add stubs of missing libc functions

components/libssh/compat/netinet/tcp.h

@@ -0,0 +1 @@
+/* lwip doesn't provide this file */

components/libssh/compat/poll.h

@@ -0,0 +1,2 @@
+/* esp-idf has <sys/poll.h> but not <poll.h> */
+#include <sys/poll.h>

components/libssh/compat/stubs.h

@@ -0,0 +1,31 @@
+#include <net/if.h>
+#include <pwd.h>
+#include <glob.h>
+
+#if !defined(GLOB_NOMATCH)
+#define GLOB_NOMATCH -3
+#endif
+
+#define gai_strerror(ecode) "unknown error"
+#define getuid() getuid_stub() (uid_t)0
+
+static inline int getpwuid_r_stub(struct passwd **result) { errno = ENOENT; *result = NULL; return 1; }
+#define getpwuid_r(uid,passwd,buffer,buflen,result) getpwuid_r_stub(result)
+
+static inline struct passwd *getpwnam_stub() { errno = ENOENT; return NULL; }
+#define getpwnam(name) getpwnam_stub()
+
+static inline int gethostname_stub(char *name, size_t namelen) {strlcpy(name, "esp32", namelen); return 0; }
+#define gethostname(name, namelen) gethostname_stub(name, namelen)
+
+static inline pid_t waitpid_stub() { errno = ENOSYS; return (pid_t)-1; }
+#define waitpid(pid,status,options) waitpid_stub()
+
+static inline int glob_stub() { errno = ENOENT; return GLOB_NOMATCH; }
+#define glob(pattern, flags, errfunc, pglob) glob_stub()
+
+#define globfree(pglob) do { } while(0)
+
+
+static inline int socketpair_stub() { errno = ENOSYS; return -1; }
+#define socketpair(d, type, protocol, sv) socketpair_stub()