691b62c97f575b8b014e0c0e5a5d
> --- lib/pkt.c
> +++ lib/pkt.c
> @@ -58,6 +58,37 @@ got_pkt_flushpkt(int fd, int chattygot)
>  	return NULL;
>  }
>  
> +const struct got_error *
> +got_pkt_readlen(int *len, const char *str, int chattygot)
> +{
> +	char	*e;
> +	int	 i;
> +
> +	*len = 0;
> +	for (i = 0; i < 4; i++) {
> +		if (!isprint((unsigned char)str[i]))
> +			return got_error_msg(GOT_ERR_BAD_PACKET,
> +			    "unprintable character in pkt-line length field");
> +	}
> +	for (i = 0; i < 4; i++) {
> +		if (!isxdigit((unsigned char)str[i])) {
> +			if (chattygot)
> +				fprintf(stderr, "%s: bad length: '%s'\n",
> +				    getprogname(), str);
> +			return got_error_msg(GOT_ERR_BAD_PACKET,
> +			    "packet length not specified in hex");
> +		}
> +	}
> +	errno = 0;
> +	*len = strtol(str, &e, 16);
> +	if (str[0] == '\0' || *e != '\0')
> +		return got_error(GOT_ERR_BAD_PACKET);
> +	if (errno == ERANGE || *len > INT_MAX || *len < INT_MIN)
> +		return got_error_msg(GOT_ERR_BAD_PACKET, "bad pkt-line length");
> +
> +	return NULL;
> +}
> +
>  /*
>   * Packet header contains a 4-byte hexstring which specifies the length
>   * of data which follows.
> @@ -65,12 +96,10 @@ got_pkt_flushpkt(int fd, int chattygot)
>  const struct got_error *
>  got_pkt_readhdr(int *datalen, int fd, int chattygot)
>  {
> -	static const struct got_error *err = NULL;
> +	static const struct got_error *err;
>  	char lenstr[5];
> -	long len;
> -	char *e;
> -	int n, i;
>  	ssize_t r;
> +	int n;
>  
>  	*datalen = 0;
>  
> @@ -86,36 +115,14 @@ got_pkt_readhdr(int *datalen, int fd, int chattygot)
>  	if (r != 4)
>  		return got_error_msg(GOT_ERR_BAD_PACKET,
>  		    "wrong packet header length");
> -
>  	lenstr[4] = '\0';
> -	for (i = 0; i < 4; i++) {
> -		if (!isprint((unsigned char)lenstr[i]))
> -			return got_error_msg(GOT_ERR_BAD_PACKET,
> -			    "unprintable character in packet length field");
> -	}
> -	for (i = 0; i < 4; i++) {
> -		if (!isxdigit((unsigned char)lenstr[i])) {
> -			if (chattygot)
> -				fprintf(stderr, "%s: bad length: '%s'\n",
> -				    getprogname(), lenstr);
> -			return got_error_msg(GOT_ERR_BAD_PACKET,
> -			    "packet length not specified in hex");
> -		}
> -	}
> -	errno = 0;
> -	len = strtol(lenstr, &e, 16);
> -	if (lenstr[0] == '\0' || *e != '\0')
> -		return got_error(GOT_ERR_BAD_PACKET);
> -	if (errno == ERANGE && (len == LONG_MAX || len == LONG_MIN))
> -		return got_error_msg(GOT_ERR_BAD_PACKET, "bad packet length");
> -	if (len > INT_MAX || len < INT_MIN)
> -		return got_error_msg(GOT_ERR_BAD_PACKET, "bad packet length");
> -	n = len;
> +
> +	err = got_pkt_readlen(&n, lenstr, chattygot);
>  	if (n == 0)
> -		return NULL;
> +		return err;
>  	if (n <= 4)
>  		return got_error_msg(GOT_ERR_BAD_PACKET, "packet too short");
> -	n  -= 4;
> +	n -= 4;
>  
>  	*datalen = n;
>  	return NULL;
> 
>