Re: [PATCH] httpfs: add IPv6 support and modernize network logic
Hello,
Gianluca Cannata, le sam. 24 janv. 2026 15:26:53 +0100, a ecrit:
> -error_t lookup_host (const char *host, struct sockaddr_storage *dest,
> socklen_t *dest_len)
> +error_t lookup_host (const char *host, struct sockaddr_storage *dest,
> socklen_t *dest_len, int *socktype, int *protocol)
> {
> struct addrinfo hints;
> struct addrinfo *res;
> int s;
> -
> - /* Buffer that holds a clean host, that is a host without square
> brackets in case of a IPv6 address */
> - char clean_host[256];
> - const char *host_ptr = host;
> + char *allocated_host = NULL;
>
> if (!host || !dest || !dest_len)
> return EINVAL;
> @@ -52,18 +49,25 @@ error_t lookup_host (const char *host, s
> * because getaddrinfo does not accept square brackets, but URLs do.
> */
> if (host[0] == '[') {
> - const char *end = strchr (host, ']');
> + size_t host_len = strlen (host);
> +
> + /* If it starts with a [, it must also ends with a ] */
> + if (host[host_len - 1] != ']')
> + return EINVAL;
> +
> + /* We allocate only the necessary memory with a VLA (C99) */
> + size_t clean_len = host_len - 2;
> + char clean_host[clean_len + 1];
This is unused, since you just strdup below, which is fine:
> +
> + /* Copy the content between square brackets */
> + allocated_host = strndup (host + 1, host_len - 2);
> + if (!allocated_host)
> + return ENOMEM;
> +
> + host = allocated_host;
> }
Please send a patch with the complete changes, so I can apply it in one
go.
Samuel
Re: [PATCH] httpfs: add IPv6 support and modernize network logic
Hi Samuel,
Thank you for your feedback.
I should have addressed all the required changes.
Let me know what you think.
Cheers,
Gianluca
Il giorno gio 22 gen 2026 alle ore 00:53 Samuel Thibault
ha scritto:
>
> Hello,
>
> Thanks for this, it's indeed useful and well-contained for a
> contribution.
>
> Samuel
>
> Gianluca Cannata, le mer. 21 janv. 2026 09:31:37 +0100, a ecrit:
> > Index: httpfs/http.c
> > ===
> > --- httpfs.orig/http.c
> > +++ httpfs/http.c
> > @@ -34,14 +34,59 @@
> > #include
> > #include
> >
> > -/* do a DNS lookup for NAME and store result in *ENT */
> > -error_t lookup_host (char *url, struct hostent **ent)
> > +/* do a DNS lookup for HOST and store result in *DEST */
> > +error_t lookup_host (const char *host, struct sockaddr_storage *dest,
> > socklen_t *dest_len)
> > {
> > - if ( (*ent = gethostbyname(url)) == NULL )
> > - {
> > - fprintf(stderr,"wrong host name\n");
> > + struct addrinfo hints;
> > + struct addrinfo *res;
> > + int s;
> > +
> > + /* Buffer that holds a clean host, that is a host without square
> > brackets in case of a IPv6 address */
> > + char clean_host[256];
>
> Rather than hard-coding 256, you can use strlen(host)-1. Then you won't
> have an ENAMETOOLONG error.
>
> > + const char *host_ptr = host;
>
> You don't need a separate host_ptr variable. When using clean_host, you
> can as well just do host = clean_host.
>
> > + if (!host || !dest || !dest_len)
> > return EINVAL;
> > +
> > + /* IPv6 syntax transformation: e.g. [2001:db8::1] -> 2001:db8::1
> > +* because getaddrinfo does not accept square brackets, but URLs do.
> > +*/
> > + if (host[0] == '[') {
> > + const char *end = strchr (host, ']');
>
> If you have an opening bracket, the closing bracket should be the last
> character anyway, so you can as well directly check for ']' at the end,
> and return EINVAL otherwise.
