From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: passt.top; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=VG3vqT4o; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by passt.top (Postfix) with ESMTPS id DA3ED5A026F for ; Tue, 21 Oct 2025 11:33:13 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1761039192; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JMKpiBigFp1obditK9B+8TEIV38hkceT5yEB/9TAnos=; b=VG3vqT4oS9UtgCdwh9SyvE6nFLm2dofFi8+Vw/XE0/pOP8YKIm6SMhAIU0b05l1PUptLjJ yA7SOZVjrg+jUHvrf+4PjKMUip5L3MHCT8Enr0BnKpACAjnobzYLhlm19fOn+H/357CgE+ hO/m9Ziwo6uxPBkCL24Kfqf2hofaBho= Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-94-mHY7tpKNPqqZYvm_Adrxmg-1; Tue, 21 Oct 2025 05:33:11 -0400 X-MC-Unique: mHY7tpKNPqqZYvm_Adrxmg-1 X-Mimecast-MFC-AGG-ID: mHY7tpKNPqqZYvm_Adrxmg_1761039190 Received: by mail-ed1-f71.google.com with SMTP id 4fb4d7f45d1cf-634700fe857so6928527a12.0 for ; Tue, 21 Oct 2025 02:33:10 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761039190; x=1761643990; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=JMKpiBigFp1obditK9B+8TEIV38hkceT5yEB/9TAnos=; b=l7HsN6zAENYT+mtBpJiNw+GwIouUDFv18WQuRWx+aXXOW37zmV/vp2bUAMydfrzYRd GgKaOi5PZ6knZuBPEcS0rCd6/lguekWUBp6DzcHUhu1eG3BR8x1pWPKeq6nId8vJoA0m CR7+vYjzFwvOeJVp5Orl562rW5yS2F24O21zVMBv22RoJOTR8onETIepT3WJJB1/N08k /WFGPlHv6iWFcbcLbeM+Fjvp44BlCm8quQhnflKb/MZ0nghqJcsR+3g8Vdj2LqXFkDIE Ptn5mFnmAunaMCvrvVmetmEhjQCBonAiKbfO28r2OJTtYz2BmL0SFoVuVxLbF6ahvP+p wVbg== X-Gm-Message-State: AOJu0Yybm3SOijZsU2YRyn6+DxUV/YnKF2fE5qwmVVhAf34c8mLJLA5n 1mg/bi0WMl2EzPFu/BAn4ZGUGNAhv217cxUS0SwAiGnGc+oRkmHEpgLWHmt49JotTYhuRPIwCJk T2GpDtmucTN9vOVYfaujTvVEML2eX2WN3sk30ZcLnOc+BhVxvoXDIC54hkeaCFU1kR5Aqp8Ky6U l756YIYlMUfwDeBthq6k1JD0kBLzgV X-Gm-Gg: ASbGncs2y8zmpVxKGrmHtKajvhXWVmSoI8BxmiMXFi453qr0g6eSl8qQ2agc7l93dzJ TubX5AnmHIq0QzTMabkIghq5Yz6OqqeV4ejOPl5AF/CUjUqQQAE0N1nk4x4kVxLTOJPrLWCNHU0 WRonoIWag4QnlKwAPPwcICG2jEzy1JbA33+N/MPhVGDRUlifGivRG2fx0B X-Received: by 2002:a05:6402:2713:b0:639:e5da:637e with SMTP id 4fb4d7f45d1cf-63c1e1f212fmr15938184a12.6.1761039189863; Tue, 21 Oct 2025 02:33:09 -0700 (PDT) X-Google-Smtp-Source: AGHT+IH2gPJG2P0OqfXHTX6lr+xqhQFVbZ/bPv0Lkupvt5hxnSfJqUopYkA+Lu54Jv1PSrCwcvCRE6ZsZoUk3bDdIIE= X-Received: by 2002:a05:6402:2713:b0:639:e5da:637e with SMTP id 4fb4d7f45d1cf-63c1e1f212fmr15938158a12.6.1761039189386; Tue, 21 Oct 2025 02:33:09 -0700 (PDT) MIME-Version: 1.0 References: <20251017062838.21041-1-yuhuang@redhat.com> <20251017062838.21041-3-yuhuang@redhat.com> <20251019120712.6f232804@elisabeth> In-Reply-To: <20251019120712.6f232804@elisabeth> From: Yumei Huang Date: Tue, 21 Oct 2025 17:32:58 +0800 X-Gm-Features: AS18NWD12Nhxc5wxoReDNnXFmSBT0W-ijU_rFOltSg86Tu732eajW4LP5J60yj0 Message-ID: Subject: Re: [PATCH v6 2/4] util: Introduce read_file() and read_file_integer() function To: Stefano Brivio X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: xqkybqELbheNPaySDVaPIjR9sDnL_s1_ftlTtlFZSnA_1761039190 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Message-ID-Hash: OJKADYVG2UFEHQ2NQ5B656HPCZWSVH4X X-Message-ID-Hash: OJKADYVG2UFEHQ2NQ5B656HPCZWSVH4X X-MailFrom: yuhuang@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: passt-dev@passt.top, david@gibson.dropbear.id.au X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Sun, Oct 19, 2025 at 6:07=E2=80=AFPM Stefano Brivio = wrote: > > On Fri, 17 Oct 2025 14:28:36 +0800 > Yumei Huang wrote: > > > Signed-off-by: Yumei Huang > > --- > > util.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > util.h | 8 ++++++ > > 2 files changed, 92 insertions(+) > > > > diff --git a/util.c b/util.c > > index c492f90..5c8c4bc 100644 > > --- a/util.c > > +++ b/util.c > > @@ -579,6 +579,90 @@ int write_file(const char *path, const char *buf) > > return len =3D=3D 0 ? 