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
<[email protected]> 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 <hurd/hurd_types.h>
> > #include <hurd/netfs.h>
> >
> > -/* 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 AAAA 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");
> > - return -1;
> > - }
> > + /* 1. Target selection.
> > + * If ip_addr (proxy global variable) is set, we use it.
> > + * Otherwise we use the node URL.
> > + */
> > + const char *target_host = (strcmp (ip_addr, "0.0.0.0") != 0) ?
> > ip_addr : node->url;
> > +
> > + /* 2. Agnostic resolution (IPv4/IPv6) */
> > + if ((err = lookup_host (target_host, &server_addr, &addr_len)) !=
> > 0) {
> > + fprintf (stderr, "Cannot resolve host: %s\n", target_host);
> > + return err;
> > + }
> > +
> > + /* 3. Set of the port. */
> > + if (server_addr.ss_family == AF_INET) {
> > + ((struct sockaddr_in *)&server_addr)->sin_port = htons
> > (port);
> > + } else if (server_addr.ss_family == AF_INET6) {
> > + ((struct sockaddr_in6 *)&server_addr)->sin6_port = htons
> > (port);
> > }
> >
> > if (debug_flag)
> > - fprintf (stderr, "trying to open %s:%d/%s\n", node->url,
> > - port, node->conn_req);
> > + fprintf (stderr, "Connecting to %s via %s:%d\n", node->url,
> > target_host, port);
> >
> > - *fd = socket (AF_INET, SOCK_STREAM, 0);
> > + /* 4. First connection: HEAD request */
> > + *fd = socket (server_addr.ss_family, SOCK_STREAM, 0);
>
> Ideally, you'd make lookup_host also take more parameters, to be filled
> by res->ai_socktype and res->ai_protocol, instead of hardcoding
> SOCK_STREAM and 0.
>
> > if (*fd == -1)
> > {
> > - fprintf(stderr,"Socket creation error\n");
> > + perror ("Socket creation error for HEAD request");
> > return errno;
> > }
> >
> > - err = connect (*fd, (struct sockaddr *)&dest, sizeof (dest));
> > - if (err == -1)
> > - {
> > - fprintf(stderr,"Cannot connect to remote host\n");
> > + if (connect (*fd, (struct sockaddr *)&server_addr, addr_len) == -1)
> > {
> > + perror ("Connection to remote host failed");
> > + close (*fd);
> > return errno;
> > }
> >
> > @@ -142,21 +177,20 @@ error_t open_connection(struct netnode *
> >
> > close(*fd);
> >
> > + /* 5. Second connection: GET request */
> > /* Send the GET request for the url */
> > - *fd = socket (AF_INET, SOCK_STREAM, 0);
> > + *fd = socket (server_addr.ss_family, SOCK_STREAM, 0);
>
> Ditto
>
> > if (*fd == -1)
> > {
> > - fprintf(stderr,"Socket creation error\n");
> > + perror ("Socket creation error for GET request");
> > return errno;
> > }
> >
> > - err = connect (*fd, (struct sockaddr *)&dest, sizeof (dest));
> > - if (err == -1)
> > - {
> > - fprintf(stderr,"Cannot connect to remote host\n");
> > + if (connect (*fd, (struct sockaddr *)&server_addr, addr_len) == -1)
> > {
> > + perror ("Connection to remote host failed");
> > + close (*fd);
> > return errno;
> > }
> > -
> > towrite = strlen (node->comm_buf);
> >
> > /* guard against EINTR failures */
> > Index: httpfs/httpfs.h
> > ===================================================================
> > --- httpfs.orig/httpfs.h
> > +++ httpfs/httpfs.h
> > @@ -119,8 +119,8 @@ error_t parse(struct netnode *node);
> > * string */
> > void extract(char *string,char *parent);
> >
> > -/* 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 *url, struct sockaddr_storage *dest,
> > socklen_t *dest_len);
> >
> > /* store the remote socket in *FD and establish the connection and send the
> > * http GET request */
>
Index: httpfs/http.c
===================================================================
--- httpfs.orig/http.c
+++ httpfs/http.c
@@ -35,15 +35,12 @@
#include <hurd/netfs.h>
/* 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)
+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, ']');
- if (end) {
- size_t host_len = end - host - 1;
- if (host_len >= sizeof (clean_host)) return ENAMETOOLONG;
-
- strncpy (clean_host, host + 1, host_len);
- clean_host[host_len] = '\0';
- host_ptr = clean_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];
+
+ /* Copy the content between square brackets */
+ allocated_host = strndup (host + 1, host_len - 2);
+ if (!allocated_host)
+ return ENOMEM;
+
+ host = allocated_host;
}
- memset (&hints, 0, sizeof (struct addrinfo));
+ memset (&hints, 0, sizeof (hints));
hints.ai_family = AF_UNSPEC; /* IPv4 and IPv6 */
hints.ai_socktype = SOCK_STREAM; /* TCP */
/* AI_ADDRCONFIG: Asks for AAAA record only if the host has IPv6 connectivity.