>
> > + if (end) {
> > + size_t host_len = end - host - 1;
> > + if (host_len >= sizeof (clean_host)) return
> > ENAMETOOLONG;
> > +
> > + strncpy (clean_host, host + 1, host_len);
>
> Better use memcpy.
>
> > + clean_host[host_len] = '\0';
> > + host_ptr = clean_host;
> > + }
> > }
> > +
> > + memset (&hints, 0, sizeof (struct addrinfo));
>
> better use sizeof(hints), which we then know for sure is correct.
>
> > + hints.ai_family = AF_UNSPEC; /* IPv4 and IPv6 */
> > + hints.ai_socktype = SOCK_STREAM; /* TCP */
> > + /* AI_ADDRCONFIG: Asks for record only if the host has IPv6
> > connectivity.
> > +* AI_V4MAPPED: Maps IPv4 to IPv6 if necessary. */
> > + hints.ai_flags = AI_ADDRCONFIG | AI_V4MAPPED;
> > +
> > + /* DNS lookup */
> > + s = getaddrinfo (host_ptr, NULL, &hints, &res);
> > + if (s != 0) {
> > + if (debug_flag)
> > + fprintf (stderr, "DNS lookup failed for %s: %s\n",
> > host_ptr, gai_strerror (s));
> > +
> > + return ENOENT;
> > + }
> > +
> > + /* TODO: Shall we copy only the first result or iterate through
> > possible multiple results */
>
> Ideally we'd try to connect to each result until one succeeds. But that
> will do for now.
>
> > + if (res != NULL) {
> > + memcpy (dest, res->ai_addr, res->ai_addrlen);
> > + *dest_len = res->ai_addrlen;
> > + dest->ss_family = res->ai_family;
>
> res->ai_addr.sa_family will already have filled dest->ss_family, no need
> to fill it again.
>
> > + }
> > +
> > + freeaddrinfo (res);
> > return 0;
> > }
> >
> > @@ -52,8 +97,8 @@ error_t open_connection(struct netnode *
> > * head. *HEAD_LEN indicates the header length, for pruning upto
> > that */
> >
> > error_t err;
> > - struct hostent *hptr;
> > - struct sockaddr_in dest;
> > + struct sockaddr_storage server_addr;
> > + socklen_t addr_len;
> > ssize_t written;
> > size_t towrite;
> > char buffer[4096];
> > @@ -63,49 +108,39 @@ error_t open_connection(struct netnode *
> > char delimiters0[] = " ";
> > char delimiters1[] = "\n";
> >
> > - bzero(&dest,sizeof(dest));
> > - dest.sin_family = AF_INET;
> > - dest.sin_port = htons (port);
> > -
> > - if ( !strcmp(ip_addr,"0.0.0.0") )
> > - {
> > - /* connection is not through a proxy server
> > -* find IP addr. of remote server */
> > - err = lookup_host (node->url, &hptr);
> > - if (err)
> > - {
> > - fprintf(stderr,"Could not find IP addr
> > %s\n",node->url);
> > - return err;
> > -
Re: [PATCH] httpfs: add IPv6 support and modernize network logic
Hello,
Thanks for this, it's indeed useful and well-contained for a
contribution.
Samuel
Gianluca Cannata, le mer. 21 janv. 2026 09:31:37 +0100, a ecrit:
> Index: httpfs/http.c
> ===
> --- httpfs.orig/http.c
> +++ httpfs/http.c
> @@ -34,14 +34,59 @@
> #include
> #include
>
> -/* do a DNS lookup for NAME and store result in *ENT */
> -error_t lookup_host (char *url, struct hostent **ent)
> +/* do a DNS lookup for HOST and store result in *DEST */
> +error_t lookup_host (const char *host, struct sockaddr_storage *dest,
> socklen_t *dest_len)
> {
> - if ( (*ent = gethostbyname(url)) == NULL )
> - {
> - fprintf(stderr,"wrong host name\n");
> + struct addrinfo hints;
> + struct addrinfo *res;
> + int s;
> +
> + /* Buffer that holds a clean host, that is a host without square
> brackets in case of a IPv6 address */
> + char clean_host[256];
Rather than hard-coding 256, you can use strlen(host)-1. Then you won't
have an ENAMETOOLONG error.