0 : -1; > > } > > > > +/** > > + * read_file() - Read contents of file into a buffer > > + * @path: File to read > > + * @buf: Buffer to store file contents > > + * @buf_size: Size of buffer > > + * > > + * Return: number of bytes read on success, -1 on any error, -2 on tru= ncation > > +*/ > > +ssize_t read_file(const char *path, char *buf, size_t buf_size) > > +{ > > + int fd =3D open(path, O_RDONLY | O_CLOEXEC); > > + size_t total_read =3D 0; > > + ssize_t rc; > > + > > + if (fd < 0) { > > + warn_perror("Could not open %s", path); > > + return -1; > > + } > > + > > + while (total_read < buf_size) { > > + rc =3D read(fd, buf + total_read, buf_size - total_read); > > + > > + if (rc < 0) { > > + warn_perror("Couldn't read from %s", path); > > + close(fd); > > + return -1; > > + } > > + > > + if (rc =3D=3D 0) > > + break; > > + > > + total_read +=3D rc; > > + } > > + > > + close(fd); > > + > > + if (total_read =3D=3D buf_size) { > > + warn("File %s truncated, buffer too small", path); > > + return -2; > > + } > > + > > + buf[total_read] =3D '\0'; > > + > > + return total_read; > > +} > > + > > +/** > > + * read_file_integer() - Read an integer value from a file > > + * @path: File to read > > + * @fallback: Default value if file can't be read > > + * > > + * Return: Integer value, fallback on failure > > +*/ > > +intmax_t read_file_integer(const char *path, intmax_t fallback) > > +{ > > + char buf[INTMAX_STRLEN]; > > + ssize_t bytes_read; > > + intmax_t value; > > + char *end; > > + > > + bytes_read =3D read_file(path, buf, sizeof(buf)); > > + > > + if (bytes_read < 0) > > + return fallback; > > + > > + if (bytes_read =3D=3D 0) { > > + debug("Empty file %s", path); > > + return fallback; > > + } > > + > > + errno =3D 0; > > + value =3D strtoimax(buf, &end, 10); > > + if (*end && *end !=3D '\n') { > > + debug("Invalid format in %s", path); > > + return fallback; > > + } > > + if (errno) { > > + debug("Invalid value in %s: %s", path, buf); > > + return fallback; > > + } > > + > > + return value; > > +} > > + > > #ifdef __ia64__ > > /* Needed by do_clone() below: glibc doesn't export the prototype of _= _clone2(), > > * use the description from clone(2). > > diff --git a/util.h b/util.h > > index 22eaac5..3f9f296 100644 > > --- a/util.h > > +++ b/util.h > > @@ -222,6 +222,8 @@ void pidfile_write(int fd, pid_t pid); > > int __daemon(int pidfile_fd, int devnull_fd); > > int fls(unsigned long x); > > int write_file(const char *path, const char *buf); > > +ssize_t read_file(const char *path, char *buf, size_t buf_size); > > +intmax_t read_file_integer(const char *path, intmax_t fallback); > > int write_all_buf(int fd, const void *buf, size_t len); > > int write_remainder(int fd, const struct iovec *iov, size_t iovcnt, si= ze_t skip); > > int read_all_buf(int fd, void *buf, size_t len); > > @@ -250,6 +252,12 @@ static inline const char *af_name(sa_family_t af) > > > > #define UINT16_STRLEN (sizeof("65535")) > > > > +/* Each byte expands to at most 3 decimal digits since 0xff =3D=3D 255= . > > + * Plus 2 extra bytes for the sign and null terminator. > > + * See https://stackoverflow.com/a/10536254. > > This is not an acceptable form of attribution according to the > CC BY-SA 3.0 terms. See: > > https://stackoverflow.com/help/licensing > https://creativecommons.org/licenses/by-sa/3.0/ > > and checksum.h in this tree for some examples of how to combine > different licensing terms in a single file, in a way that's > human-readable but still machine-friendly (for license / compliance > scanners such as REUSE). > > As I commented on a previous version, anyway, I don't think we need > this at all. I guess my comment was ignored though. I guess you meant the comment of suggesting using BUFSIZ in V2? David replied as quote: "We could use BUFSIZ, but it's massive overkill for reading a single integer: 8192 versus ~21 bytes (or ~42 bytes if intmax_t were 128-bit)." It's my fault. I should have waited to see if you have more comments before sending the new version. > > Note that I didn't review this patch or the rest of this series, yet. > > -- > Stefano > -- Thanks, Yumei Huang