@@ -71,19 +75,25 @@ error_t lookup_host (const char *host, s
hints.ai_flags = AI_ADDRCONFIG | AI_V4MAPPED;
/* DNS lookup */
- s = getaddrinfo (host_ptr, NULL, &hints, &res);
+ s = getaddrinfo (host, NULL, &hints, &res);
+
+ if (allocated_host)
+ free (allocated_host);
+
if (s != 0) {
if (debug_flag)
- fprintf (stderr, "DNS lookup failed for %s: %s\n", host_ptr, gai_strerror (s));
+ fprintf (stderr, "DNS lookup failed for %s: %s\n", host, gai_strerror (s));
return ENOENT;
}
- /* TODO: Shall we copy only the first result or iterate through possible multiple results */
+ /* TODO: Ideally we shoud loop through the result, but taking the first one is ok for now */
if (res != NULL) {
memcpy (dest, res->ai_addr, res->ai_addrlen);
*dest_len = res->ai_addrlen;
- dest->ss_family = res->ai_family;
+
+ if (socktype) *socktype = res->ai_socktype;
+ if (protocol) *protocol = res->ai_protocol;
}
freeaddrinfo (res);
@@ -99,6 +109,8 @@ error_t open_connection(struct netnode *
error_t err;
struct sockaddr_storage server_addr;
socklen_t addr_len;
+ int sock_type = 0;
+ int protocol = 0;
ssize_t written;
size_t towrite;
char buffer[4096];
@@ -115,7 +127,7 @@ error_t open_connection(struct netnode *
const char *target_host = (strcmp (ip_addr, "0.0.0.0") != 0) ? ip_addr : node->url;
/* 2. Agnostic resolution (IPv4/IPv6) */
- if ((err = lookup_host (target_host, &server_addr, &addr_len)) != 0) {
+ if ((err = lookup_host (target_host, &server_addr, &addr_len, &sock_type, &protocol)) != 0) {
fprintf (stderr, "Cannot resolve host: %s\n", target_host);
return err;
}
@@ -131,7 +143,7 @@ error_t open_connection(struct netnode *
fprintf (stderr, "Connecting to %s via %s:%d\n", node->url, target_host, port);
/* 4. First connection: HEAD request */
- *fd = socket (server_addr.ss_family, SOCK_STREAM, 0);
+ *fd = socket (server_addr.ss_family, sock_type, protocol);
if (*fd == -1)
{
perror ("Socket creation error for HEAD request");
@@ -179,7 +191,7 @@ error_t open_connection(struct netnode *
/* 5. Second connection: GET request */
/* Send the GET request for the url */
- *fd = socket (server_addr.ss_family, SOCK_STREAM, 0);
+ *fd = socket (server_addr.ss_family, sock_type, protocol);
if (*fd == -1)
{
perror ("Socket creation error for GET request");
Index: httpfs/httpfs.h
===================================================================
--- httpfs.orig/httpfs.h
+++ httpfs/httpfs.h
@@ -120,7 +120,7 @@ error_t parse(struct netnode *node);
void extract(char *string,char *parent);
/* do a DNS lookup for HOST and store result in *DEST */
-error_t lookup_host (const char *url, struct sockaddr_storage *dest, socklen_t *dest_len);
+error_t lookup_host (const char *url, struct sockaddr_storage *dest, socklen_t *dest_len, int *socktype, int *protocol);
/* store the remote socket in *FD and establish the connection and send the
* http GET request */