> + const char *host_ptr = host;
You don't need a separate host_ptr variable. When using clean_host, you
can as well just do host = clean_host.
> + if (!host || !dest || !dest_len)
> return EINVAL;
> +
> + /* IPv6 syntax transformation: e.g. [2001:db8::1] -> 2001:db8::1
> +* because getaddrinfo does not accept square brackets, but URLs do.
> +*/
> + if (host[0] == '[') {
> + const char *end = strchr (host, ']');
If you have an opening bracket, the closing bracket should be the last
character anyway, so you can as well directly check for ']' at the end,
and return EINVAL otherwise.
> + if (end) {
> + size_t host_len = end - host - 1;
> + if (host_len >= sizeof (clean_host)) return
> ENAMETOOLONG;
> +
> + strncpy (clean_host, host + 1, host_len);
Better use memcpy.
> + clean_host[host_len] = '\0';
> + host_ptr = clean_host;
> + }
> }
> +
> + memset (&hints, 0, sizeof (struct addrinfo));
better use sizeof(hints), which we then know for sure is correct.
> + hints.ai_family = AF_UNSPEC; /* IPv4 and IPv6 */
> + hints.ai_socktype = SOCK_STREAM; /* TCP */
> + /* AI_ADDRCONFIG: Asks for record only if the host has IPv6
> connectivity.
> +* AI_V4MAPPED: Maps IPv4 to IPv6 if necessary. */
> + hints.ai_flags = AI_ADDRCONFIG | AI_V4MAPPED;
> +
> + /* DNS lookup */
> + s = getaddrinfo (host_ptr, NULL, &hints, &res);
> + if (s != 0) {
> + if (debug_flag)
> + fprintf (stderr, "DNS lookup failed for %s: %s\n",
> host_ptr, gai_strerror (s));
> +
> + return ENOENT;
> + }
> +
> + /* TODO: Shall we copy only the first result or iterate through
> possible multiple results */
Ideally we'd try to connect to each result until one succeeds. But that
will do for now.
> + if (res != NULL) {
> + memcpy (dest, res->ai_addr, res->ai_addrlen);
> + *dest_len = res->ai_addrlen;
> + dest->ss_family = res->ai_family;
res->ai_addr.sa_family will already have filled dest->ss_family, no need
to fill it again.
> + }
> +
> + freeaddrinfo (res);
> return 0;
> }
>
> @@ -52,8 +97,8 @@ error_t open_connection(struct netnode *
> * head. *HEAD_LEN indicates the header length, for pruning upto that
> */
>
> error_t err;
> - struct hostent *hptr;
> - struct sockaddr_in dest;
> + struct sockaddr_storage server_addr;
> + socklen_t addr_len;
> ssize_t written;
> size_t towrite;
> char buffer[4096];
> @@ -63,49 +108,39 @@ error_t open_connection(struct netnode *
> char delimiters0[] = " ";
> char delimiters1[] = "\n";
>
> - bzero(&dest,sizeof(dest));
> - dest.sin_family = AF_INET;
> - dest.sin_port = htons (port);
> -
> - if ( !strcmp(ip_addr,"0.0.0.0") )
> - {
> - /* connection is not through a proxy server
> -* find IP addr. of remote server */
> - err = lookup_host (node->url, &hptr);
> - if (err)
> - {
> - fprintf(stderr,"Could not find IP addr
> %s\n",node->url);
> - return err;
> - }
> - dest.sin_addr = *(struct in_addr *)hptr->h_addr;
> - }
> - else
> - {
> - /* connection is through the proxy server
> -* need not find IP of remote server
> -* find IP of the proxy server */
> - if ( inet_aton(ip_addr,&dest.sin_addr) == 0 )
> - {
> - fprintf(stderr,"Invalid IP for proxy\n");
> -
